diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index f9c5367..9d8abf8 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -757,6 +757,7 @@
 	$(OUTDIR)/normal.o \
 	$(OUTDIR)/ops.o \
 	$(OUTDIR)/option.o \
+	$(OUTDIR)/optionstr.o \
 	$(OUTDIR)/os_mswin.o \
 	$(OUTDIR)/os_win32.o \
 	$(OUTDIR)/pathdef.o \
diff --git a/src/Make_morph.mak b/src/Make_morph.mak
index 3f896da..87b7e45 100644
--- a/src/Make_morph.mak
+++ b/src/Make_morph.mak
@@ -76,6 +76,7 @@
 	normal.c						\
 	ops.c							\
 	option.c						\
+	optionstr.c						\
 	os_amiga.c						\
 	popupmnu.c						\
 	profiler.c						\
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 7aa7ef8..1205a6e 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -764,6 +764,7 @@
 	$(OUTDIR)\normal.obj \
 	$(OUTDIR)\ops.obj \
 	$(OUTDIR)\option.obj \
+	$(OUTDIR)\optionstr.obj \
 	$(OUTDIR)\os_mswin.obj \
 	$(OUTDIR)\os_win32.obj \
 	$(OUTDIR)\pathdef.obj \
@@ -1606,6 +1607,8 @@
 
 $(OUTDIR)/option.obj:	$(OUTDIR) option.c  $(INCL) optiondefs.h
 
+$(OUTDIR)/optionstr.obj:	$(OUTDIR) optionstr.c  $(INCL)
+
 $(OUTDIR)/ops.obj:	$(OUTDIR) ops.c  $(INCL)
 
 $(OUTDIR)/os_mswin.obj:	$(OUTDIR) os_mswin.c  $(INCL)
@@ -1816,6 +1819,7 @@
 	proto/normal.pro \
 	proto/ops.pro \
 	proto/option.pro \
+	proto/optionstr.pro \
 	proto/os_mswin.pro \
 	proto/winclip.pro \
 	proto/os_win32.pro \
diff --git a/src/Make_vms.mms b/src/Make_vms.mms
index c3b7958..42adcb8 100644
--- a/src/Make_vms.mms
+++ b/src/Make_vms.mms
@@ -317,8 +317,8 @@
 	getchar.c hardcopy.c hashtab.c highlight.c \
 	indent.c insexpand.c json.c list.c main.c map.c mark.c menu.c mbyte.c \
 	memfile.c memline.c message.c misc1.c misc2.c move.c normal.c ops.c \
-	option.c popupmnu.c popupwin.c profiler.c quickfix.c regexp.c \
-	scriptfile.c \
+	option.c optionstr.c popupmnu.c popupwin.c profiler.c quickfix.c \
+	regexp.c scriptfile.c \
 	search.c session.c sha256.c sign.c spell.c spellfile.c syntax.c tag.c \
 	term.c termlib.c testing.c textprop.c ui.c undo.c usercmd.c \
 	userfunc.c version.c viminfo.c screen.c window.c os_unix.c os_vms.c \
@@ -337,8 +337,8 @@
 	highlight.obj indent.obj insexpand.obj json.obj list.obj main.obj \
 	map.obj mark.obj menu.obj memfile.obj memline.obj message.obj \
 	misc1.obj misc2.obj move.obj mbyte.obj normal.obj ops.obj option.obj \
-	popupmnu.obj popupwin.obj profiler.obj quickfix.obj regexp.obj \
-	scriptfile.obj \
+	optionstr.obj popupmnu.obj popupwin.obj profiler.obj quickfix.obj \
+	regexp.obj scriptfile.obj \
 	search.obj session.obj sha256.obj sign.obj spell.obj spellfile.obj \
 	syntax.obj tag.obj term.obj termlib.obj testing.obj textprop.obj \
 	ui.obj undo.obj usercmd.obj userfunc.obj screen.obj version.obj \
@@ -715,6 +715,10 @@
  ascii.h keymap.h term.h macros.h structs.h regexp.h \
  gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
  globals.h optiondefs.h
+optionstr.obj : optionstr.c vim.h [.auto]config.h feature.h os_unix.h \
+ ascii.h keymap.h term.h macros.h structs.h regexp.h \
+ gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
+ globals.h
 os_unix.obj : os_unix.c vim.h [.auto]config.h feature.h os_unix.h \
  ascii.h keymap.h term.h macros.h structs.h regexp.h \
  gui.h beval.h [.proto]gui_beval.pro option.h ex_cmds.h proto.h \
diff --git a/src/Makefile b/src/Makefile
index 0efd88f7..c89fdb1 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1632,6 +1632,7 @@
 	normal.c \
 	ops.c \
 	option.c \
+	optionstr.c \
 	os_unix.c \
 	auto/pathdef.c \
 	popupmnu.c \
@@ -1762,6 +1763,7 @@
 	objects/normal.o \
 	objects/ops.o \
 	objects/option.o \
+	objects/optionstr.o \
 	objects/os_unix.o \
 	objects/pathdef.o \
 	objects/popupmnu.o \
@@ -1917,6 +1919,7 @@
 	normal.pro \
 	ops.pro \
 	option.pro \
+	optionstr.pro \
 	os_mac_conv.pro \
 	os_unix.pro \
 	popupmnu.pro \
@@ -3287,6 +3290,9 @@
 objects/option.o: option.c optiondefs.h
 	$(CCC_NF) $(LUA_CFLAGS) $(PERL_CFLAGS) $(PYTHON_CFLAGS) $(PYTHON3_CFLAGS) $(RUBY_CFLAGS) $(TCL_CFLAGS) $(ALL_CFLAGS) -o $@ option.c
 
+objects/optionstr.o: optionstr.c
+	$(CCC_NF) $(LUA_CFLAGS) $(PERL_CFLAGS) $(PYTHON_CFLAGS) $(PYTHON3_CFLAGS) $(RUBY_CFLAGS) $(TCL_CFLAGS) $(ALL_CFLAGS) -o $@ optionstr.c
+
 objects/os_beos.o: os_beos.c
 	$(CCC) -o $@ os_beos.c
 
@@ -3763,6 +3769,10 @@
  auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
  proto.h globals.h optiondefs.h
+objects/optionstr.o: optionstr.c vim.h protodef.h auto/config.h feature.h os_unix.h \
+ auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
+ proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
+ proto.h globals.h
 objects/os_unix.o: os_unix.c vim.h protodef.h auto/config.h feature.h os_unix.h \
  auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
diff --git a/src/README.md b/src/README.md
index 6ba8391..f4f9df1 100644
--- a/src/README.md
+++ b/src/README.md
@@ -54,6 +54,7 @@
 message.c	| (error) messages
 ops.c		| handling operators ("d", "y", "p")
 option.c	| options
+optionstr.c	| handling string options
 popupmnu.c	| popup menu
 popupwin.c	| popup window
 profiler.c	| vim script profiler
diff --git a/src/ops.c b/src/ops.c
index 5f0181b..89a25b1 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -315,14 +315,14 @@
 {
     int		count;
     int		i, j;
-    int		p_sw = (int)get_sw_value_indent(curbuf);
+    int		sw_val = (int)get_sw_value_indent(curbuf);
 
     count = get_indent();	/* get current indent */
 
     if (round)			/* round off indent */
     {
-	i = count / p_sw;	/* number of p_sw rounded down */
-	j = count % p_sw;	/* extra spaces */
+	i = count / sw_val;	/* number of p_sw rounded down */
+	j = count % sw_val;	/* extra spaces */
 	if (j && left)		/* first remove extra spaces */
 	    --amount;
 	if (left)
@@ -333,18 +333,18 @@
 	}
 	else
 	    i += amount;
-	count = i * p_sw;
+	count = i * sw_val;
     }
     else		/* original vi indent */
     {
 	if (left)
 	{
-	    count -= p_sw * amount;
+	    count -= sw_val * amount;
 	    if (count < 0)
 		count = 0;
 	}
 	else
-	    count += p_sw * amount;
+	    count += sw_val * amount;
     }
 
     /* Set new indent */
@@ -366,11 +366,8 @@
     int			total;
     char_u		*newp, *oldp;
     int			oldcol = curwin->w_cursor.col;
-    int			p_sw = (int)get_sw_value_indent(curbuf);
-#ifdef FEAT_VARTABS
-    int			*p_vts = curbuf->b_p_vts_array;
-#endif
-    int			p_ts = (int)curbuf->b_p_ts;
+    int			sw_val = (int)get_sw_value_indent(curbuf);
+    int			ts_val = (int)curbuf->b_p_ts;
     struct block_def	bd;
     int			incr;
     colnr_T		ws_vcol;
@@ -388,8 +385,8 @@
 	return;
 
     /* total is number of screen columns to be inserted/removed */
-    total = (int)((unsigned)amount * (unsigned)p_sw);
-    if ((total / p_sw) != amount)
+    total = (int)((unsigned)amount * (unsigned)sw_val);
+    if ((total / sw_val) != amount)
 	return; /* multiplication overflow */
 
     oldp = ml_get_curline();
@@ -431,14 +428,15 @@
 	 * non-ws char in the block. */
 #ifdef FEAT_VARTABS
 	if (!curbuf->b_p_et)
-	    tabstop_fromto(ws_vcol, ws_vcol + total, p_ts, p_vts, &i, &j);
+	    tabstop_fromto(ws_vcol, ws_vcol + total,
+					ts_val, curbuf->b_p_vts_array, &i, &j);
 	else
 	    j = total;
 #else
 	if (!curbuf->b_p_et)
-	    i = ((ws_vcol % p_ts) + total) / p_ts; /* number of tabs */
+	    i = ((ws_vcol % ts_val) + total) / ts_val; /* number of tabs */
 	if (i)
-	    j = ((ws_vcol % p_ts) + total) % p_ts; /* number of spp */
+	    j = ((ws_vcol % ts_val) + total) % ts_val; /* number of spp */
 	else
 	    j = total;
 #endif
@@ -567,7 +565,7 @@
     int			b_insert,
     struct block_def	*bdp)
 {
-    int		p_ts;
+    int		ts_val;
     int		count = 0;	/* extra spaces to replace a cut TAB */
     int		spaces = 0;	/* non-zero if cutting a TAB */
     colnr_T	offset;		/* pointer along new line */
@@ -589,20 +587,20 @@
 
 	if (b_insert)
 	{
-	    p_ts = bdp->start_char_vcols;
+	    ts_val = bdp->start_char_vcols;
 	    spaces = bdp->startspaces;
 	    if (spaces != 0)
-		count = p_ts - 1; /* we're cutting a TAB */
+		count = ts_val - 1; /* we're cutting a TAB */
 	    offset = bdp->textcol;
 	}
 	else /* append */
 	{
-	    p_ts = bdp->end_char_vcols;
+	    ts_val = bdp->end_char_vcols;
 	    if (!bdp->is_short) /* spaces = padding after block */
 	    {
-		spaces = (bdp->endspaces ? p_ts - bdp->endspaces : 0);
+		spaces = (bdp->endspaces ? ts_val - bdp->endspaces : 0);
 		if (spaces != 0)
-		    count = p_ts - 1; /* we're cutting a TAB */
+		    count = ts_val - 1; /* we're cutting a TAB */
 		offset = bdp->textcol + bdp->textlen - (spaces != 0);
 	    }
 	    else /* spaces = padding to block edge */
@@ -651,7 +649,7 @@
 	if (spaces && !bdp->is_short)
 	{
 	    /* insert post-padding */
-	    vim_memset(newp + offset + spaces, ' ', (size_t)(p_ts - spaces));
+	    vim_memset(newp + offset + spaces, ' ', (size_t)(ts_val - spaces));
 	    /* We're splitting a TAB, don't copy it. */
 	    oldp++;
 	    /* We allowed for that TAB, remember this now */
@@ -5591,10 +5589,10 @@
     pos_T	startpos;
     pos_T	endpos;
 
-    dohex = (vim_strchr(curbuf->b_p_nf, 'x') != NULL);	/* "heX" */
-    dooct = (vim_strchr(curbuf->b_p_nf, 'o') != NULL);	/* "Octal" */
-    dobin = (vim_strchr(curbuf->b_p_nf, 'b') != NULL);	/* "Bin" */
-    doalp = (vim_strchr(curbuf->b_p_nf, 'p') != NULL);	/* "alPha" */
+    dohex = (vim_strchr(curbuf->b_p_nf, 'x') != NULL);	// "heX"
+    dooct = (vim_strchr(curbuf->b_p_nf, 'o') != NULL);	// "Octal"
+    dobin = (vim_strchr(curbuf->b_p_nf, 'b') != NULL);	// "Bin"
+    doalp = (vim_strchr(curbuf->b_p_nf, 'p') != NULL);	// "alPha"
 
     curwin->w_cursor = *pos;
     ptr = ml_get(pos->lnum);
diff --git a/src/option.c b/src/option.c
index 99e046f..1ffa11d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -38,31 +38,16 @@
 static void set_options_default(int opt_flags);
 static void set_string_default_esc(char *name, char_u *val, int escape);
 static char_u *term_bg_default(void);
-static void did_set_option(int opt_idx, int opt_flags, int new_value, int value_checked);
 static char_u *option_expand(int opt_idx, char_u *val);
 static void didset_options(void);
 static void didset_options2(void);
-static void check_string_option(char_u **pp);
 #if defined(FEAT_EVAL) || defined(PROTO)
 static long_u *insecure_flag(int opt_idx, int opt_flags);
 #else
 # define insecure_flag(opt_idx, opt_flags) (&options[opt_idx].flags)
 #endif
-static void set_string_option_global(int opt_idx, char_u **varp);
-static char *did_set_string_option(int opt_idx, char_u **varp, int new_value_alloced, char_u *oldval, char *errbuf, int opt_flags, int *value_checked);
-#ifdef FEAT_STL_OPT
-static char *check_stl_option(char_u *s);
-#endif
-#ifdef FEAT_CLIPBOARD
-static char *check_clipboard_option(void);
-#endif
-#ifdef FEAT_EVAL
-static void set_option_sctx_idx(int opt_idx, int opt_flags, sctx_T script_ctx);
-#endif
 static char *set_bool_option(int opt_idx, char_u *varp, int value, int opt_flags);
 static char *set_num_option(int opt_idx, char_u *varp, long value, char *errbuf, size_t errbuflen, int opt_flags);
-static void check_redraw(long_u flags);
-static int findoption(char_u *);
 static int find_key_option(char_u *arg_arg, int has_lt);
 static void showoptions(int all, int opt_flags);
 static int optval_default(struct vimoption *, char_u *varp, int compatible);
@@ -70,7 +55,7 @@
 static int put_setstring(FILE *fd, char *cmd, char *name, char_u **valuep, long_u flags);
 static int put_setnum(FILE *fd, char *cmd, char *name, long *valuep);
 static int put_setbool(FILE *fd, char *cmd, char *name, int value);
-static int  istermoption(struct vimoption *);
+static int istermoption(struct vimoption *p);
 static char_u *get_varp_scope(struct vimoption *p, int opt_flags);
 static char_u *get_varp(struct vimoption *);
 static void check_win_options(win_T *win);
@@ -79,18 +64,6 @@
 static int wc_use_keyname(char_u *varp, long *wcp);
 static void paste_option_changed(void);
 static void compatible_set(void);
-#ifdef FEAT_LINEBREAK
-static void fill_breakat_flags(void);
-#endif
-static int opt_strings_flags(char_u *val, char **values, unsigned *flagp, int list);
-static int check_opt_strings(char_u *val, char **values, int);
-static int check_opt_wim(void);
-#ifdef FEAT_LINEBREAK
-static int briopt_check(win_T *wp);
-#endif
-#ifdef FEAT_SYN_HL
-static int fill_culopt_flags(char_u *val, win_T *wp);
-#endif
 
 /*
  * Initialize the options, first part.
@@ -356,7 +329,7 @@
      * Don't set the P_ALLOCED flag, because we don't want to free the
      * default.
      */
-    for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
+    for (opt_idx = 0; !istermoption_idx(opt_idx); opt_idx++)
     {
 	if ((options[opt_idx].flags & P_GETTEXT)
 					      && options[opt_idx].var != NULL)
@@ -622,7 +595,7 @@
     win_T	*wp;
     tabpage_T	*tp;
 
-    for (i = 0; !istermoption(&options[i]); i++)
+    for (i = 0; !istermoption_idx(i); i++)
 	if (!(options[i].flags & P_NODEFAULT)
 		&& (opt_flags == 0
 		    || (options[i].var != (char_u *)&p_enc
@@ -704,7 +677,7 @@
     curbuf = curwin->w_buffer;
     block_autocmds();
 
-    for (i = 0; !istermoption(&options[i]); i++)
+    for (i = 0; !istermoption_idx(i); i++)
     {
 	struct vimoption    *p = &(options[i]);
 	char_u		    *varp = get_varp_scope(p, OPT_LOCAL);
@@ -730,7 +703,7 @@
 {
     int		i;
 
-    for (i = 0; !istermoption(&options[i]); i++)
+    for (i = 0; !istermoption_idx(i); i++)
     {
 	if (options[i].indir == PV_NONE)
 	{
@@ -1133,66 +1106,6 @@
 }
 #endif
 
-#if defined(FEAT_EVAL)
-/*
- * Trigger the OptionSet autocommand.
- * "opt_idx"	is the index of the option being set.
- * "opt_flags"	can be OPT_LOCAL etc.
- * "oldval"	the old value
- *  "oldval_l"  the old local value (only non-NULL if global and local value
- *		are set)
- * "oldval_g"   the old global value (only non-NULL if global and local value
- *		are set)
- * "newval"	the new value
- */
-    static void
-trigger_optionsset_string(
-	int	opt_idx,
-	int	opt_flags,
-	char_u  *oldval,
-	char_u  *oldval_l,
-	char_u  *oldval_g,
-	char_u  *newval)
-{
-    // Don't do this recursively.
-    if (oldval != NULL && newval != NULL
-				    && *get_vim_var_str(VV_OPTION_TYPE) == NUL)
-    {
-	char_u buf_type[7];
-
-	sprintf((char *)buf_type, "%s",
-	    (opt_flags & OPT_LOCAL) ? "local" : "global");
-	set_vim_var_string(VV_OPTION_OLD, oldval, -1);
-	set_vim_var_string(VV_OPTION_NEW, newval, -1);
-	set_vim_var_string(VV_OPTION_TYPE, buf_type, -1);
-	if (opt_flags & OPT_LOCAL)
-	{
-	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"setlocal", -1);
-	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval, -1);
-	}
-	if (opt_flags & OPT_GLOBAL)
-	{
-	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"setglobal", -1);
-	    set_vim_var_string(VV_OPTION_OLDGLOBAL, oldval, -1);
-	}
-	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
-	{
-	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"set", -1);
-	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval_l, -1);
-	    set_vim_var_string(VV_OPTION_OLDGLOBAL, oldval_g, -1);
-	}
-	if (opt_flags & OPT_MODELINE)
-	{
-	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"modeline", -1);
-	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval, -1);
-	}
-	apply_autocmds(EVENT_OPTIONSET,
-		       (char_u *)options[opt_idx].fullname, NULL, FALSE, NULL);
-	reset_v_option_vars();
-    }
-}
-#endif
-
 /*
  * Parse 'arg' for option settings.
  *
@@ -2199,7 +2112,7 @@
  * Call this when an option has been given a new value through a user command.
  * Sets the P_WAS_SET flag and takes care of the P_INSECURE flag.
  */
-    static void
+    void
 did_set_option(
     int	    opt_idx,
     int	    opt_flags,	    // possibly with OPT_MODELINE
@@ -2225,16 +2138,6 @@
 	*p = *p & ~P_INSECURE;
 }
 
-    static char *
-illegal_char(char *errbuf, int c)
-{
-    if (errbuf == NULL)
-	return "";
-    sprintf((char *)errbuf, _("E539: Illegal character <%s>"),
-							(char *)transchar(c));
-    return errbuf;
-}
-
 /*
  * Convert a key name or string into a key value.
  * Used for 'wildchar' and 'cedit' options.
@@ -2252,12 +2155,12 @@
     return *arg;
 }
 
-#ifdef FEAT_CMDWIN
+#if defined(FEAT_CMDWIN) || defined(PROTO)
 /*
  * Check value of 'cedit' and set cedit_key.
  * Returns NULL if value is OK, error message otherwise.
  */
-    static char *
+    char *
 check_cedit(void)
 {
     int n;
@@ -2282,7 +2185,7 @@
  * When switching the title or icon off, call mch_restore_title() to get
  * the old value back.
  */
-    static void
+    void
 did_set_title(void)
 {
     if (starting != NO_SCREEN
@@ -2411,34 +2314,14 @@
     /* initialize the table for 'iskeyword' et.al. */
     (void)init_chartab();
 
-    (void)opt_strings_flags(p_cmp, p_cmp_values, &cmp_flags, TRUE);
-    (void)opt_strings_flags(p_bkc, p_bkc_values, &bkc_flags, TRUE);
-    (void)opt_strings_flags(p_bo, p_bo_values, &bo_flags, TRUE);
-#ifdef FEAT_SESSION
-    (void)opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, TRUE);
-    (void)opt_strings_flags(p_vop, p_ssop_values, &vop_flags, TRUE);
-#endif
-#ifdef FEAT_FOLDING
-    (void)opt_strings_flags(p_fdo, p_fdo_values, &fdo_flags, TRUE);
-#endif
-    (void)opt_strings_flags(p_dy, p_dy_values, &dy_flags, TRUE);
-    (void)opt_strings_flags(p_tc, p_tc_values, &tc_flags, FALSE);
-    (void)opt_strings_flags(p_ve, p_ve_values, &ve_flags, TRUE);
-#if defined(FEAT_MOUSE) && (defined(UNIX) || defined(VMS))
-    (void)opt_strings_flags(p_ttym, p_ttym_values, &ttym_flags, FALSE);
-#endif
+    didset_string_options();
+
 #ifdef FEAT_SPELL
     (void)spell_check_msm();
     (void)spell_check_sps();
     (void)compile_cap_prog(curwin->w_s);
     (void)did_set_spell_option(TRUE);
 #endif
-#if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
-    (void)opt_strings_flags(p_toolbar, p_toolbar_values, &toolbar_flags, TRUE);
-#endif
-#if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
-    (void)opt_strings_flags(p_tbis, p_tbis_values, &tbis_flags, FALSE);
-#endif
 #ifdef FEAT_CMDWIN
     /* set cedit_key */
     (void)check_cedit();
@@ -2497,138 +2380,6 @@
 }
 
 /*
- * Check string options in a buffer for NULL value.
- */
-    void
-check_buf_options(buf_T *buf)
-{
-    check_string_option(&buf->b_p_bh);
-    check_string_option(&buf->b_p_bt);
-    check_string_option(&buf->b_p_fenc);
-    check_string_option(&buf->b_p_ff);
-#ifdef FEAT_FIND_ID
-    check_string_option(&buf->b_p_def);
-    check_string_option(&buf->b_p_inc);
-# ifdef FEAT_EVAL
-    check_string_option(&buf->b_p_inex);
-# endif
-#endif
-#if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
-    check_string_option(&buf->b_p_inde);
-    check_string_option(&buf->b_p_indk);
-#endif
-#if defined(FEAT_BEVAL) && defined(FEAT_EVAL)
-    check_string_option(&buf->b_p_bexpr);
-#endif
-#if defined(FEAT_CRYPT)
-    check_string_option(&buf->b_p_cm);
-#endif
-    check_string_option(&buf->b_p_fp);
-#if defined(FEAT_EVAL)
-    check_string_option(&buf->b_p_fex);
-#endif
-#ifdef FEAT_CRYPT
-    check_string_option(&buf->b_p_key);
-#endif
-    check_string_option(&buf->b_p_kp);
-    check_string_option(&buf->b_p_mps);
-    check_string_option(&buf->b_p_fo);
-    check_string_option(&buf->b_p_flp);
-    check_string_option(&buf->b_p_isk);
-#ifdef FEAT_COMMENTS
-    check_string_option(&buf->b_p_com);
-#endif
-#ifdef FEAT_FOLDING
-    check_string_option(&buf->b_p_cms);
-#endif
-    check_string_option(&buf->b_p_nf);
-#ifdef FEAT_TEXTOBJ
-    check_string_option(&buf->b_p_qe);
-#endif
-#ifdef FEAT_SYN_HL
-    check_string_option(&buf->b_p_syn);
-    check_string_option(&buf->b_s.b_syn_isk);
-#endif
-#ifdef FEAT_SPELL
-    check_string_option(&buf->b_s.b_p_spc);
-    check_string_option(&buf->b_s.b_p_spf);
-    check_string_option(&buf->b_s.b_p_spl);
-#endif
-#ifdef FEAT_SEARCHPATH
-    check_string_option(&buf->b_p_sua);
-#endif
-#ifdef FEAT_CINDENT
-    check_string_option(&buf->b_p_cink);
-    check_string_option(&buf->b_p_cino);
-    parse_cino(buf);
-#endif
-    check_string_option(&buf->b_p_ft);
-#if defined(FEAT_SMARTINDENT) || defined(FEAT_CINDENT)
-    check_string_option(&buf->b_p_cinw);
-#endif
-    check_string_option(&buf->b_p_cpt);
-#ifdef FEAT_COMPL_FUNC
-    check_string_option(&buf->b_p_cfu);
-    check_string_option(&buf->b_p_ofu);
-#endif
-#ifdef FEAT_EVAL
-    check_string_option(&buf->b_p_tfu);
-#endif
-#ifdef FEAT_KEYMAP
-    check_string_option(&buf->b_p_keymap);
-#endif
-#ifdef FEAT_QUICKFIX
-    check_string_option(&buf->b_p_gp);
-    check_string_option(&buf->b_p_mp);
-    check_string_option(&buf->b_p_efm);
-#endif
-    check_string_option(&buf->b_p_ep);
-    check_string_option(&buf->b_p_path);
-    check_string_option(&buf->b_p_tags);
-    check_string_option(&buf->b_p_tc);
-    check_string_option(&buf->b_p_dict);
-    check_string_option(&buf->b_p_tsr);
-#ifdef FEAT_LISP
-    check_string_option(&buf->b_p_lw);
-#endif
-    check_string_option(&buf->b_p_bkc);
-    check_string_option(&buf->b_p_menc);
-#ifdef FEAT_VARTABS
-    check_string_option(&buf->b_p_vsts);
-    check_string_option(&buf->b_p_vts);
-#endif
-}
-
-/*
- * Free the string allocated for an option.
- * Checks for the string being empty_option. This may happen if we're out of
- * memory, vim_strsave() returned NULL, which was replaced by empty_option by
- * check_options().
- * Does NOT check for P_ALLOCED flag!
- */
-    void
-free_string_option(char_u *p)
-{
-    if (p != empty_option)
-	vim_free(p);
-}
-
-    void
-clear_string_option(char_u **pp)
-{
-    if (*pp != empty_option)
-	vim_free(*pp);
-    *pp = empty_option;
-}
-
-    static void
-check_string_option(char_u **pp)
-{
-    if (*pp == NULL)
-	*pp = empty_option;
-}
-
-/*
  * Return the option index found by a pointer into term_strings[].
  * Return -1 if not found.
  */
@@ -2714,11 +2465,11 @@
 }
 #endif
 
-#ifdef FEAT_TITLE
+#if defined(FEAT_TITLE) || defined(PROTO)
 /*
  * Redraw the window title and/or tab page text later.
  */
-static void redraw_titles(void)
+void redraw_titles(void)
 {
     need_maketitle = TRUE;
     redraw_tabline = TRUE;
@@ -2726,237 +2477,6 @@
 #endif
 
 /*
- * Set a string option to a new value (without checking the effect).
- * The string is copied into allocated memory.
- * if ("opt_idx" == -1) "name" is used, otherwise "opt_idx" is used.
- * When "set_sid" is zero set the scriptID to current_sctx.sc_sid.  When
- * "set_sid" is SID_NONE don't set the scriptID.  Otherwise set the scriptID to
- * "set_sid".
- */
-    void
-set_string_option_direct(
-    char_u	*name,
-    int		opt_idx,
-    char_u	*val,
-    int		opt_flags,	/* OPT_FREE, OPT_LOCAL and/or OPT_GLOBAL */
-    int		set_sid UNUSED)
-{
-    char_u	*s;
-    char_u	**varp;
-    int		both = (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0;
-    int		idx = opt_idx;
-
-    if (idx == -1)		/* use name */
-    {
-	idx = findoption(name);
-	if (idx < 0)	/* not found (should not happen) */
-	{
-	    semsg(_(e_intern2), "set_string_option_direct()");
-	    siemsg(_("For option %s"), name);
-	    return;
-	}
-    }
-
-    if (options[idx].var == NULL)	/* can't set hidden option */
-	return;
-
-    s = vim_strsave(val);
-    if (s != NULL)
-    {
-	varp = (char_u **)get_varp_scope(&(options[idx]),
-					       both ? OPT_LOCAL : opt_flags);
-	if ((opt_flags & OPT_FREE) && (options[idx].flags & P_ALLOCED))
-	    free_string_option(*varp);
-	*varp = s;
-
-	/* For buffer/window local option may also set the global value. */
-	if (both)
-	    set_string_option_global(idx, varp);
-
-	options[idx].flags |= P_ALLOCED;
-
-	/* When setting both values of a global option with a local value,
-	 * make the local value empty, so that the global value is used. */
-	if (((int)options[idx].indir & PV_BOTH) && both)
-	{
-	    free_string_option(*varp);
-	    *varp = empty_option;
-	}
-# ifdef FEAT_EVAL
-	if (set_sid != SID_NONE)
-	{
-	    sctx_T script_ctx;
-
-	    if (set_sid == 0)
-		script_ctx = current_sctx;
-	    else
-	    {
-		script_ctx.sc_sid = set_sid;
-		script_ctx.sc_seq = 0;
-		script_ctx.sc_lnum = 0;
-		script_ctx.sc_version = 1;
-	    }
-	    set_option_sctx_idx(idx, opt_flags, script_ctx);
-	}
-# endif
-    }
-}
-
-/*
- * Like set_string_option_direct(), but for a window-local option in "wp".
- * Blocks autocommands to avoid the old curwin becoming invalid.
- */
-    void
-set_string_option_direct_in_win(
-	win_T		*wp,
-	char_u		*name,
-	int		opt_idx,
-	char_u		*val,
-	int		opt_flags,
-	int		set_sid)
-{
-    win_T	*save_curwin = curwin;
-
-    block_autocmds();
-    curwin = wp;
-    curbuf = curwin->w_buffer;
-    set_string_option_direct(name, opt_idx, val, opt_flags, set_sid);
-    curwin = save_curwin;
-    curbuf = curwin->w_buffer;
-    unblock_autocmds();
-}
-
-/*
- * Like set_string_option_direct(), but for a buffer-local option in "buf".
- * Blocks autocommands to avoid the old curbuf becoming invalid.
- */
-    void
-set_string_option_direct_in_buf(
-	buf_T		*buf,
-	char_u		*name,
-	int		opt_idx,
-	char_u		*val,
-	int		opt_flags,
-	int		set_sid)
-{
-    buf_T	*save_curbuf = curbuf;
-
-    block_autocmds();
-    curbuf = buf;
-    curwin->w_buffer = curbuf;
-    set_string_option_direct(name, opt_idx, val, opt_flags, set_sid);
-    curbuf = save_curbuf;
-    curwin->w_buffer = curbuf;
-    unblock_autocmds();
-}
-
-/*
- * Set global value for string option when it's a local option.
- */
-    static void
-set_string_option_global(
-    int		opt_idx,	/* option index */
-    char_u	**varp)		/* pointer to option variable */
-{
-    char_u	**p, *s;
-
-    /* the global value is always allocated */
-    if (options[opt_idx].var == VAR_WIN)
-	p = (char_u **)GLOBAL_WO(varp);
-    else
-	p = (char_u **)options[opt_idx].var;
-    if (options[opt_idx].indir != PV_NONE
-	    && p != varp
-	    && (s = vim_strsave(*varp)) != NULL)
-    {
-	free_string_option(*p);
-	*p = s;
-    }
-}
-
-/*
- * Set a string option to a new value, and handle the effects.
- *
- * Returns NULL on success or error message on error.
- */
-    static char *
-set_string_option(
-    int		opt_idx,
-    char_u	*value,
-    int		opt_flags)	/* OPT_LOCAL and/or OPT_GLOBAL */
-{
-    char_u	*s;
-    char_u	**varp;
-    char_u	*oldval;
-#if defined(FEAT_EVAL)
-    char_u	*oldval_l = NULL;
-    char_u	*oldval_g = NULL;
-    char_u	*saved_oldval = NULL;
-    char_u	*saved_oldval_l = NULL;
-    char_u	*saved_oldval_g = NULL;
-    char_u	*saved_newval = NULL;
-#endif
-    char	*r = NULL;
-    int		value_checked = FALSE;
-
-    if (options[opt_idx].var == NULL)	/* don't set hidden option */
-	return NULL;
-
-    s = vim_strsave(value);
-    if (s != NULL)
-    {
-	varp = (char_u **)get_varp_scope(&(options[opt_idx]),
-		(opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
-		    ? (((int)options[opt_idx].indir & PV_BOTH)
-			? OPT_GLOBAL : OPT_LOCAL)
-		    : opt_flags);
-	oldval = *varp;
-#if defined(FEAT_EVAL)
-	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
-	{
-	    oldval_l = *(char_u **)get_varp_scope(&(options[opt_idx]),
-								    OPT_LOCAL);
-	    oldval_g = *(char_u **)get_varp_scope(&(options[opt_idx]),
-								   OPT_GLOBAL);
-	}
-#endif
-	*varp = s;
-
-#if defined(FEAT_EVAL)
-	if (!starting
-# ifdef FEAT_CRYPT
-		&& options[opt_idx].indir != PV_KEY
-# endif
-		)
-	{
-	    if (oldval_l != NULL)
-		saved_oldval_l = vim_strsave(oldval_l);
-	    if (oldval_g != NULL)
-		saved_oldval_g = vim_strsave(oldval_g);
-	    saved_oldval = vim_strsave(oldval);
-	    saved_newval = vim_strsave(s);
-	}
-#endif
-	if ((r = did_set_string_option(opt_idx, varp, TRUE, oldval, NULL,
-					   opt_flags, &value_checked)) == NULL)
-	    did_set_option(opt_idx, opt_flags, TRUE, value_checked);
-
-#if defined(FEAT_EVAL)
-	/* call autocommand after handling side effects */
-	if (r == NULL)
-	    trigger_optionsset_string(opt_idx, opt_flags,
-				   saved_oldval, saved_oldval_l,
-				   saved_oldval_g, saved_newval);
-	vim_free(saved_oldval);
-	vim_free(saved_oldval_l);
-	vim_free(saved_oldval_g);
-	vim_free(saved_newval);
-#endif
-    }
-    return r;
-}
-
-/*
  * Return TRUE if "val" is a valid name: only consists of alphanumeric ASCII
  * characters or characters in "allowed".
  */
@@ -2971,1898 +2491,12 @@
     return TRUE;
 }
 
-/*
- * Return TRUE if "val" is a valid 'filetype' name.
- * Also used for 'syntax' and 'keymap'.
- */
-    static int
-valid_filetype(char_u *val)
-{
-    return valid_name(val, ".-_");
-}
-
-/*
- * Handle string options that need some action to perform when changed.
- * Returns NULL for success, or an error message for an error.
- */
-    static char *
-did_set_string_option(
-    int		opt_idx,		// index in options[] table
-    char_u	**varp,			// pointer to the option variable
-    int		new_value_alloced,	// new value was allocated
-    char_u	*oldval,		// previous value of the option
-    char	*errbuf,		// buffer for errors, or NULL
-    int		opt_flags,		// OPT_LOCAL and/or OPT_GLOBAL
-    int		*value_checked)		// value was checked to be save, no
-					// need to set P_INSECURE
-{
-    char	*errmsg = NULL;
-    char_u	*s, *p;
-    int		did_chartab = FALSE;
-    char_u	**gvarp;
-    long_u	free_oldval = (options[opt_idx].flags & P_ALLOCED);
-#ifdef FEAT_GUI
-    /* set when changing an option that only requires a redraw in the GUI */
-    int		redraw_gui_only = FALSE;
-#endif
-    int		value_changed = FALSE;
-#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-    int		did_swaptcap = FALSE;
-#endif
-
-    /* Get the global option to compare with, otherwise we would have to check
-     * two values for all local options. */
-    gvarp = (char_u **)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL);
-
-    /* Disallow changing some options from secure mode */
-    if ((secure
-#ifdef HAVE_SANDBOX
-		|| sandbox != 0
-#endif
-		) && (options[opt_idx].flags & P_SECURE))
-	errmsg = e_secure;
-
-    // Check for a "normal" directory or file name in some options.  Disallow a
-    // path separator (slash and/or backslash), wildcards and characters that
-    // are often illegal in a file name. Be more permissive if "secure" is off.
-    else if (((options[opt_idx].flags & P_NFNAME)
-		    && vim_strpbrk(*varp, (char_u *)(secure
-			    ? "/\\*?[|;&<>\r\n" : "/\\*?[<>\r\n")) != NULL)
-	  || ((options[opt_idx].flags & P_NDNAME)
-		    && vim_strpbrk(*varp, (char_u *)"*?[|;&<>\r\n") != NULL))
-	errmsg = e_invarg;
-
-    /* 'term' */
-    else if (varp == &T_NAME)
-    {
-	if (T_NAME[0] == NUL)
-	    errmsg = N_("E529: Cannot set 'term' to empty string");
-#ifdef FEAT_GUI
-	if (gui.in_use)
-	    errmsg = N_("E530: Cannot change term in GUI");
-	else if (term_is_gui(T_NAME))
-	    errmsg = N_("E531: Use \":gui\" to start the GUI");
-#endif
-	else if (set_termname(T_NAME) == FAIL)
-	    errmsg = N_("E522: Not found in termcap");
-	else
-	{
-	    /* Screen colors may have changed. */
-	    redraw_later_clear();
-
-	    /* Both 'term' and 'ttytype' point to T_NAME, only set the
-	     * P_ALLOCED flag on 'term'. */
-	    opt_idx = findoption((char_u *)"term");
-	    free_oldval = (options[opt_idx].flags & P_ALLOCED);
-	}
-    }
-
-    /* 'backupcopy' */
-    else if (gvarp == &p_bkc)
-    {
-	char_u		*bkc = p_bkc;
-	unsigned int	*flags = &bkc_flags;
-
-	if (opt_flags & OPT_LOCAL)
-	{
-	    bkc = curbuf->b_p_bkc;
-	    flags = &curbuf->b_bkc_flags;
-	}
-
-	if ((opt_flags & OPT_LOCAL) && *bkc == NUL)
-	    /* make the local value empty: use the global value */
-	    *flags = 0;
-	else
-	{
-	    if (opt_strings_flags(bkc, p_bkc_values, flags, TRUE) != OK)
-		errmsg = e_invarg;
-	    if ((((int)*flags & BKC_AUTO) != 0)
-		    + (((int)*flags & BKC_YES) != 0)
-		    + (((int)*flags & BKC_NO) != 0) != 1)
-	    {
-		/* Must have exactly one of "auto", "yes"  and "no". */
-		(void)opt_strings_flags(oldval, p_bkc_values, flags, TRUE);
-		errmsg = e_invarg;
-	    }
-	}
-    }
-
-    /* 'backupext' and 'patchmode' */
-    else if (varp == &p_bex || varp == &p_pm)
-    {
-	if (STRCMP(*p_bex == '.' ? p_bex + 1 : p_bex,
-		     *p_pm == '.' ? p_pm + 1 : p_pm) == 0)
-	    errmsg = N_("E589: 'backupext' and 'patchmode' are equal");
-    }
-#ifdef FEAT_LINEBREAK
-    /* 'breakindentopt' */
-    else if (varp == &curwin->w_p_briopt)
-    {
-	if (briopt_check(curwin) == FAIL)
-	    errmsg = e_invarg;
-    }
-#endif
-
-    /*
-     * 'isident', 'iskeyword', 'isprint or 'isfname' option: refill g_chartab[]
-     * If the new option is invalid, use old value.  'lisp' option: refill
-     * g_chartab[] for '-' char
-     */
-    else if (  varp == &p_isi
-	    || varp == &(curbuf->b_p_isk)
-	    || varp == &p_isp
-	    || varp == &p_isf)
-    {
-	if (init_chartab() == FAIL)
-	{
-	    did_chartab = TRUE;	    /* need to restore it below */
-	    errmsg = e_invarg;	    /* error in value */
-	}
-    }
-
-    /* 'helpfile' */
-    else if (varp == &p_hf)
-    {
-	/* May compute new values for $VIM and $VIMRUNTIME */
-	if (didset_vim)
-	{
-	    vim_setenv((char_u *)"VIM", (char_u *)"");
-	    didset_vim = FALSE;
-	}
-	if (didset_vimruntime)
-	{
-	    vim_setenv((char_u *)"VIMRUNTIME", (char_u *)"");
-	    didset_vimruntime = FALSE;
-	}
-    }
-
-#ifdef FEAT_SYN_HL
-    /* 'cursorlineopt' */
-    else if (varp == &curwin->w_p_culopt
-				  || gvarp == &curwin->w_allbuf_opt.wo_culopt)
-    {
-	if (**varp == NUL || fill_culopt_flags(*varp, curwin) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'colorcolumn' */
-    else if (varp == &curwin->w_p_cc)
-	errmsg = check_colorcolumn(curwin);
-#endif
-
-#ifdef FEAT_MULTI_LANG
-    /* 'helplang' */
-    else if (varp == &p_hlg)
-    {
-	/* Check for "", "ab", "ab,cd", etc. */
-	for (s = p_hlg; *s != NUL; s += 3)
-	{
-	    if (s[1] == NUL || ((s[2] != ',' || s[3] == NUL) && s[2] != NUL))
-	    {
-		errmsg = e_invarg;
-		break;
-	    }
-	    if (s[2] == NUL)
-		break;
-	}
-    }
-#endif
-
-    /* 'highlight' */
-    else if (varp == &p_hl)
-    {
-	if (highlight_changed() == FAIL)
-	    errmsg = e_invarg;	/* invalid flags */
-    }
-
-    /* 'nrformats' */
-    else if (gvarp == &p_nf)
-    {
-	if (check_opt_strings(*varp, p_nf_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_SESSION
-    /* 'sessionoptions' */
-    else if (varp == &p_ssop)
-    {
-	if (opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-	if ((ssop_flags & SSOP_CURDIR) && (ssop_flags & SSOP_SESDIR))
-	{
-	    /* Don't allow both "sesdir" and "curdir". */
-	    (void)opt_strings_flags(oldval, p_ssop_values, &ssop_flags, TRUE);
-	    errmsg = e_invarg;
-	}
-    }
-    /* 'viewoptions' */
-    else if (varp == &p_vop)
-    {
-	if (opt_strings_flags(p_vop, p_ssop_values, &vop_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-#endif
-
-    /* 'scrollopt' */
-    else if (varp == &p_sbo)
-    {
-	if (check_opt_strings(p_sbo, p_scbopt_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'ambiwidth' */
-    else if (varp == &p_ambw || varp == &p_emoji)
-    {
-	if (check_opt_strings(p_ambw, p_ambw_values, FALSE) != OK)
-	    errmsg = e_invarg;
-	else if (set_chars_option(&p_lcs) != NULL)
-	    errmsg = _("E834: Conflicts with value of 'listchars'");
-	else if (set_chars_option(&p_fcs) != NULL)
-	    errmsg = _("E835: Conflicts with value of 'fillchars'");
-    }
-
-    /* 'background' */
-    else if (varp == &p_bg)
-    {
-	if (check_opt_strings(p_bg, p_bg_values, FALSE) == OK)
-	{
-#ifdef FEAT_EVAL
-	    int dark = (*p_bg == 'd');
-#endif
-
-	    init_highlight(FALSE, FALSE);
-
-#ifdef FEAT_EVAL
-	    if (dark != (*p_bg == 'd')
-			  && get_var_value((char_u *)"g:colors_name") != NULL)
-	    {
-		/* The color scheme must have set 'background' back to another
-		 * value, that's not what we want here.  Disable the color
-		 * scheme and set the colors again. */
-		do_unlet((char_u *)"g:colors_name", TRUE);
-		free_string_option(p_bg);
-		p_bg = vim_strsave((char_u *)(dark ? "dark" : "light"));
-		check_string_option(&p_bg);
-		init_highlight(FALSE, FALSE);
-	    }
-#endif
-	}
-	else
-	    errmsg = e_invarg;
-    }
-
-    /* 'wildmode' */
-    else if (varp == &p_wim)
-    {
-	if (check_opt_wim() == FAIL)
-	    errmsg = e_invarg;
-    }
-
-    /* 'wildoptions' */
-    else if (varp == &p_wop)
-    {
-	if (check_opt_strings(p_wop, p_wop_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_WAK
-    /* 'winaltkeys' */
-    else if (varp == &p_wak)
-    {
-	if (*p_wak == NUL
-		|| check_opt_strings(p_wak, p_wak_values, FALSE) != OK)
-	    errmsg = e_invarg;
-# ifdef FEAT_MENU
-#  ifdef FEAT_GUI_MOTIF
-	else if (gui.in_use)
-	    gui_motif_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
-#  else
-#   ifdef FEAT_GUI_GTK
-	else if (gui.in_use)
-	    gui_gtk_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
-#   endif
-#  endif
-# endif
-    }
-#endif
-
-    /* 'eventignore' */
-    else if (varp == &p_ei)
-    {
-	if (check_ei() == FAIL)
-	    errmsg = e_invarg;
-    }
-
-    /* 'encoding', 'fileencoding', 'termencoding' and 'makeencoding' */
-    else if (varp == &p_enc || gvarp == &p_fenc || varp == &p_tenc
-							   || gvarp == &p_menc)
-    {
-	if (gvarp == &p_fenc)
-	{
-	    if (!curbuf->b_p_ma && opt_flags != OPT_GLOBAL)
-		errmsg = e_modifiable;
-	    else if (vim_strchr(*varp, ',') != NULL)
-		/* No comma allowed in 'fileencoding'; catches confusing it
-		 * with 'fileencodings'. */
-		errmsg = e_invarg;
-	    else
-	    {
-#ifdef FEAT_TITLE
-		/* May show a "+" in the title now. */
-		redraw_titles();
-#endif
-		/* Add 'fileencoding' to the swap file. */
-		ml_setflags(curbuf);
-	    }
-	}
-	if (errmsg == NULL)
-	{
-	    /* canonize the value, so that STRCMP() can be used on it */
-	    p = enc_canonize(*varp);
-	    if (p != NULL)
-	    {
-		vim_free(*varp);
-		*varp = p;
-	    }
-	    if (varp == &p_enc)
-	    {
-		errmsg = mb_init();
-#ifdef FEAT_TITLE
-		redraw_titles();
-#endif
-	    }
-	}
-
-#if defined(FEAT_GUI_GTK)
-	if (errmsg == NULL && varp == &p_tenc && gui.in_use)
-	{
-	    /* GTK+ 2 uses only a single encoding, and that is UTF-8. */
-	    if (STRCMP(p_tenc, "utf-8") != 0)
-		errmsg = N_("E617: Cannot be changed in the GTK+ 2 GUI");
-	}
-#endif
-
-	if (errmsg == NULL)
-	{
-#ifdef FEAT_KEYMAP
-	    /* When 'keymap' is used and 'encoding' changes, reload the keymap
-	     * (with another encoding). */
-	    if (varp == &p_enc && *curbuf->b_p_keymap != NUL)
-		(void)keymap_init();
-#endif
-
-	    /* When 'termencoding' is not empty and 'encoding' changes or when
-	     * 'termencoding' changes, need to setup for keyboard input and
-	     * display output conversion. */
-	    if (((varp == &p_enc && *p_tenc != NUL) || varp == &p_tenc))
-	    {
-		if (convert_setup(&input_conv, p_tenc, p_enc) == FAIL
-			|| convert_setup(&output_conv, p_enc, p_tenc) == FAIL)
-		{
-		    semsg(_("E950: Cannot convert between %s and %s"),
-			    p_tenc, p_enc);
-		    errmsg = e_invarg;
-		}
-	    }
-
-#if defined(MSWIN)
-	    /* $HOME may have characters in active code page. */
-	    if (varp == &p_enc)
-		init_homedir();
-#endif
-	}
-    }
-
-#if defined(FEAT_POSTSCRIPT)
-    else if (varp == &p_penc)
-    {
-	/* Canonize printencoding if VIM standard one */
-	p = enc_canonize(p_penc);
-	if (p != NULL)
-	{
-	    vim_free(p_penc);
-	    p_penc = p;
-	}
-	else
-	{
-	    /* Ensure lower case and '-' for '_' */
-	    for (s = p_penc; *s != NUL; s++)
-	    {
-		if (*s == '_')
-		    *s = '-';
-		else
-		    *s = TOLOWER_ASC(*s);
-	    }
-	}
-    }
-#endif
-
-#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
-    else if (varp == &p_imak)
-    {
-	if (!im_xim_isvalid_imactivate())
-	    errmsg = e_invarg;
-    }
-#endif
-
-#ifdef FEAT_KEYMAP
-    else if (varp == &curbuf->b_p_keymap)
-    {
-	if (!valid_filetype(*varp))
-	    errmsg = e_invarg;
-	else
-	{
-	    int	    secure_save = secure;
-
-	    // Reset the secure flag, since the value of 'keymap' has
-	    // been checked to be safe.
-	    secure = 0;
-
-	    // load or unload key mapping tables
-	    errmsg = keymap_init();
-
-	    secure = secure_save;
-
-	    // Since we check the value, there is no need to set P_INSECURE,
-	    // even when the value comes from a modeline.
-	    *value_checked = TRUE;
-	}
-
-	if (errmsg == NULL)
-	{
-	    if (*curbuf->b_p_keymap != NUL)
-	    {
-		/* Installed a new keymap, switch on using it. */
-		curbuf->b_p_iminsert = B_IMODE_LMAP;
-		if (curbuf->b_p_imsearch != B_IMODE_USE_INSERT)
-		    curbuf->b_p_imsearch = B_IMODE_LMAP;
-	    }
-	    else
-	    {
-		/* Cleared the keymap, may reset 'iminsert' and 'imsearch'. */
-		if (curbuf->b_p_iminsert == B_IMODE_LMAP)
-		    curbuf->b_p_iminsert = B_IMODE_NONE;
-		if (curbuf->b_p_imsearch == B_IMODE_LMAP)
-		    curbuf->b_p_imsearch = B_IMODE_USE_INSERT;
-	    }
-	    if ((opt_flags & OPT_LOCAL) == 0)
-	    {
-		set_iminsert_global();
-		set_imsearch_global();
-	    }
-	    status_redraw_curbuf();
-	}
-    }
-#endif
-
-    /* 'fileformat' */
-    else if (gvarp == &p_ff)
-    {
-	if (!curbuf->b_p_ma && !(opt_flags & OPT_GLOBAL))
-	    errmsg = e_modifiable;
-	else if (check_opt_strings(*varp, p_ff_values, FALSE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    /* may also change 'textmode' */
-	    if (get_fileformat(curbuf) == EOL_DOS)
-		curbuf->b_p_tx = TRUE;
-	    else
-		curbuf->b_p_tx = FALSE;
-#ifdef FEAT_TITLE
-	    redraw_titles();
-#endif
-	    /* update flag in swap file */
-	    ml_setflags(curbuf);
-	    /* Redraw needed when switching to/from "mac": a CR in the text
-	     * will be displayed differently. */
-	    if (get_fileformat(curbuf) == EOL_MAC || *oldval == 'm')
-		redraw_curbuf_later(NOT_VALID);
-	}
-    }
-
-    /* 'fileformats' */
-    else if (varp == &p_ffs)
-    {
-	if (check_opt_strings(p_ffs, p_ff_values, TRUE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    /* also change 'textauto' */
-	    if (*p_ffs == NUL)
-		p_ta = FALSE;
-	    else
-		p_ta = TRUE;
-	}
-    }
-
-#if defined(FEAT_CRYPT)
-    /* 'cryptkey' */
-    else if (gvarp == &p_key)
-    {
-	// Make sure the ":set" command doesn't show the new value in the
-	// history.
-	remove_key_from_history();
-
-	if (STRCMP(curbuf->b_p_key, oldval) != 0)
-	    /* Need to update the swapfile. */
-	    ml_set_crypt_key(curbuf, oldval,
-			      *curbuf->b_p_cm == NUL ? p_cm : curbuf->b_p_cm);
-    }
-
-    else if (gvarp == &p_cm)
-    {
-	if (opt_flags & OPT_LOCAL)
-	    p = curbuf->b_p_cm;
-	else
-	    p = p_cm;
-	if (check_opt_strings(p, p_cm_values, TRUE) != OK)
-	    errmsg = e_invarg;
-	else if (crypt_self_test() == FAIL)
-	    errmsg = e_invarg;
-	else
-	{
-	    /* When setting the global value to empty, make it "zip". */
-	    if (*p_cm == NUL)
-	    {
-		if (new_value_alloced)
-		    free_string_option(p_cm);
-		p_cm = vim_strsave((char_u *)"zip");
-		new_value_alloced = TRUE;
-	    }
-	    /* When using ":set cm=name" the local value is going to be empty.
-	     * Do that here, otherwise the crypt functions will still use the
-	     * local value. */
-	    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
-	    {
-		free_string_option(curbuf->b_p_cm);
-		curbuf->b_p_cm = empty_option;
-	    }
-
-	    /* Need to update the swapfile when the effective method changed.
-	     * Set "s" to the effective old value, "p" to the effective new
-	     * method and compare. */
-	    if ((opt_flags & OPT_LOCAL) && *oldval == NUL)
-		s = p_cm;  /* was previously using the global value */
-	    else
-		s = oldval;
-	    if (*curbuf->b_p_cm == NUL)
-		p = p_cm;  /* is now using the global value */
-	    else
-		p = curbuf->b_p_cm;
-	    if (STRCMP(s, p) != 0)
-		ml_set_crypt_key(curbuf, curbuf->b_p_key, s);
-
-	    /* If the global value changes need to update the swapfile for all
-	     * buffers using that value. */
-	    if ((opt_flags & OPT_GLOBAL) && STRCMP(p_cm, oldval) != 0)
-	    {
-		buf_T	*buf;
-
-		FOR_ALL_BUFFERS(buf)
-		    if (buf != curbuf && *buf->b_p_cm == NUL)
-			ml_set_crypt_key(buf, buf->b_p_key, oldval);
-	    }
-	}
-    }
-#endif
-
-    /* 'matchpairs' */
-    else if (gvarp == &p_mps)
-    {
-	if (has_mbyte)
-	{
-	    for (p = *varp; *p != NUL; ++p)
-	    {
-		int x2 = -1;
-		int x3 = -1;
-
-		if (*p != NUL)
-		    p += mb_ptr2len(p);
-		if (*p != NUL)
-		    x2 = *p++;
-		if (*p != NUL)
-		{
-		    x3 = mb_ptr2char(p);
-		    p += mb_ptr2len(p);
-		}
-		if (x2 != ':' || x3 == -1 || (*p != NUL && *p != ','))
-		{
-		    errmsg = e_invarg;
-		    break;
-		}
-		if (*p == NUL)
-		    break;
-	    }
-	}
-	else
-	{
-	    /* Check for "x:y,x:y" */
-	    for (p = *varp; *p != NUL; p += 4)
-	    {
-		if (p[1] != ':' || p[2] == NUL || (p[3] != NUL && p[3] != ','))
-		{
-		    errmsg = e_invarg;
-		    break;
-		}
-		if (p[3] == NUL)
-		    break;
-	    }
-	}
-    }
-
-#ifdef FEAT_COMMENTS
-    /* 'comments' */
-    else if (gvarp == &p_com)
-    {
-	for (s = *varp; *s; )
-	{
-	    while (*s && *s != ':')
-	    {
-		if (vim_strchr((char_u *)COM_ALL, *s) == NULL
-					     && !VIM_ISDIGIT(*s) && *s != '-')
-		{
-		    errmsg = illegal_char(errbuf, *s);
-		    break;
-		}
-		++s;
-	    }
-	    if (*s++ == NUL)
-		errmsg = N_("E524: Missing colon");
-	    else if (*s == ',' || *s == NUL)
-		errmsg = N_("E525: Zero length string");
-	    if (errmsg != NULL)
-		break;
-	    while (*s && *s != ',')
-	    {
-		if (*s == '\\' && s[1] != NUL)
-		    ++s;
-		++s;
-	    }
-	    s = skip_to_option_part(s);
-	}
-    }
-#endif
-
-    /* 'listchars' */
-    else if (varp == &p_lcs)
-    {
-	errmsg = set_chars_option(varp);
-    }
-
-    /* 'fillchars' */
-    else if (varp == &p_fcs)
-    {
-	errmsg = set_chars_option(varp);
-    }
-
-#ifdef FEAT_CMDWIN
-    /* 'cedit' */
-    else if (varp == &p_cedit)
-    {
-	errmsg = check_cedit();
-    }
-#endif
-
-    /* 'verbosefile' */
-    else if (varp == &p_vfile)
-    {
-	verbose_stop();
-	if (*p_vfile != NUL && verbose_open() == FAIL)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_VIMINFO
-    /* 'viminfo' */
-    else if (varp == &p_viminfo)
-    {
-	for (s = p_viminfo; *s;)
-	{
-	    /* Check it's a valid character */
-	    if (vim_strchr((char_u *)"!\"%'/:<@cfhnrs", *s) == NULL)
-	    {
-		errmsg = illegal_char(errbuf, *s);
-		break;
-	    }
-	    if (*s == 'n')	/* name is always last one */
-		break;
-	    else if (*s == 'r') /* skip until next ',' */
-	    {
-		while (*++s && *s != ',')
-		    ;
-	    }
-	    else if (*s == '%')
-	    {
-		/* optional number */
-		while (vim_isdigit(*++s))
-		    ;
-	    }
-	    else if (*s == '!' || *s == 'h' || *s == 'c')
-		++s;		/* no extra chars */
-	    else		/* must have a number */
-	    {
-		while (vim_isdigit(*++s))
-		    ;
-
-		if (!VIM_ISDIGIT(*(s - 1)))
-		{
-		    if (errbuf != NULL)
-		    {
-			sprintf(errbuf, _("E526: Missing number after <%s>"),
-						    transchar_byte(*(s - 1)));
-			errmsg = errbuf;
-		    }
-		    else
-			errmsg = "";
-		    break;
-		}
-	    }
-	    if (*s == ',')
-		++s;
-	    else if (*s)
-	    {
-		if (errbuf != NULL)
-		    errmsg = N_("E527: Missing comma");
-		else
-		    errmsg = "";
-		break;
-	    }
-	}
-	if (*p_viminfo && errmsg == NULL && get_viminfo_parameter('\'') < 0)
-	    errmsg = N_("E528: Must specify a ' value");
-    }
-#endif /* FEAT_VIMINFO */
-
-    /* terminal options */
-    else if (istermoption(&options[opt_idx]) && full_screen)
-    {
-	/* ":set t_Co=0" and ":set t_Co=1" do ":set t_Co=" */
-	if (varp == &T_CCO)
-	{
-	    int colors = atoi((char *)T_CCO);
-
-	    /* Only reinitialize colors if t_Co value has really changed to
-	     * avoid expensive reload of colorscheme if t_Co is set to the
-	     * same value multiple times. */
-	    if (colors != t_colors)
-	    {
-		t_colors = colors;
-		if (t_colors <= 1)
-		{
-		    if (new_value_alloced)
-			vim_free(T_CCO);
-		    T_CCO = empty_option;
-		}
-#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-		if (is_term_win32())
-		{
-		    swap_tcap();
-		    did_swaptcap = TRUE;
-		}
-#endif
-		/* We now have a different color setup, initialize it again. */
-		init_highlight(TRUE, FALSE);
-	    }
-	}
-	ttest(FALSE);
-	if (varp == &T_ME)
-	{
-	    out_str(T_ME);
-	    redraw_later(CLEAR);
-#if defined(MSWIN) && (!defined(FEAT_GUI_MSWIN) || defined(VIMDLL))
-	    /* Since t_me has been set, this probably means that the user
-	     * wants to use this as default colors.  Need to reset default
-	     * background/foreground colors. */
-# ifdef VIMDLL
-	    if (!gui.in_use && !gui.starting)
-# endif
-		mch_set_normal_colors();
-#endif
-	}
-	if (varp == &T_BE && termcap_active)
-	{
-	    if (*T_BE == NUL)
-		/* When clearing t_BE we assume the user no longer wants
-		 * bracketed paste, thus disable it by writing t_BD. */
-		out_str(T_BD);
-	    else
-		out_str(T_BE);
-	}
-    }
-
-#ifdef FEAT_LINEBREAK
-    /* 'showbreak' */
-    else if (varp == &p_sbr)
-    {
-	for (s = p_sbr; *s; )
-	{
-	    if (ptr2cells(s) != 1)
-		errmsg = N_("E595: contains unprintable or wide character");
-	    MB_PTR_ADV(s);
-	}
-    }
-#endif
-
-#ifdef FEAT_GUI
-    /* 'guifont' */
-    else if (varp == &p_guifont)
-    {
-	if (gui.in_use)
-	{
-	    p = p_guifont;
-# if defined(FEAT_GUI_GTK)
-	    /*
-	     * Put up a font dialog and let the user select a new value.
-	     * If this is cancelled go back to the old value but don't
-	     * give an error message.
-	     */
-	    if (STRCMP(p, "*") == 0)
-	    {
-		p = gui_mch_font_dialog(oldval);
-
-		if (new_value_alloced)
-		    free_string_option(p_guifont);
-
-		p_guifont = (p != NULL) ? p : vim_strsave(oldval);
-		new_value_alloced = TRUE;
-	    }
-# endif
-	    if (p != NULL && gui_init_font(p_guifont, FALSE) != OK)
-	    {
-# if defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_PHOTON)
-		if (STRCMP(p_guifont, "*") == 0)
-		{
-		    /* Dialog was cancelled: Keep the old value without giving
-		     * an error message. */
-		    if (new_value_alloced)
-			free_string_option(p_guifont);
-		    p_guifont = vim_strsave(oldval);
-		    new_value_alloced = TRUE;
-		}
-		else
-# endif
-		    errmsg = N_("E596: Invalid font(s)");
-	    }
-	}
-	redraw_gui_only = TRUE;
-    }
-# ifdef FEAT_XFONTSET
-    else if (varp == &p_guifontset)
-    {
-	if (STRCMP(p_guifontset, "*") == 0)
-	    errmsg = N_("E597: can't select fontset");
-	else if (gui.in_use && gui_init_font(p_guifontset, TRUE) != OK)
-	    errmsg = N_("E598: Invalid fontset");
-	redraw_gui_only = TRUE;
-    }
-# endif
-    else if (varp == &p_guifontwide)
-    {
-	if (STRCMP(p_guifontwide, "*") == 0)
-	    errmsg = N_("E533: can't select wide font");
-	else if (gui_get_wide_font() == FAIL)
-	    errmsg = N_("E534: Invalid wide font");
-	redraw_gui_only = TRUE;
-    }
-#endif
-
-#ifdef CURSOR_SHAPE
-    /* 'guicursor' */
-    else if (varp == &p_guicursor)
-	errmsg = parse_shape_opt(SHAPE_CURSOR);
-#endif
-
-#ifdef FEAT_MOUSESHAPE
-    /* 'mouseshape' */
-    else if (varp == &p_mouseshape)
-    {
-	errmsg = parse_shape_opt(SHAPE_MOUSE);
-	update_mouseshape(-1);
-    }
-#endif
-
-#ifdef FEAT_PRINTER
-    else if (varp == &p_popt)
-	errmsg = parse_printoptions();
-# if defined(FEAT_POSTSCRIPT)
-    else if (varp == &p_pmfn)
-	errmsg = parse_printmbfont();
-# endif
-#endif
-
-#ifdef FEAT_LANGMAP
-    /* 'langmap' */
-    else if (varp == &p_langmap)
-	langmap_set();
-#endif
-
-#ifdef FEAT_LINEBREAK
-    /* 'breakat' */
-    else if (varp == &p_breakat)
-	fill_breakat_flags();
-#endif
-
-#ifdef FEAT_TITLE
-    /* 'titlestring' and 'iconstring' */
-    else if (varp == &p_titlestring || varp == &p_iconstring)
-    {
-# ifdef FEAT_STL_OPT
-	int	flagval = (varp == &p_titlestring) ? STL_IN_TITLE : STL_IN_ICON;
-
-	/* NULL => statusline syntax */
-	if (vim_strchr(*varp, '%') && check_stl_option(*varp) == NULL)
-	    stl_syntax |= flagval;
-	else
-	    stl_syntax &= ~flagval;
-# endif
-	did_set_title();
-    }
-#endif
-
-#ifdef FEAT_GUI
-    /* 'guioptions' */
-    else if (varp == &p_go)
-    {
-	gui_init_which_components(oldval);
-	redraw_gui_only = TRUE;
-    }
-#endif
-
-#if defined(FEAT_GUI_TABLINE)
-    /* 'guitablabel' */
-    else if (varp == &p_gtl)
-    {
-	redraw_tabline = TRUE;
-	redraw_gui_only = TRUE;
-    }
-    /* 'guitabtooltip' */
-    else if (varp == &p_gtt)
-    {
-	redraw_gui_only = TRUE;
-    }
-#endif
-
-#if defined(FEAT_MOUSE_TTY) && (defined(UNIX) || defined(VMS))
-    /* 'ttymouse' */
-    else if (varp == &p_ttym)
-    {
-	/* Switch the mouse off before changing the escape sequences used for
-	 * that. */
-	mch_setmouse(FALSE);
-	if (opt_strings_flags(p_ttym, p_ttym_values, &ttym_flags, FALSE) != OK)
-	    errmsg = e_invarg;
-	else
-	    check_mouse_termcode();
-	if (termcap_active)
-	    setmouse();		/* may switch it on again */
-    }
-#endif
-
-    /* 'selection' */
-    else if (varp == &p_sel)
-    {
-	if (*p_sel == NUL
-		|| check_opt_strings(p_sel, p_sel_values, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'selectmode' */
-    else if (varp == &p_slm)
-    {
-	if (check_opt_strings(p_slm, p_slm_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_BROWSE
-    /* 'browsedir' */
-    else if (varp == &p_bsdir)
-    {
-	if (check_opt_strings(p_bsdir, p_bsdir_values, FALSE) != OK
-		&& !mch_isdir(p_bsdir))
-	    errmsg = e_invarg;
-    }
-#endif
-
-    /* 'keymodel' */
-    else if (varp == &p_km)
-    {
-	if (check_opt_strings(p_km, p_km_values, TRUE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    km_stopsel = (vim_strchr(p_km, 'o') != NULL);
-	    km_startsel = (vim_strchr(p_km, 'a') != NULL);
-	}
-    }
-
-    /* 'mousemodel' */
-    else if (varp == &p_mousem)
-    {
-	if (check_opt_strings(p_mousem, p_mousem_values, FALSE) != OK)
-	    errmsg = e_invarg;
-#if defined(FEAT_GUI_MOTIF) && defined(FEAT_MENU) && (XmVersion <= 1002)
-	else if (*p_mousem != *oldval)
-	    /* Changed from "extend" to "popup" or "popup_setpos" or vv: need
-	     * to create or delete the popup menus. */
-	    gui_motif_update_mousemodel(root_menu);
-#endif
-    }
-
-    /* 'switchbuf' */
-    else if (varp == &p_swb)
-    {
-	if (opt_strings_flags(p_swb, p_swb_values, &swb_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'debug' */
-    else if (varp == &p_debug)
-    {
-	if (check_opt_strings(p_debug, p_debug_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'display' */
-    else if (varp == &p_dy)
-    {
-	if (opt_strings_flags(p_dy, p_dy_values, &dy_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-	else
-	    (void)init_chartab();
-
-    }
-
-    /* 'eadirection' */
-    else if (varp == &p_ead)
-    {
-	if (check_opt_strings(p_ead, p_ead_values, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_CLIPBOARD
-    /* 'clipboard' */
-    else if (varp == &p_cb)
-	errmsg = check_clipboard_option();
-#endif
-
-#ifdef FEAT_SPELL
-    /* When 'spelllang' or 'spellfile' is set and there is a window for this
-     * buffer in which 'spell' is set load the wordlists. */
-    else if (varp == &(curwin->w_s->b_p_spl)
-	    || varp == &(curwin->w_s->b_p_spf))
-    {
-	int	is_spellfile = varp == &(curwin->w_s->b_p_spf);
-
-	if ((is_spellfile && !valid_spellfile(*varp))
-	    || (!is_spellfile && !valid_spellang(*varp)))
-	    errmsg = e_invarg;
-	else
-	    errmsg = did_set_spell_option(is_spellfile);
-    }
-    /* When 'spellcapcheck' is set compile the regexp program. */
-    else if (varp == &(curwin->w_s->b_p_spc))
-    {
-	errmsg = compile_cap_prog(curwin->w_s);
-    }
-    /* 'spellsuggest' */
-    else if (varp == &p_sps)
-    {
-	if (spell_check_sps() != OK)
-	    errmsg = e_invarg;
-    }
-    /* 'mkspellmem' */
-    else if (varp == &p_msm)
-    {
-	if (spell_check_msm() != OK)
-	    errmsg = e_invarg;
-    }
-#endif
-
-    /* When 'bufhidden' is set, check for valid value. */
-    else if (gvarp == &p_bh)
-    {
-	if (check_opt_strings(curbuf->b_p_bh, p_bufhidden_values, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* When 'buftype' is set, check for valid value. */
-    else if (gvarp == &p_bt)
-    {
-	if (check_opt_strings(curbuf->b_p_bt, p_buftype_values, FALSE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    if (curwin->w_status_height)
-	    {
-		curwin->w_redr_status = TRUE;
-		redraw_later(VALID);
-	    }
-	    curbuf->b_help = (curbuf->b_p_bt[0] == 'h');
-#ifdef FEAT_TITLE
-	    redraw_titles();
-#endif
-	}
-    }
-
-#ifdef FEAT_STL_OPT
-    /* 'statusline' or 'rulerformat' */
-    else if (gvarp == &p_stl || varp == &p_ruf)
-    {
-	int wid;
-
-	if (varp == &p_ruf)	/* reset ru_wid first */
-	    ru_wid = 0;
-	s = *varp;
-	if (varp == &p_ruf && *s == '%')
-	{
-	    /* set ru_wid if 'ruf' starts with "%99(" */
-	    if (*++s == '-')	/* ignore a '-' */
-		s++;
-	    wid = getdigits(&s);
-	    if (wid && *s == '(' && (errmsg = check_stl_option(p_ruf)) == NULL)
-		ru_wid = wid;
-	    else
-		errmsg = check_stl_option(p_ruf);
-	}
-	/* check 'statusline' only if it doesn't start with "%!" */
-	else if (varp == &p_ruf || s[0] != '%' || s[1] != '!')
-	    errmsg = check_stl_option(s);
-	if (varp == &p_ruf && errmsg == NULL)
-	    comp_col();
-    }
-#endif
-
-    /* check if it is a valid value for 'complete' -- Acevedo */
-    else if (gvarp == &p_cpt)
-    {
-	for (s = *varp; *s;)
-	{
-	    while (*s == ',' || *s == ' ')
-		s++;
-	    if (!*s)
-		break;
-	    if (vim_strchr((char_u *)".wbuksid]tU", *s) == NULL)
-	    {
-		errmsg = illegal_char(errbuf, *s);
-		break;
-	    }
-	    if (*++s != NUL && *s != ',' && *s != ' ')
-	    {
-		if (s[-1] == 'k' || s[-1] == 's')
-		{
-		    /* skip optional filename after 'k' and 's' */
-		    while (*s && *s != ',' && *s != ' ')
-		    {
-			if (*s == '\\' && s[1] != NUL)
-			    ++s;
-			++s;
-		    }
-		}
-		else
-		{
-		    if (errbuf != NULL)
-		    {
-			sprintf((char *)errbuf,
-				     _("E535: Illegal character after <%c>"),
-				     *--s);
-			errmsg = errbuf;
-		    }
-		    else
-			errmsg = "";
-		    break;
-		}
-	    }
-	}
-    }
-
-    // 'completeopt'
-    else if (varp == &p_cot)
-    {
-	if (check_opt_strings(p_cot, p_cot_values, TRUE) != OK)
-	    errmsg = e_invarg;
-	else
-	    completeopt_was_set();
-    }
-
-#ifdef BACKSLASH_IN_FILENAME
-    // 'completeslash'
-    else if (gvarp == &p_csl)
-    {
-	if (check_opt_strings(p_csl, p_csl_values, FALSE) != OK
-		|| check_opt_strings(curbuf->b_p_csl, p_csl_values, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-#endif
-
-#ifdef FEAT_SIGNS
-    // 'signcolumn'
-    else if (varp == &curwin->w_p_scl)
-    {
-	if (check_opt_strings(*varp, p_scl_values, FALSE) != OK)
-	    errmsg = e_invarg;
-	// When changing the 'signcolumn' to or from 'number', recompute the
-	// width of the number column if 'number' or 'relativenumber' is set.
-	if (((*oldval == 'n' && *(oldval + 1) == 'u')
-		|| (*curwin->w_p_scl == 'n' && *(curwin->w_p_scl + 1) =='u'))
-		&& (curwin->w_p_nu || curwin->w_p_rnu))
-	    curwin->w_nrwidth_line_count = 0;
-    }
-#endif
-
-
-#if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
-    /* 'toolbar' */
-    else if (varp == &p_toolbar)
-    {
-	if (opt_strings_flags(p_toolbar, p_toolbar_values,
-			      &toolbar_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    out_flush();
-	    gui_mch_show_toolbar((toolbar_flags &
-				  (TOOLBAR_TEXT | TOOLBAR_ICONS)) != 0);
-	}
-    }
-#endif
-
-#if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
-    /* 'toolbariconsize': GTK+ 2 only */
-    else if (varp == &p_tbis)
-    {
-	if (opt_strings_flags(p_tbis, p_tbis_values, &tbis_flags, FALSE) != OK)
-	    errmsg = e_invarg;
-	else
-	{
-	    out_flush();
-	    gui_mch_show_toolbar((toolbar_flags &
-				  (TOOLBAR_TEXT | TOOLBAR_ICONS)) != 0);
-	}
-    }
-#endif
-
-    /* 'pastetoggle': translate key codes like in a mapping */
-    else if (varp == &p_pt)
-    {
-	if (*p_pt)
-	{
-	    (void)replace_termcodes(p_pt, &p, TRUE, TRUE, FALSE);
-	    if (p != NULL)
-	    {
-		if (new_value_alloced)
-		    free_string_option(p_pt);
-		p_pt = p;
-		new_value_alloced = TRUE;
-	    }
-	}
-    }
-
-    /* 'backspace' */
-    else if (varp == &p_bs)
-    {
-	if (VIM_ISDIGIT(*p_bs))
-	{
-	    if (*p_bs > '2' || p_bs[1] != NUL)
-		errmsg = e_invarg;
-	}
-	else if (check_opt_strings(p_bs, p_bs_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-    else if (varp == &p_bo)
-    {
-	if (opt_strings_flags(p_bo, p_bo_values, &bo_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'tagcase' */
-    else if (gvarp == &p_tc)
-    {
-	unsigned int	*flags;
-
-	if (opt_flags & OPT_LOCAL)
-	{
-	    p = curbuf->b_p_tc;
-	    flags = &curbuf->b_tc_flags;
-	}
-	else
-	{
-	    p = p_tc;
-	    flags = &tc_flags;
-	}
-
-	if ((opt_flags & OPT_LOCAL) && *p == NUL)
-	    /* make the local value empty: use the global value */
-	    *flags = 0;
-	else if (*p == NUL
-		|| opt_strings_flags(p, p_tc_values, flags, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-
-    /* 'casemap' */
-    else if (varp == &p_cmp)
-    {
-	if (opt_strings_flags(p_cmp, p_cmp_values, &cmp_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-
-#ifdef FEAT_DIFF
-    /* 'diffopt' */
-    else if (varp == &p_dip)
-    {
-	if (diffopt_changed() == FAIL)
-	    errmsg = e_invarg;
-    }
-#endif
-
-#ifdef FEAT_FOLDING
-    /* 'foldmethod' */
-    else if (gvarp == &curwin->w_allbuf_opt.wo_fdm)
-    {
-	if (check_opt_strings(*varp, p_fdm_values, FALSE) != OK
-		|| *curwin->w_p_fdm == NUL)
-	    errmsg = e_invarg;
-	else
-	{
-	    foldUpdateAll(curwin);
-	    if (foldmethodIsDiff(curwin))
-		newFoldLevel();
-	}
-    }
-# ifdef FEAT_EVAL
-    /* 'foldexpr' */
-    else if (varp == &curwin->w_p_fde)
-    {
-	if (foldmethodIsExpr(curwin))
-	    foldUpdateAll(curwin);
-    }
-# endif
-    /* 'foldmarker' */
-    else if (gvarp == &curwin->w_allbuf_opt.wo_fmr)
-    {
-	p = vim_strchr(*varp, ',');
-	if (p == NULL)
-	    errmsg = N_("E536: comma required");
-	else if (p == *varp || p[1] == NUL)
-	    errmsg = e_invarg;
-	else if (foldmethodIsMarker(curwin))
-	    foldUpdateAll(curwin);
-    }
-    /* 'commentstring' */
-    else if (gvarp == &p_cms)
-    {
-	if (**varp != NUL && strstr((char *)*varp, "%s") == NULL)
-	    errmsg = N_("E537: 'commentstring' must be empty or contain %s");
-    }
-    /* 'foldopen' */
-    else if (varp == &p_fdo)
-    {
-	if (opt_strings_flags(p_fdo, p_fdo_values, &fdo_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-    /* 'foldclose' */
-    else if (varp == &p_fcl)
-    {
-	if (check_opt_strings(p_fcl, p_fcl_values, TRUE) != OK)
-	    errmsg = e_invarg;
-    }
-    /* 'foldignore' */
-    else if (gvarp == &curwin->w_allbuf_opt.wo_fdi)
-    {
-	if (foldmethodIsIndent(curwin))
-	    foldUpdateAll(curwin);
-    }
-#endif
-
-    /* 'virtualedit' */
-    else if (varp == &p_ve)
-    {
-	if (opt_strings_flags(p_ve, p_ve_values, &ve_flags, TRUE) != OK)
-	    errmsg = e_invarg;
-	else if (STRCMP(p_ve, oldval) != 0)
-	{
-	    /* Recompute cursor position in case the new 've' setting
-	     * changes something. */
-	    validate_virtcol();
-	    coladvance(curwin->w_virtcol);
-	}
-    }
-
-#if defined(FEAT_CSCOPE) && defined(FEAT_QUICKFIX)
-    else if (varp == &p_csqf)
-    {
-	if (p_csqf != NULL)
-	{
-	    p = p_csqf;
-	    while (*p != NUL)
-	    {
-		if (vim_strchr((char_u *)CSQF_CMDS, *p) == NULL
-			|| p[1] == NUL
-			|| vim_strchr((char_u *)CSQF_FLAGS, p[1]) == NULL
-			|| (p[2] != NUL && p[2] != ','))
-		{
-		    errmsg = e_invarg;
-		    break;
-		}
-		else if (p[2] == NUL)
-		    break;
-		else
-		    p += 3;
-	    }
-	}
-    }
-#endif
-
-#ifdef FEAT_CINDENT
-    /* 'cinoptions' */
-    else if (gvarp == &p_cino)
-    {
-	/* TODO: recognize errors */
-	parse_cino(curbuf);
-    }
-#endif
-
-#if defined(FEAT_RENDER_OPTIONS)
-    /* 'renderoptions' */
-    else if (varp == &p_rop)
-    {
-	if (!gui_mch_set_rendering_options(p_rop))
-	    errmsg = e_invarg;
-    }
-#endif
-
-    else if (gvarp == &p_ft)
-    {
-	if (!valid_filetype(*varp))
-	    errmsg = e_invarg;
-	else
-	{
-	    value_changed = STRCMP(oldval, *varp) != 0;
-
-	    // Since we check the value, there is no need to set P_INSECURE,
-	    // even when the value comes from a modeline.
-	    *value_checked = TRUE;
-	}
-    }
-
-#ifdef FEAT_SYN_HL
-    else if (gvarp == &p_syn)
-    {
-	if (!valid_filetype(*varp))
-	    errmsg = e_invarg;
-	else
-	{
-	    value_changed = STRCMP(oldval, *varp) != 0;
-
-	    // Since we check the value, there is no need to set P_INSECURE,
-	    // even when the value comes from a modeline.
-	    *value_checked = TRUE;
-	}
-    }
-#endif
-
-#ifdef FEAT_TERMINAL
-    // 'termwinkey'
-    else if (varp == &curwin->w_p_twk)
-    {
-	if (*curwin->w_p_twk != NUL
-				  && string_to_key(curwin->w_p_twk, TRUE) == 0)
-	    errmsg = e_invarg;
-    }
-    // 'termwinsize'
-    else if (varp == &curwin->w_p_tws)
-    {
-	if (*curwin->w_p_tws != NUL)
-	{
-	    p = skipdigits(curwin->w_p_tws);
-	    if (p == curwin->w_p_tws
-		    || (*p != 'x' && *p != '*')
-		    || *skipdigits(p + 1) != NUL)
-		errmsg = e_invarg;
-	}
-    }
-# if defined(MSWIN)
-    // 'termwintype'
-    else if (varp == &p_twt)
-    {
-	if (check_opt_strings(*varp, p_twt_values, FALSE) != OK)
-	    errmsg = e_invarg;
-    }
-# endif
-#endif
-
-#ifdef FEAT_VARTABS
-    /* 'varsofttabstop' */
-    else if (varp == &(curbuf->b_p_vsts))
-    {
-	char_u *cp;
-
-	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
-	{
-	    if (curbuf->b_p_vsts_array)
-	    {
-		vim_free(curbuf->b_p_vsts_array);
-		curbuf->b_p_vsts_array = 0;
-	    }
-	}
-	else
-	{
-	    for (cp = *varp; *cp; ++cp)
-	    {
-		if (vim_isdigit(*cp))
-		    continue;
-		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
-		    continue;
-		errmsg = e_invarg;
-		break;
-	    }
-	    if (errmsg == NULL)
-	    {
-		int *oldarray = curbuf->b_p_vsts_array;
-		if (tabstop_set(*varp, &(curbuf->b_p_vsts_array)))
-		{
-		    if (oldarray)
-			vim_free(oldarray);
-		}
-		else
-		    errmsg = e_invarg;
-	    }
-	}
-    }
-
-    /* 'vartabstop' */
-    else if (varp == &(curbuf->b_p_vts))
-    {
-	char_u *cp;
-
-	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
-	{
-	    if (curbuf->b_p_vts_array)
-	    {
-		vim_free(curbuf->b_p_vts_array);
-		curbuf->b_p_vts_array = NULL;
-	    }
-	}
-	else
-	{
-	    for (cp = *varp; *cp; ++cp)
-	    {
-		if (vim_isdigit(*cp))
-		    continue;
-		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
-		    continue;
-		errmsg = e_invarg;
-		break;
-	    }
-	    if (errmsg == NULL)
-	    {
-		int *oldarray = curbuf->b_p_vts_array;
-
-		if (tabstop_set(*varp, &(curbuf->b_p_vts_array)))
-		{
-		    vim_free(oldarray);
-#ifdef FEAT_FOLDING
-		    if (foldmethodIsIndent(curwin))
-			foldUpdateAll(curwin);
-#endif
-		}
-		else
-		    errmsg = e_invarg;
-	    }
-	}
-    }
-#endif
-
-#ifdef FEAT_TEXT_PROP
-    // 'previewpopup'
-    else if (varp == &p_pvp)
-    {
-	if (parse_previewpopup(NULL) == FAIL)
-	    errmsg = e_invarg;
-    }
-# ifdef FEAT_QUICKFIX
-    // 'completepopup'
-    else if (varp == &p_cpp)
-    {
-	if (parse_completepopup(NULL) == FAIL)
-	    errmsg = e_invarg;
-    }
-# endif
-#endif
-
-    /* Options that are a list of flags. */
-    else
-    {
-	p = NULL;
-	if (varp == &p_ww) /* 'whichwrap' */
-	    p = (char_u *)WW_ALL;
-	if (varp == &p_shm) /* 'shortmess' */
-	    p = (char_u *)SHM_ALL;
-	else if (varp == &(p_cpo)) /* 'cpoptions' */
-	    p = (char_u *)CPO_ALL;
-	else if (varp == &(curbuf->b_p_fo)) /* 'formatoptions' */
-	    p = (char_u *)FO_ALL;
-#ifdef FEAT_CONCEAL
-	else if (varp == &curwin->w_p_cocu) /* 'concealcursor' */
-	    p = (char_u *)COCU_ALL;
-#endif
-	else if (varp == &p_mouse) /* 'mouse' */
-	{
-#ifdef FEAT_MOUSE
-	    p = (char_u *)MOUSE_ALL;
-#else
-	    if (*p_mouse != NUL)
-		errmsg = N_("E538: No mouse support");
-#endif
-	}
-#if defined(FEAT_GUI)
-	else if (varp == &p_go) /* 'guioptions' */
-	    p = (char_u *)GO_ALL;
-#endif
-	if (p != NULL)
-	{
-	    for (s = *varp; *s; ++s)
-		if (vim_strchr(p, *s) == NULL)
-		{
-		    errmsg = illegal_char(errbuf, *s);
-		    break;
-		}
-	}
-    }
-
-    /*
-     * If error detected, restore the previous value.
-     */
-    if (errmsg != NULL)
-    {
-	if (new_value_alloced)
-	    free_string_option(*varp);
-	*varp = oldval;
-	/*
-	 * When resetting some values, need to act on it.
-	 */
-	if (did_chartab)
-	    (void)init_chartab();
-	if (varp == &p_hl)
-	    (void)highlight_changed();
-    }
-    else
-    {
-#ifdef FEAT_EVAL
-	/* Remember where the option was set. */
-	set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
-#endif
-	/*
-	 * Free string options that are in allocated memory.
-	 * Use "free_oldval", because recursiveness may change the flags under
-	 * our fingers (esp. init_highlight()).
-	 */
-	if (free_oldval)
-	    free_string_option(oldval);
-	if (new_value_alloced)
-	    options[opt_idx].flags |= P_ALLOCED;
-	else
-	    options[opt_idx].flags &= ~P_ALLOCED;
-
-	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
-		&& ((int)options[opt_idx].indir & PV_BOTH))
-	{
-	    /* global option with local value set to use global value; free
-	     * the local value and make it empty */
-	    p = get_varp_scope(&(options[opt_idx]), OPT_LOCAL);
-	    free_string_option(*(char_u **)p);
-	    *(char_u **)p = empty_option;
-	}
-
-	/* May set global value for local option. */
-	else if (!(opt_flags & OPT_LOCAL) && opt_flags != OPT_GLOBAL)
-	    set_string_option_global(opt_idx, varp);
-
-	/*
-	 * Trigger the autocommand only after setting the flags.
-	 */
-#ifdef FEAT_SYN_HL
-	/* When 'syntax' is set, load the syntax of that name */
-	if (varp == &(curbuf->b_p_syn))
-	{
-	    static int syn_recursive = 0;
-
-	    ++syn_recursive;
-	    // Only pass TRUE for "force" when the value changed or not used
-	    // recursively, to avoid endless recurrence.
-	    apply_autocmds(EVENT_SYNTAX, curbuf->b_p_syn, curbuf->b_fname,
-		    value_changed || syn_recursive == 1, curbuf);
-	    curbuf->b_flags |= BF_SYN_SET;
-	    --syn_recursive;
-	}
-#endif
-	else if (varp == &(curbuf->b_p_ft))
-	{
-	    /* 'filetype' is set, trigger the FileType autocommand.
-	     * Skip this when called from a modeline and the filetype was
-	     * already set to this value. */
-	    if (!(opt_flags & OPT_MODELINE) || value_changed)
-	    {
-		static int  ft_recursive = 0;
-		int	    secure_save = secure;
-
-		// Reset the secure flag, since the value of 'filetype' has
-		// been checked to be safe.
-		secure = 0;
-
-		++ft_recursive;
-		did_filetype = TRUE;
-		// Only pass TRUE for "force" when the value changed or not
-		// used recursively, to avoid endless recurrence.
-		apply_autocmds(EVENT_FILETYPE, curbuf->b_p_ft, curbuf->b_fname,
-				   value_changed || ft_recursive == 1, curbuf);
-		--ft_recursive;
-		/* Just in case the old "curbuf" is now invalid. */
-		if (varp != &(curbuf->b_p_ft))
-		    varp = NULL;
-
-		secure = secure_save;
-	    }
-	}
-#ifdef FEAT_SPELL
-	if (varp == &(curwin->w_s->b_p_spl))
-	{
-	    char_u	fname[200];
-	    char_u	*q = curwin->w_s->b_p_spl;
-
-	    /* Skip the first name if it is "cjk". */
-	    if (STRNCMP(q, "cjk,", 4) == 0)
-		q += 4;
-
-	    /*
-	     * Source the spell/LANG.vim in 'runtimepath'.
-	     * They could set 'spellcapcheck' depending on the language.
-	     * Use the first name in 'spelllang' up to '_region' or
-	     * '.encoding'.
-	     */
-	    for (p = q; *p != NUL; ++p)
-		if (!ASCII_ISALNUM(*p) && *p != '-')
-		    break;
-	    if (p > q)
-	    {
-		vim_snprintf((char *)fname, 200, "spell/%.*s.vim",
-							      (int)(p - q), q);
-		source_runtime(fname, DIP_ALL);
-	    }
-	}
-#endif
-    }
-
-#ifdef FEAT_MOUSE
-    if (varp == &p_mouse)
-    {
-# ifdef FEAT_MOUSE_TTY
-	if (*p_mouse == NUL)
-	    mch_setmouse(FALSE);    /* switch mouse off */
-	else
-# endif
-	    setmouse();		    /* in case 'mouse' changed */
-    }
-#endif
-
-    if (curwin->w_curswant != MAXCOL
-		     && (options[opt_idx].flags & (P_CURSWANT | P_RALL)) != 0)
-	curwin->w_set_curswant = TRUE;
-
-#ifdef FEAT_GUI
-    /* check redraw when it's not a GUI option or the GUI is active. */
-    if (!redraw_gui_only || gui.in_use)
-#endif
-	check_redraw(options[opt_idx].flags);
-
-#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-    if (did_swaptcap)
-    {
-	set_termname((char_u *)"win32");
-	init_highlight(TRUE, FALSE);
-    }
-#endif
-
-    return errmsg;
-}
-
-#ifdef FEAT_STL_OPT
-/*
- * Check validity of options with the 'statusline' format.
- * Return error message or NULL.
- */
-    static char *
-check_stl_option(char_u *s)
-{
-    int		itemcnt = 0;
-    int		groupdepth = 0;
-    static char errbuf[80];
-
-    while (*s && itemcnt < STL_MAX_ITEM)
-    {
-	/* Check for valid keys after % sequences */
-	while (*s && *s != '%')
-	    s++;
-	if (!*s)
-	    break;
-	s++;
-	if (*s != '%' && *s != ')')
-	    ++itemcnt;
-	if (*s == '%' || *s == STL_TRUNCMARK || *s == STL_MIDDLEMARK)
-	{
-	    s++;
-	    continue;
-	}
-	if (*s == ')')
-	{
-	    s++;
-	    if (--groupdepth < 0)
-		break;
-	    continue;
-	}
-	if (*s == '-')
-	    s++;
-	while (VIM_ISDIGIT(*s))
-	    s++;
-	if (*s == STL_USER_HL)
-	    continue;
-	if (*s == '.')
-	{
-	    s++;
-	    while (*s && VIM_ISDIGIT(*s))
-		s++;
-	}
-	if (*s == '(')
-	{
-	    groupdepth++;
-	    continue;
-	}
-	if (vim_strchr(STL_ALL, *s) == NULL)
-	{
-	    return illegal_char(errbuf, *s);
-	}
-	if (*s == '{')
-	{
-	    s++;
-	    while (*s != '}' && *s)
-		s++;
-	    if (*s != '}')
-		return N_("E540: Unclosed expression sequence");
-	}
-    }
-    if (itemcnt >= STL_MAX_ITEM)
-	return N_("E541: too many items");
-    if (groupdepth != 0)
-	return N_("E542: unbalanced groups");
-    return NULL;
-}
-#endif
-
-#ifdef FEAT_CLIPBOARD
+#if defined(FEAT_CLIPBOARD) || defined(PROTO)
 /*
  * Extract the items in the 'clipboard' option and set global values.
  * Return an error message or NULL for success.
  */
-    static char *
+    char *
 check_clipboard_option(void)
 {
     int		new_unnamed = 0;
@@ -4955,7 +2589,7 @@
  * Set the script_ctx for an option, taking care of setting the buffer- or
  * window-local value.
  */
-    static void
+    void
 set_option_sctx_idx(int opt_idx, int opt_flags, sctx_T script_ctx)
 {
     int		both = (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0;
@@ -6222,7 +3856,7 @@
 /*
  * Called after an option changed: check if something needs to be redrawn.
  */
-    static void
+    void
 check_redraw(long_u flags)
 {
     /* Careful: P_RCLR and P_RALL are a combination of other P_ flags */
@@ -6248,7 +3882,7 @@
  * Find index for option 'arg'.
  * Return -1 if not found.
  */
-    static int
+    int
 findoption(char_u *arg)
 {
     int		    opt_idx;
@@ -6608,6 +4242,81 @@
 #endif
 
 /*
+ * Return the flags for the option at 'opt_idx'.
+ */
+    long_u
+get_option_flags(int opt_idx)
+{
+    return options[opt_idx].flags;
+}
+
+/*
+ * Set a flag for the option at 'opt_idx'.
+ */
+    void
+set_option_flag(int opt_idx, long_u flag)
+{
+    options[opt_idx].flags |= flag;
+}
+
+/*
+ * Clear a flag for the option at 'opt_idx'.
+ */
+    void
+clear_option_flag(int opt_idx, long_u flag)
+{
+    options[opt_idx].flags &= ~flag;
+}
+
+/*
+ * Returns TRUE if the option at 'opt_idx' is a global option
+ */
+    int
+is_global_option(int opt_idx)
+{
+    return options[opt_idx].indir == PV_NONE;
+}
+
+/*
+ * Returns TRUE if the option at 'opt_idx' is a global option which also has a
+ * local value.
+ */
+    int
+is_global_local_option(int opt_idx)
+{
+    return options[opt_idx].indir & PV_BOTH;
+}
+
+/*
+ * Returns TRUE if the option at 'opt_idx' is a window-local option
+ */
+    int
+is_window_local_option(int opt_idx)
+{
+    return options[opt_idx].var == VAR_WIN;
+}
+
+/*
+ * Returns TRUE if the option at 'opt_idx' is a hidden option
+ */
+    int
+is_hidden_option(int opt_idx)
+{
+    return options[opt_idx].var == NULL;
+}
+
+#if defined(FEAT_CRYPT) || defined(PROTO)
+/*
+ * Returns TRUE if the option at 'opt_idx' is a crypt key option
+ */
+    int
+is_crypt_key_option(int opt_idx)
+{
+    return options[opt_idx].indir == PV_KEY;
+}
+#endif
+
+/*
  * Set the value of option "name".
  * Use "string" for string options, use "number" for other options.
  *
@@ -7348,6 +5057,15 @@
     return (p->fullname[0] == 't' && p->fullname[1] == '_');
 }
 
+/*
+ * Returns TRUE if the option at 'opt_idx' starts with 't_'
+ */
+    int
+istermoption_idx(int opt_idx)
+{
+    return istermoption(&options[opt_idx]);
+}
+
 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
 /*
  * Unset local option value, similar to ":set opt<".
@@ -7512,6 +5230,16 @@
 }
 
 /*
+ * Get pointer to option variable at 'opt_idx', depending on local or global
+ * scope.
+ */
+    char_u *
+get_option_varp_scope(int opt_idx, int opt_flags)
+{
+    return get_varp_scope(&(options[opt_idx]), opt_flags);
+}
+
+/*
  * Get pointer to option variable.
  */
     static char_u *
@@ -7763,6 +5491,24 @@
 }
 
 /*
+ * Return a pointer to the variable for option at 'opt_idx'
+ */
+    char_u *
+get_option_var(int opt_idx)
+{
+    return options[opt_idx].var;
+}
+
+/*
+ * Return the full name of the option at 'opt_idx'
+ */
+    char_u *
+get_option_fullname(int opt_idx)
+{
+    return (char_u *)options[opt_idx].fullname;
+}
+
+/*
  * Get the value of 'equalprg', either the buffer-local one or the global one.
  */
     char_u *
@@ -8540,7 +6286,7 @@
 	    if (xp->xp_context == EXPAND_BOOL_SETTINGS
 	      && !(options[opt_idx].flags & P_BOOL))
 		continue;
-	    is_term_opt = istermoption(&options[opt_idx]);
+	    is_term_opt = istermoption_idx(opt_idx);
 	    if (is_term_opt && num_normal > 0)
 		continue;
 	    match = FALSE;
@@ -8983,7 +6729,7 @@
     if (!option_was_set((char_u *)"cp"))
     {
 	p_cp = FALSE;
-	for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
+	for (opt_idx = 0; !istermoption_idx(opt_idx); opt_idx++)
 	    if (!(options[opt_idx].flags & (P_WAS_SET|P_VI_DEF)))
 		set_option_default(opt_idx, OPT_FREE, FALSE);
 	didset_options();
@@ -9072,7 +6818,7 @@
 {
     int	    opt_idx;
 
-    for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
+    for (opt_idx = 0; !istermoption_idx(opt_idx); opt_idx++)
 	if (	   ((options[opt_idx].flags & P_VIM) && p_cp)
 		|| (!(options[opt_idx].flags & P_VI_DEF) && !p_cp))
 	    set_option_default(opt_idx, OPT_FREE, p_cp);
@@ -9080,12 +6826,12 @@
     didset_options2();
 }
 
-#ifdef FEAT_LINEBREAK
+#if defined(FEAT_LINEBREAK) || defined(PROTO)
 
 /*
  * fill_breakat_flags() -- called when 'breakat' changes value.
  */
-    static void
+    void
 fill_breakat_flags(void)
 {
     char_u	*p;
@@ -9101,65 +6847,9 @@
 #endif
 
 /*
- * Check an option that can be a range of string values.
- *
- * Return OK for correct value, FAIL otherwise.
- * Empty is always OK.
- */
-    static int
-check_opt_strings(
-    char_u	*val,
-    char	**values,
-    int		list)	    /* when TRUE: accept a list of values */
-{
-    return opt_strings_flags(val, values, NULL, list);
-}
-
-/*
- * Handle an option that can be a range of string values.
- * Set a flag in "*flagp" for each string present.
- *
- * Return OK for correct value, FAIL otherwise.
- * Empty is always OK.
- */
-    static int
-opt_strings_flags(
-    char_u	*val,		/* new value */
-    char	**values,	/* array of valid string values */
-    unsigned	*flagp,
-    int		list)		/* when TRUE: accept a list of values */
-{
-    int		i;
-    int		len;
-    unsigned	new_flags = 0;
-
-    while (*val)
-    {
-	for (i = 0; ; ++i)
-	{
-	    if (values[i] == NULL)	/* val not found in values[] */
-		return FAIL;
-
-	    len = (int)STRLEN(values[i]);
-	    if (STRNCMP(values[i], val, len) == 0
-		    && ((list && val[len] == ',') || val[len] == NUL))
-	    {
-		val += len + (val[len] == ',');
-		new_flags |= (1 << i);
-		break;		/* check next item in val list */
-	    }
-	}
-    }
-    if (flagp != NULL)
-	*flagp = new_flags;
-
-    return OK;
-}
-
-/*
  * Read the 'wildmode' option, fill wim_flags[].
  */
-    static int
+    int
 check_opt_wim(void)
 {
     char_u	new_wim_flags[4];
@@ -9280,15 +6970,6 @@
 }
 
 /*
- * return OK if "p" is a valid fileformat name, FAIL otherwise.
- */
-    int
-check_ff_value(char_u *p)
-{
-    return check_opt_strings(p, p_ff_values, FALSE);
-}
-
-/*
  * Return the effective 'scrolloff' value for the current window, using the
  * global value when appropriate.
  */
@@ -9409,7 +7090,7 @@
  * This is called when 'breakindentopt' is changed and when a window is
  * initialized.
  */
-    static int
+    int
 briopt_check(win_T *wp)
 {
     char_u	*p;
@@ -9498,7 +7179,7 @@
     if (d == NULL)
 	return NULL;
 
-    for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
+    for (opt_idx = 0; !istermoption_idx(opt_idx); opt_idx++)
     {
 	struct vimoption *opt = &options[opt_idx];
 
@@ -9523,11 +7204,11 @@
 }
 #endif
 
-#ifdef FEAT_SYN_HL
+#if defined(FEAT_SYN_HL) || defined(PROTO)
 /*
  * This is called when 'culopt' is changed
  */
-    static int
+    int
 fill_culopt_flags(char_u *val, win_T *wp)
 {
     char_u	*p;
diff --git a/src/option.h b/src/option.h
index 1d85843..35efcab 100644
--- a/src/option.h
+++ b/src/option.h
@@ -10,6 +10,53 @@
  * option.h: definition of global variables for settable options
  */
 
+//
+// Flags
+//
+#define P_BOOL		0x01	// the option is boolean
+#define P_NUM		0x02	// the option is numeric
+#define P_STRING	0x04	// the option is a string
+#define P_ALLOCED	0x08	// the string option is in allocated memory,
+				// must use free_string_option() when
+				// assigning new value. Not set if default is
+				// the same.
+#define P_EXPAND	0x10	// environment expansion.  NOTE: P_EXPAND can
+				// never be used for local or hidden options!
+#define P_NODEFAULT	0x40	// don't set to default value
+#define P_DEF_ALLOCED	0x80	// default value is in allocated memory, must
+				//  use vim_free() when assigning new value
+#define P_WAS_SET	0x100	// option has been set/reset
+#define P_NO_MKRC	0x200	// don't include in :mkvimrc output
+#define P_VI_DEF	0x400	// Use Vi default for Vim
+#define P_VIM		0x800	// Vim option, reset when 'cp' set
+
+				// when option changed, what to display:
+#define P_RSTAT		0x1000	// redraw status lines
+#define P_RWIN		0x2000	// redraw current window and recompute text
+#define P_RBUF		0x4000	// redraw current buffer and recompute text
+#define P_RALL		0x6000	// redraw all windows
+#define P_RCLR		0x7000	// clear and redraw all
+
+#define P_COMMA		 0x8000	 // comma separated list
+#define P_ONECOMMA	0x18000L // P_COMMA and cannot have two consecutive
+				 // commas
+#define P_NODUP		0x20000L // don't allow duplicate strings
+#define P_FLAGLIST	0x40000L // list of single-char flags
+
+#define P_SECURE	0x80000L // cannot change in modeline or secure mode
+#define P_GETTEXT      0x100000L // expand default value with _()
+#define P_NOGLOB       0x200000L // do not use local value for global vimrc
+#define P_NFNAME       0x400000L // only normal file name chars allowed
+#define P_INSECURE     0x800000L // option was set from a modeline
+#define P_PRI_MKRC    0x1000000L // priority for :mkvimrc (setting option has
+				 // side effects)
+#define P_NO_ML       0x2000000L // not allowed in modeline
+#define P_CURSWANT    0x4000000L // update curswant required; not needed when
+				 // there is a redraw flag
+#define P_NDNAME      0x8000000L // only normal dir name chars allowed
+#define P_RWINONLY   0x10000000L // only redraw current window
+#define P_MLE	     0x20000000L // under control of 'modelineexpr'
+
 /*
  * Default values for 'errorformat'.
  * The "%f|%l| %m" one is used for when the contents of the quickfix window is
@@ -311,11 +358,26 @@
 #ifdef FEAT_RIGHTLEFT
 EXTERN long	p_aleph;	// 'aleph'
 #endif
+EXTERN char_u	*p_ambw;	// 'ambiwidth'
 #ifdef FEAT_AUTOCHDIR
 EXTERN int	p_acd;		// 'autochdir'
 #endif
-EXTERN char_u	*p_ambw;	// 'ambiwidth'
-EXTERN char_u	*p_emoji;	// 'emoji'
+EXTERN int	p_ai;		// 'autoindent'
+EXTERN int	p_bin;		// 'binary'
+EXTERN int	p_bomb;		// 'bomb'
+EXTERN int	p_bl;		// 'buflisted'
+#ifdef FEAT_CINDENT
+EXTERN int	p_cin;		// 'cindent'
+EXTERN char_u	*p_cink;	// 'cinkeys'
+#endif
+#if defined(FEAT_SMARTINDENT) || defined(FEAT_CINDENT)
+EXTERN char_u	*p_cinw;	// 'cinwords'
+#endif
+#ifdef FEAT_COMPL_FUNC
+EXTERN char_u	*p_cfu;		// 'completefunc'
+EXTERN char_u	*p_ofu;		// 'omnifunc'
+#endif
+EXTERN int	p_ci;		// 'copyindent'
 #if defined(FEAT_GUI) && defined(MACOS_X)
 EXTERN int	*p_antialias;	// 'antialias'
 #endif
@@ -327,9 +389,6 @@
 EXTERN int	p_bk;		// 'backup'
 EXTERN char_u	*p_bkc;		// 'backupcopy'
 EXTERN unsigned	bkc_flags;	// flags from 'backupcopy'
-#ifdef IN_OPTION_C
-static char *(p_bkc_values[]) = {"yes", "auto", "no", "breaksymlink", "breakhardlink", NULL};
-#endif
 # define BKC_YES		0x001
 # define BKC_AUTO		0x002
 # define BKC_NO			0x004
@@ -339,13 +398,6 @@
 EXTERN char_u	*p_bex;		// 'backupext'
 EXTERN char_u	*p_bo;		// 'belloff'
 EXTERN unsigned	bo_flags;
-# ifdef IN_OPTION_C
-static char *(p_bo_values[]) = {"all", "backspace", "cursor", "complete",
-				 "copy", "ctrlg", "error", "esc", "ex",
-				 "hangul", "insertmode", "lang", "mess",
-				 "showmatch", "operator", "register", "shell",
-				 "spell", "wildmode", NULL};
-# endif
 
 // values for the 'beepon' option
 #define BO_ALL		0x0001
@@ -392,11 +444,10 @@
 #ifdef FEAT_LINEBREAK
 EXTERN char_u	*p_breakat;	// 'breakat'
 #endif
+EXTERN char_u	*p_bh;		// 'bufhidden'
+EXTERN char_u	*p_bt;		// 'buftype'
 EXTERN char_u	*p_cmp;		// 'casemap'
 EXTERN unsigned	cmp_flags;
-#ifdef IN_OPTION_C
-static char *(p_cmp_values[]) = {"internal", "keepascii", NULL};
-#endif
 #define CMP_INTERNAL		0x001
 #define CMP_KEEPASCII		0x002
 EXTERN char_u	*p_enc;		// 'encoding'
@@ -404,6 +455,7 @@
 #ifdef FEAT_EVAL
 EXTERN char_u	*p_ccv;		// 'charconvert'
 #endif
+EXTERN char_u	*p_cino;	// 'cinoptions'
 #ifdef FEAT_CMDWIN
 EXTERN char_u	*p_cedit;	// 'cedit'
 EXTERN long	p_cwh;		// 'cmdwinheight'
@@ -412,6 +464,10 @@
 EXTERN char_u	*p_cb;		// 'clipboard'
 #endif
 EXTERN long	p_ch;		// 'cmdheight'
+#ifdef FEAT_FOLDING
+EXTERN char_u	*p_cms;		// 'commentstring'
+#endif
+EXTERN char_u	*p_cpt;		// 'complete'
 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
 EXTERN int	p_confirm;	// 'confirm'
 #endif
@@ -422,6 +478,9 @@
 #endif
 EXTERN long	p_ph;		// 'pumheight'
 EXTERN long	p_pw;		// 'pumwidth'
+#ifdef FEAT_COMMENTS
+EXTERN char_u	*p_com;		// 'comments'
+#endif
 EXTERN char_u	*p_cpo;		// 'cpoptions'
 #ifdef FEAT_CSCOPE
 EXTERN char_u	*p_csprg;	// 'cscopeprg'
@@ -454,14 +513,12 @@
 EXTERN char_u	*p_dir;		// 'directory'
 EXTERN char_u	*p_dy;		// 'display'
 EXTERN unsigned	dy_flags;
-#ifdef IN_OPTION_C
-static char *(p_dy_values[]) = {"lastline", "truncate", "uhex", NULL};
-#endif
 #define DY_LASTLINE		0x001
 #define DY_TRUNCATE		0x002
 #define DY_UHEX			0x004
 EXTERN int	p_ed;		// 'edcompatible'
 EXTERN char_u	*p_ead;		// 'eadirection'
+EXTERN char_u	*p_emoji;	// 'emoji'
 EXTERN int	p_ea;		// 'equalalways'
 EXTERN char_u	*p_ep;		// 'equalprg'
 EXTERN int	p_eb;		// 'errorbells'
@@ -471,22 +528,24 @@
 EXTERN char_u	*p_gefm;	// 'grepformat'
 EXTERN char_u	*p_gp;		// 'grepprg'
 #endif
-EXTERN char_u	*p_ei;		// 'eventignore'
+EXTERN int	p_eol;		// 'endofline'
 EXTERN int	p_ek;		// 'esckeys'
+EXTERN char_u	*p_ei;		// 'eventignore'
+EXTERN int	p_et;		// 'expandtab'
 EXTERN int	p_exrc;		// 'exrc'
+EXTERN char_u	*p_fenc;	// 'fileencoding'
 EXTERN char_u	*p_fencs;	// 'fileencodings'
+EXTERN char_u	*p_ff;		// 'fileformat'
 EXTERN char_u	*p_ffs;		// 'fileformats'
 EXTERN long	p_fic;		// 'fileignorecase'
+EXTERN char_u	*p_ft;		// 'filetype'
+EXTERN char_u	*p_fcs;		// 'fillchar'
+EXTERN int	p_fixeol;	// 'fixendofline'
 #ifdef FEAT_FOLDING
 EXTERN char_u	*p_fcl;		// 'foldclose'
 EXTERN long	p_fdls;		// 'foldlevelstart'
 EXTERN char_u	*p_fdo;		// 'foldopen'
 EXTERN unsigned	fdo_flags;
-# ifdef IN_OPTION_C
-static char *(p_fdo_values[]) = {"all", "block", "hor", "mark", "percent",
-				 "quickfix", "search", "tag", "insert",
-				 "undo", "jump", NULL};
-# endif
 # define FDO_ALL		0x001
 # define FDO_BLOCK		0x002
 # define FDO_HOR		0x004
@@ -499,6 +558,11 @@
 # define FDO_UNDO		0x200
 # define FDO_JUMP		0x400
 #endif
+#if defined(FEAT_EVAL)
+EXTERN char_u	*p_fex;		// 'formatexpr'
+#endif
+EXTERN char_u	*p_flp;		// 'formatlistpat'
+EXTERN char_u	*p_fo;		// 'formatoptions'
 EXTERN char_u	*p_fp;		// 'formatprg'
 #ifdef HAVE_FSYNC
 EXTERN int	p_fs;		// 'fsync'
@@ -580,12 +644,29 @@
 #endif
 EXTERN int	p_imcmdline;	// 'imcmdline'
 EXTERN int	p_imdisable;	// 'imdisable'
+EXTERN long	p_iminsert;	// 'iminsert'
+EXTERN long	p_imsearch;	// 'imsearch'
+EXTERN int	p_inf;		// 'infercase'
+#if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
+EXTERN char_u	*p_inex;	// 'includeexpr'
+#endif
 EXTERN int	p_is;		// 'incsearch'
+#if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
+EXTERN char_u	*p_inde;	// 'indentexpr'
+EXTERN char_u	*p_indk;	// 'indentkeys'
+#endif
 EXTERN int	p_im;		// 'insertmode'
 EXTERN char_u	*p_isf;		// 'isfname'
 EXTERN char_u	*p_isi;		// 'isident'
+EXTERN char_u	*p_isk;		// 'iskeyword'
 EXTERN char_u	*p_isp;		// 'isprint'
 EXTERN int	p_js;		// 'joinspaces'
+#ifdef FEAT_CRYPT
+EXTERN char_u	*p_key;		// 'key'
+#endif
+#ifdef FEAT_KEYMAP
+EXTERN char_u	*p_keymap;	// 'keymap'
+#endif
 EXTERN char_u	*p_kp;		// 'keywordprg'
 EXTERN char_u	*p_km;		// 'keymodel'
 #ifdef FEAT_LANGMAP
@@ -600,6 +681,7 @@
 EXTERN long	p_linespace;	// 'linespace'
 #endif
 #ifdef FEAT_LISP
+EXTERN int	p_lisp;		// 'lisp'
 EXTERN char_u	*p_lispwords;	// 'lispwords'
 #endif
 EXTERN long	p_ls;		// 'laststatus'
@@ -620,6 +702,7 @@
 EXTERN char_u	*p_mef;		// 'makeef'
 EXTERN char_u	*p_mp;		// 'makeprg'
 #endif
+EXTERN char_u	*p_mps;		// 'matchpairs'
 #ifdef FEAT_SIGNS
 EXTERN char_u  *p_scl;		// signcolumn
 #endif
@@ -642,8 +725,11 @@
 #ifdef FEAT_SPELL
 EXTERN char_u	*p_msm;		// 'mkspellmem'
 #endif
+EXTERN int	p_ml;		// 'modeline'
 EXTERN long	p_mle;		// 'modelineexpr'
 EXTERN long	p_mls;		// 'modelines'
+EXTERN int	p_ma;		// 'modifiable'
+EXTERN int	p_mod;		// 'modified'
 EXTERN char_u	*p_mouse;	// 'mouse'
 #ifdef FEAT_GUI
 EXTERN int	p_mousef;	// 'mousefocus'
@@ -659,6 +745,7 @@
 EXTERN char_u	*p_mzschemegcdll; // 'mzschemegcdll'
 # endif
 #endif
+EXTERN char_u	*p_nf;		// 'nrformats'
 #if defined(MSWIN)
 EXTERN int	p_odev;		// 'opendevice'
 #endif
@@ -677,6 +764,7 @@
 #if defined(DYNAMIC_PERL)
 EXTERN char_u	*p_perldll;	// 'perldll'
 #endif
+EXTERN int	p_pi;		// 'preserveindent'
 #if defined(DYNAMIC_PYTHON3)
 EXTERN char_u	*p_py3dll;	// 'pythonthreedll'
 #endif
@@ -692,6 +780,10 @@
 #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3)
 EXTERN long	p_pyx;		// 'pyxversion'
 #endif
+#ifdef FEAT_TEXTOBJ
+EXTERN char_u	*p_qe;		// 'quoteescape'
+#endif
+EXTERN int	p_ro;		// 'readonly'
 #ifdef FEAT_RELTIME
 EXTERN long	p_rdt;		// 'redrawtime'
 #endif
@@ -732,12 +824,6 @@
 #ifdef FEAT_SESSION
 EXTERN char_u	*p_ssop;	// 'sessionoptions'
 EXTERN unsigned	ssop_flags;
-# ifdef IN_OPTION_C
-// Also used for 'viewoptions'!
-static char *(p_ssop_values[]) = {"buffers", "winpos", "resize", "winsize",
-    "localoptions", "options", "help", "blank", "globals", "slash", "unix",
-    "sesdir", "curdir", "folds", "cursor", "tabpages", "terminal", NULL};
-# endif
 # define SSOP_BUFFERS		0x001
 # define SSOP_WINPOS		0x002
 # define SSOP_RESIZE		0x004
@@ -776,7 +862,9 @@
 EXTERN char_u	*p_stl;		// 'statusline'
 #endif
 EXTERN int	p_sr;		// 'shiftround'
+EXTERN long	p_sw;		// 'shiftwidth'
 EXTERN char_u	*p_shm;		// 'shortmess'
+EXTERN int	p_sn;		// 'shortname'
 #ifdef FEAT_LINEBREAK
 EXTERN char_u	*p_sbr;		// 'showbreak'
 #endif
@@ -789,13 +877,30 @@
 EXTERN long	p_ss;		// 'sidescroll'
 EXTERN long	p_siso;		// 'sidescrolloff'
 EXTERN int	p_scs;		// 'smartcase'
+#ifdef FEAT_SMARTINDENT
+EXTERN int	p_si;		// 'smartindent'
+#endif
 EXTERN int	p_sta;		// 'smarttab'
+EXTERN long	p_sts;		// 'softtabstop'
 EXTERN int	p_sb;		// 'splitbelow'
+#if defined(FEAT_SEARCHPATH)
+EXTERN char_u	*p_sua;		// 'suffixesadd'
+#endif
+EXTERN int	p_swf;		// 'swapfile'
+#ifdef FEAT_SYN_HL
+EXTERN long	p_smc;		// 'synmaxcol'
+#endif
 EXTERN long	p_tpm;		// 'tabpagemax'
-# if defined(FEAT_STL_OPT)
+#ifdef FEAT_STL_OPT
 EXTERN char_u	*p_tal;		// 'tabline'
-# endif
+#endif
+#ifdef FEAT_EVAL
+EXTERN char_u	*p_tfu;		// 'tagfunc'
+#endif
 #ifdef FEAT_SPELL
+EXTERN char_u	*p_spc;		// 'spellcapcheck'
+EXTERN char_u	*p_spf;		// 'spellfile'
+EXTERN char_u	*p_spl;		// 'spelllang'
 EXTERN char_u	*p_sps;		// 'spellsuggest'
 #endif
 EXTERN int	p_spr;		// 'splitright'
@@ -804,20 +909,16 @@
 EXTERN char_u	*p_sws;		// 'swapsync'
 EXTERN char_u	*p_swb;		// 'switchbuf'
 EXTERN unsigned	swb_flags;
-#ifdef IN_OPTION_C
-static char *(p_swb_values[]) = {"useopen", "usetab", "split", "newtab", "vsplit", NULL};
-#endif
 #define SWB_USEOPEN		0x001
 #define SWB_USETAB		0x002
 #define SWB_SPLIT		0x004
 #define SWB_NEWTAB		0x008
 #define SWB_VSPLIT		0x010
+EXTERN char_u	*p_syn;		// 'syntax'
+EXTERN long	p_ts;		// 'tabstop'
 EXTERN int	p_tbs;		// 'tagbsearch'
 EXTERN char_u	*p_tc;		// 'tagcase'
 EXTERN unsigned tc_flags;       // flags from 'tagcase'
-#ifdef IN_OPTION_C
-static char *(p_tc_values[]) = {"followic", "ignore", "match", "followscs", "smart", NULL};
-#endif
 #define TC_FOLLOWIC		0x01
 #define TC_IGNORE		0x02
 #define TC_MATCH		0x04
@@ -837,11 +938,16 @@
 #ifdef FEAT_TERMGUICOLORS
 EXTERN int	p_tgc;		// 'termguicolors'
 #endif
+#ifdef FEAT_TERMINAL
+EXTERN long	p_twsl;		// 'termwinscroll'
+#endif
 #if defined(MSWIN) && defined(FEAT_TERMINAL)
 EXTERN char_u	*p_twt;		// 'termwintype'
 #endif
 EXTERN int	p_terse;	// 'terse'
 EXTERN int	p_ta;		// 'textauto'
+EXTERN int	p_tx;		// 'textmode'
+EXTERN long	p_tw;		// 'textwidth'
 EXTERN int	p_to;		// 'tildeop'
 EXTERN int	p_timeout;	// 'timeout'
 EXTERN long	p_tm;		// 'timeoutlen'
@@ -859,9 +965,6 @@
 #if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
 EXTERN char_u	*p_toolbar;	// 'toolbar'
 EXTERN unsigned toolbar_flags;
-# ifdef IN_OPTION_C
-static char *(p_toolbar_values[]) = {"text", "icons", "tooltips", "horiz", NULL};
-# endif
 # define TOOLBAR_TEXT		0x01
 # define TOOLBAR_ICONS		0x02
 # define TOOLBAR_TOOLTIPS	0x04
@@ -870,9 +973,6 @@
 #if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
 EXTERN char_u	*p_tbis;	// 'toolbariconsize'
 EXTERN unsigned tbis_flags;
-# ifdef IN_OPTION_C
-static char *(p_tbis_values[]) = {"tiny", "small", "medium", "large", "huge", "giant", NULL};
-# endif
 # define TBIS_TINY		0x01
 # define TBIS_SMALL		0x02
 # define TBIS_MEDIUM		0x04
@@ -884,9 +984,6 @@
 #if defined(FEAT_MOUSE) && (defined(UNIX) || defined(VMS))
 EXTERN char_u	*p_ttym;	// 'ttymouse'
 EXTERN unsigned ttym_flags;
-# ifdef IN_OPTION_C
-static char *(p_ttym_values[]) = {"xterm", "xterm2", "dec", "netterm", "jsbterm", "pterm", "urxvt", "sgr", NULL};
-# endif
 # define TTYM_XTERM		0x01
 # define TTYM_XTERM2		0x02
 # define TTYM_DEC		0x04
@@ -897,11 +994,17 @@
 # define TTYM_SGR		0x80
 #endif
 EXTERN char_u	*p_udir;	// 'undodir'
+#ifdef FEAT_PERSISTENT_UNDO
+EXTERN int	p_udf;		// 'undofile'
+#endif
 EXTERN long	p_ul;		// 'undolevels'
 EXTERN long	p_ur;		// 'undoreload'
 EXTERN long	p_uc;		// 'updatecount'
 EXTERN long	p_ut;		// 'updatetime'
-EXTERN char_u	*p_fcs;		// 'fillchar'
+#ifdef FEAT_VARTABS
+EXTERN char_u	*p_vsts;	// 'varsofttabstop'
+EXTERN char_u	*p_vts;		// 'vartabstop'
+#endif
 #ifdef FEAT_VIMINFO
 EXTERN char_u	*p_viminfo;	// 'viminfo'
 EXTERN char_u	*p_viminfofile;	// 'viminfofile'
@@ -914,9 +1017,6 @@
 EXTERN int	p_vb;		// 'visualbell'
 EXTERN char_u	*p_ve;		// 'virtualedit'
 EXTERN unsigned ve_flags;
-#ifdef IN_OPTION_C
-static char *(p_ve_values[]) = {"block", "insert", "all", "onemore", NULL};
-#endif
 #define VE_BLOCK	5	// includes "all"
 #define VE_INSERT	6	// includes "all"
 #define VE_ALL		4
@@ -954,6 +1054,7 @@
 #if defined(MSWIN) && defined(FEAT_TERMINAL)
 EXTERN char_u	*p_winptydll;	// 'winptydll'
 #endif
+EXTERN long	p_wm;		// 'wrapmargin'
 EXTERN int	p_ws;		// 'wrapscan'
 EXTERN int	p_write;	// 'write'
 EXTERN int	p_wa;		// 'writeany'
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 8e9d3f9..c21c8f6 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -243,112 +243,6 @@
 // buffers.  Indicate this by setting "var" to VAR_WIN.
 #define VAR_WIN ((char_u *)-1)
 
-// These are the global values for options which are also local to a buffer.
-// Only to be used in option.c!
-static int	p_ai;
-static int	p_bin;
-static int	p_bomb;
-static char_u	*p_bh;
-static char_u	*p_bt;
-static int	p_bl;
-static int	p_ci;
-#ifdef FEAT_CINDENT
-static int	p_cin;
-static char_u	*p_cink;
-static char_u	*p_cino;
-#endif
-#if defined(FEAT_SMARTINDENT) || defined(FEAT_CINDENT)
-static char_u	*p_cinw;
-#endif
-#ifdef FEAT_COMMENTS
-static char_u	*p_com;
-#endif
-#ifdef FEAT_FOLDING
-static char_u	*p_cms;
-#endif
-static char_u	*p_cpt;
-#ifdef FEAT_COMPL_FUNC
-static char_u	*p_cfu;
-static char_u	*p_ofu;
-#endif
-#ifdef FEAT_EVAL
-static char_u	*p_tfu;
-#endif
-static int	p_eol;
-static int	p_fixeol;
-static int	p_et;
-static char_u	*p_fenc;
-static char_u	*p_ff;
-static char_u	*p_fo;
-static char_u	*p_flp;
-static char_u	*p_ft;
-static long	p_iminsert;
-static long	p_imsearch;
-#if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
-static char_u	*p_inex;
-#endif
-#if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
-static char_u	*p_inde;
-static char_u	*p_indk;
-#endif
-#if defined(FEAT_EVAL)
-static char_u	*p_fex;
-#endif
-static int	p_inf;
-static char_u	*p_isk;
-#ifdef FEAT_CRYPT
-static char_u	*p_key;
-#endif
-#ifdef FEAT_LISP
-static int	p_lisp;
-#endif
-static int	p_ml;
-static int	p_ma;
-static int	p_mod;
-static char_u	*p_mps;
-static char_u	*p_nf;
-static int	p_pi;
-#ifdef FEAT_TEXTOBJ
-static char_u	*p_qe;
-#endif
-static int	p_ro;
-#ifdef FEAT_SMARTINDENT
-static int	p_si;
-#endif
-static int	p_sn;
-static long	p_sts;
-#if defined(FEAT_SEARCHPATH)
-static char_u	*p_sua;
-#endif
-static long	p_sw;
-static int	p_swf;
-#ifdef FEAT_SYN_HL
-static long	p_smc;
-static char_u	*p_syn;
-#endif
-#ifdef FEAT_SPELL
-static char_u	*p_spc;
-static char_u	*p_spf;
-static char_u	*p_spl;
-#endif
-static long	p_ts;
-static long	p_tw;
-static int	p_tx;
-#ifdef FEAT_PERSISTENT_UNDO
-static int	p_udf;
-#endif
-static long	p_wm;
-#ifdef FEAT_VARTABS
-static char_u	*p_vsts;
-static char_u	*p_vts;
-#endif
-#ifdef FEAT_KEYMAP
-static char_u	*p_keymap;
-#endif
-#ifdef FEAT_TERMINAL
-static long	p_twsl;		// 'termwinscroll'
-#endif
-
 // Saved values for when 'bin' is set.
 static int	p_et_nobin;
 static int	p_ml_nobin;
@@ -387,53 +281,6 @@
 #define VI_DEFAULT  0	    // def_val[VI_DEFAULT] is Vi default value
 #define VIM_DEFAULT 1	    // def_val[VIM_DEFAULT] is Vim default value
 
-//
-// Flags
-//
-#define P_BOOL		0x01	// the option is boolean
-#define P_NUM		0x02	// the option is numeric
-#define P_STRING	0x04	// the option is a string
-#define P_ALLOCED	0x08	// the string option is in allocated memory,
-				// must use free_string_option() when
-				// assigning new value. Not set if default is
-				// the same.
-#define P_EXPAND	0x10	// environment expansion.  NOTE: P_EXPAND can
-				// never be used for local or hidden options!
-#define P_NODEFAULT	0x40	// don't set to default value
-#define P_DEF_ALLOCED	0x80	// default value is in allocated memory, must
-				//  use vim_free() when assigning new value
-#define P_WAS_SET	0x100	// option has been set/reset
-#define P_NO_MKRC	0x200	// don't include in :mkvimrc output
-#define P_VI_DEF	0x400	// Use Vi default for Vim
-#define P_VIM		0x800	// Vim option, reset when 'cp' set
-
-				// when option changed, what to display:
-#define P_RSTAT		0x1000	// redraw status lines
-#define P_RWIN		0x2000	// redraw current window and recompute text
-#define P_RBUF		0x4000	// redraw current buffer and recompute text
-#define P_RALL		0x6000	// redraw all windows
-#define P_RCLR		0x7000	// clear and redraw all
-
-#define P_COMMA		 0x8000	 // comma separated list
-#define P_ONECOMMA	0x18000L // P_COMMA and cannot have two consecutive
-				 // commas
-#define P_NODUP		0x20000L // don't allow duplicate strings
-#define P_FLAGLIST	0x40000L // list of single-char flags
-
-#define P_SECURE	0x80000L // cannot change in modeline or secure mode
-#define P_GETTEXT      0x100000L // expand default value with _()
-#define P_NOGLOB       0x200000L // do not use local value for global vimrc
-#define P_NFNAME       0x400000L // only normal file name chars allowed
-#define P_INSECURE     0x800000L // option was set from a modeline
-#define P_PRI_MKRC    0x1000000L // priority for :mkvimrc (setting option has
-				 // side effects)
-#define P_NO_ML       0x2000000L // not allowed in modeline
-#define P_CURSWANT    0x4000000L // update curswant required; not needed when
-				 // there is a redraw flag
-#define P_NDNAME      0x8000000L // only normal dir name chars allowed
-#define P_RWINONLY   0x10000000L // only redraw current window
-#define P_MLE	     0x20000000L // under control of 'modelineexpr'
-
 #define ISK_LATIN1  (char_u *)"@,48-57,_,192-255"
 
 // 'isprint' for latin1 is also used for MS-Windows cp1252, where 0x80 is used
@@ -3158,45 +3005,5 @@
 
 #define PARAM_COUNT (sizeof(options) / sizeof(struct vimoption))
 
-static char *(p_ambw_values[]) = {"single", "double", NULL};
-static char *(p_bg_values[]) = {"light", "dark", NULL};
-static char *(p_nf_values[]) = {"bin", "octal", "hex", "alpha", NULL};
-static char *(p_ff_values[]) = {FF_UNIX, FF_DOS, FF_MAC, NULL};
-#ifdef FEAT_CRYPT
-static char *(p_cm_values[]) = {"zip", "blowfish", "blowfish2", NULL};
-#endif
-static char *(p_wop_values[]) = {"tagfile", NULL};
-#ifdef FEAT_WAK
-static char *(p_wak_values[]) = {"yes", "menu", "no", NULL};
-#endif
-static char *(p_mousem_values[]) = {"extend", "popup", "popup_setpos", "mac", NULL};
-static char *(p_sel_values[]) = {"inclusive", "exclusive", "old", NULL};
-static char *(p_slm_values[]) = {"mouse", "key", "cmd", NULL};
-static char *(p_km_values[]) = {"startsel", "stopsel", NULL};
-#ifdef FEAT_BROWSE
-static char *(p_bsdir_values[]) = {"current", "last", "buffer", NULL};
-#endif
-static char *(p_scbopt_values[]) = {"ver", "hor", "jump", NULL};
-static char *(p_debug_values[]) = {"msg", "throw", "beep", NULL};
-static char *(p_ead_values[]) = {"both", "ver", "hor", NULL};
-static char *(p_buftype_values[]) = {"nofile", "nowrite", "quickfix", "help", "terminal", "acwrite", "prompt", "popup", NULL};
-static char *(p_bufhidden_values[]) = {"hide", "unload", "delete", "wipe", NULL};
-static char *(p_bs_values[]) = {"indent", "eol", "start", NULL};
-#ifdef FEAT_FOLDING
-static char *(p_fdm_values[]) = {"manual", "expr", "marker", "indent", "syntax",
-# ifdef FEAT_DIFF
-				"diff",
-# endif
-				NULL};
-static char *(p_fcl_values[]) = {"all", NULL};
-#endif
-static char *(p_cot_values[]) = {"menu", "menuone", "longest", "preview", "popup", "noinsert", "noselect", NULL};
-#ifdef BACKSLASH_IN_FILENAME
-static char *(p_csl_values[]) = {"slash", "backslash", NULL};
-#endif
-#ifdef FEAT_SIGNS
-static char *(p_scl_values[]) = {"yes", "no", "auto", "number", NULL};
-#endif
-#if defined(MSWIN) && defined(FEAT_TERMINAL)
-static char *(p_twt_values[]) = {"winpty", "conpty", "", NULL};
-#endif
+// The following is needed to make the gen_opt_test.vim script work.
+// {"
diff --git a/src/optionstr.c b/src/optionstr.c
new file mode 100644
index 0000000..44f0759
--- /dev/null
+++ b/src/optionstr.c
@@ -0,0 +1,2491 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * optionstr.c: Functions related to string options
+ */
+
+#include "vim.h"
+
+static char *(p_ambw_values[]) = {"single", "double", NULL};
+static char *(p_bg_values[]) = {"light", "dark", NULL};
+static char *(p_bkc_values[]) = {"yes", "auto", "no", "breaksymlink", "breakhardlink", NULL};
+static char *(p_bo_values[]) = {"all", "backspace", "cursor", "complete",
+				 "copy", "ctrlg", "error", "esc", "ex",
+				 "hangul", "insertmode", "lang", "mess",
+				 "showmatch", "operator", "register", "shell",
+				 "spell", "wildmode", NULL};
+static char *(p_nf_values[]) = {"bin", "octal", "hex", "alpha", NULL};
+static char *(p_ff_values[]) = {FF_UNIX, FF_DOS, FF_MAC, NULL};
+#ifdef FEAT_CRYPT
+static char *(p_cm_values[]) = {"zip", "blowfish", "blowfish2", NULL};
+#endif
+static char *(p_cmp_values[]) = {"internal", "keepascii", NULL};
+static char *(p_dy_values[]) = {"lastline", "truncate", "uhex", NULL};
+#ifdef FEAT_FOLDING
+static char *(p_fdo_values[]) = {"all", "block", "hor", "mark", "percent",
+				 "quickfix", "search", "tag", "insert",
+				 "undo", "jump", NULL};
+#endif
+#ifdef FEAT_SESSION
+// Also used for 'viewoptions'!
+static char *(p_ssop_values[]) = {"buffers", "winpos", "resize", "winsize",
+    "localoptions", "options", "help", "blank", "globals", "slash", "unix",
+    "sesdir", "curdir", "folds", "cursor", "tabpages", "terminal", NULL};
+#endif
+static char *(p_swb_values[]) = {"useopen", "usetab", "split", "newtab", "vsplit", NULL};
+static char *(p_tc_values[]) = {"followic", "ignore", "match", "followscs", "smart", NULL};
+#if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
+static char *(p_toolbar_values[]) = {"text", "icons", "tooltips", "horiz", NULL};
+#endif
+#if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
+static char *(p_tbis_values[]) = {"tiny", "small", "medium", "large", "huge", "giant", NULL};
+#endif
+#if defined(FEAT_MOUSE) && (defined(UNIX) || defined(VMS))
+static char *(p_ttym_values[]) = {"xterm", "xterm2", "dec", "netterm", "jsbterm", "pterm", "urxvt", "sgr", NULL};
+#endif
+static char *(p_ve_values[]) = {"block", "insert", "all", "onemore", NULL};
+static char *(p_wop_values[]) = {"tagfile", NULL};
+#ifdef FEAT_WAK
+static char *(p_wak_values[]) = {"yes", "menu", "no", NULL};
+#endif
+static char *(p_mousem_values[]) = {"extend", "popup", "popup_setpos", "mac", NULL};
+static char *(p_sel_values[]) = {"inclusive", "exclusive", "old", NULL};
+static char *(p_slm_values[]) = {"mouse", "key", "cmd", NULL};
+static char *(p_km_values[]) = {"startsel", "stopsel", NULL};
+#ifdef FEAT_BROWSE
+static char *(p_bsdir_values[]) = {"current", "last", "buffer", NULL};
+#endif
+static char *(p_scbopt_values[]) = {"ver", "hor", "jump", NULL};
+static char *(p_debug_values[]) = {"msg", "throw", "beep", NULL};
+static char *(p_ead_values[]) = {"both", "ver", "hor", NULL};
+static char *(p_buftype_values[]) = {"nofile", "nowrite", "quickfix", "help", "terminal", "acwrite", "prompt", "popup", NULL};
+static char *(p_bufhidden_values[]) = {"hide", "unload", "delete", "wipe", NULL};
+static char *(p_bs_values[]) = {"indent", "eol", "start", NULL};
+#ifdef FEAT_FOLDING
+static char *(p_fdm_values[]) = {"manual", "expr", "marker", "indent", "syntax",
+# ifdef FEAT_DIFF
+				"diff",
+# endif
+				NULL};
+static char *(p_fcl_values[]) = {"all", NULL};
+#endif
+static char *(p_cot_values[]) = {"menu", "menuone", "longest", "preview", "popup", "noinsert", "noselect", NULL};
+#ifdef BACKSLASH_IN_FILENAME
+static char *(p_csl_values[]) = {"slash", "backslash", NULL};
+#endif
+#ifdef FEAT_SIGNS
+static char *(p_scl_values[]) = {"yes", "no", "auto", "number", NULL};
+#endif
+#if defined(MSWIN) && defined(FEAT_TERMINAL)
+static char *(p_twt_values[]) = {"winpty", "conpty", "", NULL};
+#endif
+
+static int check_opt_strings(char_u *val, char **values, int list);
+static int opt_strings_flags(char_u *val, char **values, unsigned *flagp, int list);
+
+/*
+ * After setting various option values: recompute variables that depend on
+ * option values.
+ */
+    void
+didset_string_options(void)
+{
+    (void)opt_strings_flags(p_cmp, p_cmp_values, &cmp_flags, TRUE);
+    (void)opt_strings_flags(p_bkc, p_bkc_values, &bkc_flags, TRUE);
+    (void)opt_strings_flags(p_bo, p_bo_values, &bo_flags, TRUE);
+#ifdef FEAT_SESSION
+    (void)opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, TRUE);
+    (void)opt_strings_flags(p_vop, p_ssop_values, &vop_flags, TRUE);
+#endif
+#ifdef FEAT_FOLDING
+    (void)opt_strings_flags(p_fdo, p_fdo_values, &fdo_flags, TRUE);
+#endif
+    (void)opt_strings_flags(p_dy, p_dy_values, &dy_flags, TRUE);
+    (void)opt_strings_flags(p_tc, p_tc_values, &tc_flags, FALSE);
+    (void)opt_strings_flags(p_ve, p_ve_values, &ve_flags, TRUE);
+#if defined(FEAT_MOUSE) && (defined(UNIX) || defined(VMS))
+    (void)opt_strings_flags(p_ttym, p_ttym_values, &ttym_flags, FALSE);
+#endif
+#if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
+    (void)opt_strings_flags(p_toolbar, p_toolbar_values, &toolbar_flags, TRUE);
+#endif
+#if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
+    (void)opt_strings_flags(p_tbis, p_tbis_values, &tbis_flags, FALSE);
+#endif
+}
+
+#if defined(FEAT_EVAL)
+/*
+ * Trigger the OptionSet autocommand.
+ * "opt_idx"	is the index of the option being set.
+ * "opt_flags"	can be OPT_LOCAL etc.
+ * "oldval"	the old value
+ *  "oldval_l"  the old local value (only non-NULL if global and local value
+ *		are set)
+ * "oldval_g"   the old global value (only non-NULL if global and local value
+ *		are set)
+ * "newval"	the new value
+ */
+    void
+trigger_optionsset_string(
+	int	opt_idx,
+	int	opt_flags,
+	char_u  *oldval,
+	char_u  *oldval_l,
+	char_u  *oldval_g,
+	char_u  *newval)
+{
+    // Don't do this recursively.
+    if (oldval != NULL && newval != NULL
+				    && *get_vim_var_str(VV_OPTION_TYPE) == NUL)
+    {
+	char_u buf_type[7];
+
+	sprintf((char *)buf_type, "%s",
+	    (opt_flags & OPT_LOCAL) ? "local" : "global");
+	set_vim_var_string(VV_OPTION_OLD, oldval, -1);
+	set_vim_var_string(VV_OPTION_NEW, newval, -1);
+	set_vim_var_string(VV_OPTION_TYPE, buf_type, -1);
+	if (opt_flags & OPT_LOCAL)
+	{
+	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"setlocal", -1);
+	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval, -1);
+	}
+	if (opt_flags & OPT_GLOBAL)
+	{
+	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"setglobal", -1);
+	    set_vim_var_string(VV_OPTION_OLDGLOBAL, oldval, -1);
+	}
+	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
+	{
+	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"set", -1);
+	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval_l, -1);
+	    set_vim_var_string(VV_OPTION_OLDGLOBAL, oldval_g, -1);
+	}
+	if (opt_flags & OPT_MODELINE)
+	{
+	    set_vim_var_string(VV_OPTION_COMMAND, (char_u *)"modeline", -1);
+	    set_vim_var_string(VV_OPTION_OLDLOCAL, oldval, -1);
+	}
+	apply_autocmds(EVENT_OPTIONSET,
+		       (char_u *)get_option_fullname(opt_idx), NULL, FALSE,
+		       NULL);
+	reset_v_option_vars();
+    }
+}
+#endif
+
+    static char *
+illegal_char(char *errbuf, int c)
+{
+    if (errbuf == NULL)
+	return "";
+    sprintf((char *)errbuf, _("E539: Illegal character <%s>"),
+							(char *)transchar(c));
+    return errbuf;
+}
+
+/*
+ * Check string options in a buffer for NULL value.
+ */
+    void
+check_buf_options(buf_T *buf)
+{
+    check_string_option(&buf->b_p_bh);
+    check_string_option(&buf->b_p_bt);
+    check_string_option(&buf->b_p_fenc);
+    check_string_option(&buf->b_p_ff);
+#ifdef FEAT_FIND_ID
+    check_string_option(&buf->b_p_def);
+    check_string_option(&buf->b_p_inc);
+# ifdef FEAT_EVAL
+    check_string_option(&buf->b_p_inex);
+# endif
+#endif
+#if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
+    check_string_option(&buf->b_p_inde);
+    check_string_option(&buf->b_p_indk);
+#endif
+#if defined(FEAT_BEVAL) && defined(FEAT_EVAL)
+    check_string_option(&buf->b_p_bexpr);
+#endif
+#if defined(FEAT_CRYPT)
+    check_string_option(&buf->b_p_cm);
+#endif
+    check_string_option(&buf->b_p_fp);
+#if defined(FEAT_EVAL)
+    check_string_option(&buf->b_p_fex);
+#endif
+#ifdef FEAT_CRYPT
+    check_string_option(&buf->b_p_key);
+#endif
+    check_string_option(&buf->b_p_kp);
+    check_string_option(&buf->b_p_mps);
+    check_string_option(&buf->b_p_fo);
+    check_string_option(&buf->b_p_flp);
+    check_string_option(&buf->b_p_isk);
+#ifdef FEAT_COMMENTS
+    check_string_option(&buf->b_p_com);
+#endif
+#ifdef FEAT_FOLDING
+    check_string_option(&buf->b_p_cms);
+#endif
+    check_string_option(&buf->b_p_nf);
+#ifdef FEAT_TEXTOBJ
+    check_string_option(&buf->b_p_qe);
+#endif
+#ifdef FEAT_SYN_HL
+    check_string_option(&buf->b_p_syn);
+    check_string_option(&buf->b_s.b_syn_isk);
+#endif
+#ifdef FEAT_SPELL
+    check_string_option(&buf->b_s.b_p_spc);
+    check_string_option(&buf->b_s.b_p_spf);
+    check_string_option(&buf->b_s.b_p_spl);
+#endif
+#ifdef FEAT_SEARCHPATH
+    check_string_option(&buf->b_p_sua);
+#endif
+#ifdef FEAT_CINDENT
+    check_string_option(&buf->b_p_cink);
+    check_string_option(&buf->b_p_cino);
+    parse_cino(buf);
+#endif
+    check_string_option(&buf->b_p_ft);
+#if defined(FEAT_SMARTINDENT) || defined(FEAT_CINDENT)
+    check_string_option(&buf->b_p_cinw);
+#endif
+    check_string_option(&buf->b_p_cpt);
+#ifdef FEAT_COMPL_FUNC
+    check_string_option(&buf->b_p_cfu);
+    check_string_option(&buf->b_p_ofu);
+#endif
+#ifdef FEAT_EVAL
+    check_string_option(&buf->b_p_tfu);
+#endif
+#ifdef FEAT_KEYMAP
+    check_string_option(&buf->b_p_keymap);
+#endif
+#ifdef FEAT_QUICKFIX
+    check_string_option(&buf->b_p_gp);
+    check_string_option(&buf->b_p_mp);
+    check_string_option(&buf->b_p_efm);
+#endif
+    check_string_option(&buf->b_p_ep);
+    check_string_option(&buf->b_p_path);
+    check_string_option(&buf->b_p_tags);
+    check_string_option(&buf->b_p_tc);
+    check_string_option(&buf->b_p_dict);
+    check_string_option(&buf->b_p_tsr);
+#ifdef FEAT_LISP
+    check_string_option(&buf->b_p_lw);
+#endif
+    check_string_option(&buf->b_p_bkc);
+    check_string_option(&buf->b_p_menc);
+#ifdef FEAT_VARTABS
+    check_string_option(&buf->b_p_vsts);
+    check_string_option(&buf->b_p_vts);
+#endif
+}
+
+/*
+ * Free the string allocated for an option.
+ * Checks for the string being empty_option. This may happen if we're out of
+ * memory, vim_strsave() returned NULL, which was replaced by empty_option by
+ * check_options().
+ * Does NOT check for P_ALLOCED flag!
+ */
+    void
+free_string_option(char_u *p)
+{
+    if (p != empty_option)
+	vim_free(p);
+}
+
+    void
+clear_string_option(char_u **pp)
+{
+    if (*pp != empty_option)
+	vim_free(*pp);
+    *pp = empty_option;
+}
+
+    void
+check_string_option(char_u **pp)
+{
+    if (*pp == NULL)
+	*pp = empty_option;
+}
+
+/*
+ * Set global value for string option when it's a local option.
+ */
+    static void
+set_string_option_global(
+    int		opt_idx,	// option index
+    char_u	**varp)		// pointer to option variable
+{
+    char_u	**p, *s;
+
+    // the global value is always allocated
+    if (is_window_local_option(opt_idx))
+	p = (char_u **)GLOBAL_WO(varp);
+    else
+	p = (char_u **)get_option_var(opt_idx);
+    if (!is_global_option(opt_idx)
+	    && p != varp
+	    && (s = vim_strsave(*varp)) != NULL)
+    {
+	free_string_option(*p);
+	*p = s;
+    }
+}
+
+/*
+ * Set a string option to a new value (without checking the effect).
+ * The string is copied into allocated memory.
+ * if ("opt_idx" == -1) "name" is used, otherwise "opt_idx" is used.
+ * When "set_sid" is zero set the scriptID to current_sctx.sc_sid.  When
+ * "set_sid" is SID_NONE don't set the scriptID.  Otherwise set the scriptID to
+ * "set_sid".
+ */
+    void
+set_string_option_direct(
+    char_u	*name,
+    int		opt_idx,
+    char_u	*val,
+    int		opt_flags,	// OPT_FREE, OPT_LOCAL and/or OPT_GLOBAL
+    int		set_sid UNUSED)
+{
+    char_u	*s;
+    char_u	**varp;
+    int		both = (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0;
+    int		idx = opt_idx;
+
+    if (idx == -1)		// use name
+    {
+	idx = findoption(name);
+	if (idx < 0)	// not found (should not happen)
+	{
+	    semsg(_(e_intern2), "set_string_option_direct()");
+	    siemsg(_("For option %s"), name);
+	    return;
+	}
+    }
+
+    if (is_hidden_option(idx))		// can't set hidden option
+	return;
+
+    s = vim_strsave(val);
+    if (s != NULL)
+    {
+	varp = (char_u **)get_option_varp_scope(idx,
+					       both ? OPT_LOCAL : opt_flags);
+	if ((opt_flags & OPT_FREE) && (get_option_flags(idx) & P_ALLOCED))
+	    free_string_option(*varp);
+	*varp = s;
+
+	// For buffer/window local option may also set the global value.
+	if (both)
+	    set_string_option_global(idx, varp);
+
+	set_option_flag(idx, P_ALLOCED);
+
+	// When setting both values of a global option with a local value,
+	// make the local value empty, so that the global value is used.
+	if (is_global_local_option(idx) && both)
+	{
+	    free_string_option(*varp);
+	    *varp = empty_option;
+	}
+# ifdef FEAT_EVAL
+	if (set_sid != SID_NONE)
+	{
+	    sctx_T script_ctx;
+
+	    if (set_sid == 0)
+		script_ctx = current_sctx;
+	    else
+	    {
+		script_ctx.sc_sid = set_sid;
+		script_ctx.sc_seq = 0;
+		script_ctx.sc_lnum = 0;
+		script_ctx.sc_version = 1;
+	    }
+	    set_option_sctx_idx(idx, opt_flags, script_ctx);
+	}
+# endif
+    }
+}
+
+/*
+ * Like set_string_option_direct(), but for a window-local option in "wp".
+ * Blocks autocommands to avoid the old curwin becoming invalid.
+ */
+    void
+set_string_option_direct_in_win(
+	win_T		*wp,
+	char_u		*name,
+	int		opt_idx,
+	char_u		*val,
+	int		opt_flags,
+	int		set_sid)
+{
+    win_T	*save_curwin = curwin;
+
+    block_autocmds();
+    curwin = wp;
+    curbuf = curwin->w_buffer;
+    set_string_option_direct(name, opt_idx, val, opt_flags, set_sid);
+    curwin = save_curwin;
+    curbuf = curwin->w_buffer;
+    unblock_autocmds();
+}
+
+/*
+ * Like set_string_option_direct(), but for a buffer-local option in "buf".
+ * Blocks autocommands to avoid the old curbuf becoming invalid.
+ */
+    void
+set_string_option_direct_in_buf(
+	buf_T		*buf,
+	char_u		*name,
+	int		opt_idx,
+	char_u		*val,
+	int		opt_flags,
+	int		set_sid)
+{
+    buf_T	*save_curbuf = curbuf;
+
+    block_autocmds();
+    curbuf = buf;
+    curwin->w_buffer = curbuf;
+    set_string_option_direct(name, opt_idx, val, opt_flags, set_sid);
+    curbuf = save_curbuf;
+    curwin->w_buffer = curbuf;
+    unblock_autocmds();
+}
+
+/*
+ * Set a string option to a new value, and handle the effects.
+ *
+ * Returns NULL on success or error message on error.
+ */
+    char *
+set_string_option(
+    int		opt_idx,
+    char_u	*value,
+    int		opt_flags)	// OPT_LOCAL and/or OPT_GLOBAL
+{
+    char_u	*s;
+    char_u	**varp;
+    char_u	*oldval;
+#if defined(FEAT_EVAL)
+    char_u	*oldval_l = NULL;
+    char_u	*oldval_g = NULL;
+    char_u	*saved_oldval = NULL;
+    char_u	*saved_oldval_l = NULL;
+    char_u	*saved_oldval_g = NULL;
+    char_u	*saved_newval = NULL;
+#endif
+    char	*r = NULL;
+    int		value_checked = FALSE;
+
+    if (is_hidden_option(opt_idx))	// don't set hidden option
+	return NULL;
+
+    s = vim_strsave(value);
+    if (s != NULL)
+    {
+	varp = (char_u **)get_option_varp_scope(opt_idx,
+		(opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
+		    ? (is_global_local_option(opt_idx)
+			? OPT_GLOBAL : OPT_LOCAL)
+		    : opt_flags);
+	oldval = *varp;
+#if defined(FEAT_EVAL)
+	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
+	{
+	    oldval_l = *(char_u **)get_option_varp_scope(opt_idx, OPT_LOCAL);
+	    oldval_g = *(char_u **)get_option_varp_scope(opt_idx, OPT_GLOBAL);
+	}
+#endif
+	*varp = s;
+
+#if defined(FEAT_EVAL)
+	if (!starting
+# ifdef FEAT_CRYPT
+		&& !is_crypt_key_option(opt_idx)
+# endif
+		)
+	{
+	    if (oldval_l != NULL)
+		saved_oldval_l = vim_strsave(oldval_l);
+	    if (oldval_g != NULL)
+		saved_oldval_g = vim_strsave(oldval_g);
+	    saved_oldval = vim_strsave(oldval);
+	    saved_newval = vim_strsave(s);
+	}
+#endif
+	if ((r = did_set_string_option(opt_idx, varp, TRUE, oldval, NULL,
+					   opt_flags, &value_checked)) == NULL)
+	    did_set_option(opt_idx, opt_flags, TRUE, value_checked);
+
+#if defined(FEAT_EVAL)
+	// call autocommand after handling side effects
+	if (r == NULL)
+	    trigger_optionsset_string(opt_idx, opt_flags,
+				   saved_oldval, saved_oldval_l,
+				   saved_oldval_g, saved_newval);
+	vim_free(saved_oldval);
+	vim_free(saved_oldval_l);
+	vim_free(saved_oldval_g);
+	vim_free(saved_newval);
+#endif
+    }
+    return r;
+}
+
+/*
+ * Return TRUE if "val" is a valid 'filetype' name.
+ * Also used for 'syntax' and 'keymap'.
+ */
+    static int
+valid_filetype(char_u *val)
+{
+    return valid_name(val, ".-_");
+}
+
+#ifdef FEAT_STL_OPT
+/*
+ * Check validity of options with the 'statusline' format.
+ * Return error message or NULL.
+ */
+    static char *
+check_stl_option(char_u *s)
+{
+    int		itemcnt = 0;
+    int		groupdepth = 0;
+    static char errbuf[80];
+
+    while (*s && itemcnt < STL_MAX_ITEM)
+    {
+	// Check for valid keys after % sequences
+	while (*s && *s != '%')
+	    s++;
+	if (!*s)
+	    break;
+	s++;
+	if (*s != '%' && *s != ')')
+	    ++itemcnt;
+	if (*s == '%' || *s == STL_TRUNCMARK || *s == STL_MIDDLEMARK)
+	{
+	    s++;
+	    continue;
+	}
+	if (*s == ')')
+	{
+	    s++;
+	    if (--groupdepth < 0)
+		break;
+	    continue;
+	}
+	if (*s == '-')
+	    s++;
+	while (VIM_ISDIGIT(*s))
+	    s++;
+	if (*s == STL_USER_HL)
+	    continue;
+	if (*s == '.')
+	{
+	    s++;
+	    while (*s && VIM_ISDIGIT(*s))
+		s++;
+	}
+	if (*s == '(')
+	{
+	    groupdepth++;
+	    continue;
+	}
+	if (vim_strchr(STL_ALL, *s) == NULL)
+	{
+	    return illegal_char(errbuf, *s);
+	}
+	if (*s == '{')
+	{
+	    s++;
+	    while (*s != '}' && *s)
+		s++;
+	    if (*s != '}')
+		return N_("E540: Unclosed expression sequence");
+	}
+    }
+    if (itemcnt >= STL_MAX_ITEM)
+	return N_("E541: too many items");
+    if (groupdepth != 0)
+	return N_("E542: unbalanced groups");
+    return NULL;
+}
+#endif
+
+/*
+ * Handle string options that need some action to perform when changed.
+ * Returns NULL for success, or an error message for an error.
+ */
+    char *
+did_set_string_option(
+    int		opt_idx,		// index in options[] table
+    char_u	**varp,			// pointer to the option variable
+    int		new_value_alloced,	// new value was allocated
+    char_u	*oldval,		// previous value of the option
+    char	*errbuf,		// buffer for errors, or NULL
+    int		opt_flags,		// OPT_LOCAL and/or OPT_GLOBAL
+    int		*value_checked)		// value was checked to be save, no
+					// need to set P_INSECURE
+{
+    char	*errmsg = NULL;
+    char_u	*s, *p;
+    int		did_chartab = FALSE;
+    char_u	**gvarp;
+    long_u	free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
+#ifdef FEAT_GUI
+    // set when changing an option that only requires a redraw in the GUI
+    int		redraw_gui_only = FALSE;
+#endif
+    int		value_changed = FALSE;
+#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
+    int		did_swaptcap = FALSE;
+#endif
+
+    // Get the global option to compare with, otherwise we would have to check
+    // two values for all local options.
+    gvarp = (char_u **)get_option_varp_scope(opt_idx, OPT_GLOBAL);
+
+    // Disallow changing some options from secure mode
+    if ((secure
+#ifdef HAVE_SANDBOX
+		|| sandbox != 0
+#endif
+		) && (get_option_flags(opt_idx) & P_SECURE))
+	errmsg = e_secure;
+
+    // Check for a "normal" directory or file name in some options.  Disallow a
+    // path separator (slash and/or backslash), wildcards and characters that
+    // are often illegal in a file name. Be more permissive if "secure" is off.
+    else if (((get_option_flags(opt_idx) & P_NFNAME)
+		    && vim_strpbrk(*varp, (char_u *)(secure
+			    ? "/\\*?[|;&<>\r\n" : "/\\*?[<>\r\n")) != NULL)
+	  || ((get_option_flags(opt_idx) & P_NDNAME)
+		    && vim_strpbrk(*varp, (char_u *)"*?[|;&<>\r\n") != NULL))
+	errmsg = e_invarg;
+
+    // 'term'
+    else if (varp == &T_NAME)
+    {
+	if (T_NAME[0] == NUL)
+	    errmsg = N_("E529: Cannot set 'term' to empty string");
+#ifdef FEAT_GUI
+	if (gui.in_use)
+	    errmsg = N_("E530: Cannot change term in GUI");
+	else if (term_is_gui(T_NAME))
+	    errmsg = N_("E531: Use \":gui\" to start the GUI");
+#endif
+	else if (set_termname(T_NAME) == FAIL)
+	    errmsg = N_("E522: Not found in termcap");
+	else
+	{
+	    // Screen colors may have changed.
+	    redraw_later_clear();
+
+	    // Both 'term' and 'ttytype' point to T_NAME, only set the
+	    // P_ALLOCED flag on 'term'.
+	    opt_idx = findoption((char_u *)"term");
+	    free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
+	}
+    }
+
+    // 'backupcopy'
+    else if (gvarp == &p_bkc)
+    {
+	char_u		*bkc = p_bkc;
+	unsigned int	*flags = &bkc_flags;
+
+	if (opt_flags & OPT_LOCAL)
+	{
+	    bkc = curbuf->b_p_bkc;
+	    flags = &curbuf->b_bkc_flags;
+	}
+
+	if ((opt_flags & OPT_LOCAL) && *bkc == NUL)
+	    // make the local value empty: use the global value
+	    *flags = 0;
+	else
+	{
+	    if (opt_strings_flags(bkc, p_bkc_values, flags, TRUE) != OK)
+		errmsg = e_invarg;
+	    if ((((int)*flags & BKC_AUTO) != 0)
+		    + (((int)*flags & BKC_YES) != 0)
+		    + (((int)*flags & BKC_NO) != 0) != 1)
+	    {
+		// Must have exactly one of "auto", "yes"  and "no".
+		(void)opt_strings_flags(oldval, p_bkc_values, flags, TRUE);
+		errmsg = e_invarg;
+	    }
+	}
+    }
+
+    // 'backupext' and 'patchmode'
+    else if (varp == &p_bex || varp == &p_pm)
+    {
+	if (STRCMP(*p_bex == '.' ? p_bex + 1 : p_bex,
+		     *p_pm == '.' ? p_pm + 1 : p_pm) == 0)
+	    errmsg = N_("E589: 'backupext' and 'patchmode' are equal");
+    }
+#ifdef FEAT_LINEBREAK
+    // 'breakindentopt'
+    else if (varp == &curwin->w_p_briopt)
+    {
+	if (briopt_check(curwin) == FAIL)
+	    errmsg = e_invarg;
+    }
+#endif
+
+    // 'isident', 'iskeyword', 'isprint or 'isfname' option: refill g_chartab[]
+    // If the new option is invalid, use old value.  'lisp' option: refill
+    // g_chartab[] for '-' char
+    else if (  varp == &p_isi
+	    || varp == &(curbuf->b_p_isk)
+	    || varp == &p_isp
+	    || varp == &p_isf)
+    {
+	if (init_chartab() == FAIL)
+	{
+	    did_chartab = TRUE;	    // need to restore it below
+	    errmsg = e_invarg;	    // error in value
+	}
+    }
+
+    // 'helpfile'
+    else if (varp == &p_hf)
+    {
+	// May compute new values for $VIM and $VIMRUNTIME
+	if (didset_vim)
+	{
+	    vim_setenv((char_u *)"VIM", (char_u *)"");
+	    didset_vim = FALSE;
+	}
+	if (didset_vimruntime)
+	{
+	    vim_setenv((char_u *)"VIMRUNTIME", (char_u *)"");
+	    didset_vimruntime = FALSE;
+	}
+    }
+
+#ifdef FEAT_SYN_HL
+    // 'cursorlineopt'
+    else if (varp == &curwin->w_p_culopt
+				  || gvarp == &curwin->w_allbuf_opt.wo_culopt)
+    {
+	if (**varp == NUL || fill_culopt_flags(*varp, curwin) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'colorcolumn'
+    else if (varp == &curwin->w_p_cc)
+	errmsg = check_colorcolumn(curwin);
+#endif
+
+#ifdef FEAT_MULTI_LANG
+    // 'helplang'
+    else if (varp == &p_hlg)
+    {
+	// Check for "", "ab", "ab,cd", etc.
+	for (s = p_hlg; *s != NUL; s += 3)
+	{
+	    if (s[1] == NUL || ((s[2] != ',' || s[3] == NUL) && s[2] != NUL))
+	    {
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (s[2] == NUL)
+		break;
+	}
+    }
+#endif
+
+    // 'highlight'
+    else if (varp == &p_hl)
+    {
+	if (highlight_changed() == FAIL)
+	    errmsg = e_invarg;	// invalid flags
+    }
+
+    // 'nrformats'
+    else if (gvarp == &p_nf)
+    {
+	if (check_opt_strings(*varp, p_nf_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_SESSION
+    // 'sessionoptions'
+    else if (varp == &p_ssop)
+    {
+	if (opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+	if ((ssop_flags & SSOP_CURDIR) && (ssop_flags & SSOP_SESDIR))
+	{
+	    // Don't allow both "sesdir" and "curdir".
+	    (void)opt_strings_flags(oldval, p_ssop_values, &ssop_flags, TRUE);
+	    errmsg = e_invarg;
+	}
+    }
+    // 'viewoptions'
+    else if (varp == &p_vop)
+    {
+	if (opt_strings_flags(p_vop, p_ssop_values, &vop_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+#endif
+
+    // 'scrollopt'
+    else if (varp == &p_sbo)
+    {
+	if (check_opt_strings(p_sbo, p_scbopt_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'ambiwidth'
+    else if (varp == &p_ambw || varp == &p_emoji)
+    {
+	if (check_opt_strings(p_ambw, p_ambw_values, FALSE) != OK)
+	    errmsg = e_invarg;
+	else if (set_chars_option(&p_lcs) != NULL)
+	    errmsg = _("E834: Conflicts with value of 'listchars'");
+	else if (set_chars_option(&p_fcs) != NULL)
+	    errmsg = _("E835: Conflicts with value of 'fillchars'");
+    }
+
+    // 'background'
+    else if (varp == &p_bg)
+    {
+	if (check_opt_strings(p_bg, p_bg_values, FALSE) == OK)
+	{
+#ifdef FEAT_EVAL
+	    int dark = (*p_bg == 'd');
+#endif
+
+	    init_highlight(FALSE, FALSE);
+
+#ifdef FEAT_EVAL
+	    if (dark != (*p_bg == 'd')
+			  && get_var_value((char_u *)"g:colors_name") != NULL)
+	    {
+		// The color scheme must have set 'background' back to another
+		// value, that's not what we want here.  Disable the color
+		// scheme and set the colors again.
+		do_unlet((char_u *)"g:colors_name", TRUE);
+		free_string_option(p_bg);
+		p_bg = vim_strsave((char_u *)(dark ? "dark" : "light"));
+		check_string_option(&p_bg);
+		init_highlight(FALSE, FALSE);
+	    }
+#endif
+	}
+	else
+	    errmsg = e_invarg;
+    }
+
+    // 'wildmode'
+    else if (varp == &p_wim)
+    {
+	if (check_opt_wim() == FAIL)
+	    errmsg = e_invarg;
+    }
+
+    // 'wildoptions'
+    else if (varp == &p_wop)
+    {
+	if (check_opt_strings(p_wop, p_wop_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_WAK
+    // 'winaltkeys'
+    else if (varp == &p_wak)
+    {
+	if (*p_wak == NUL
+		|| check_opt_strings(p_wak, p_wak_values, FALSE) != OK)
+	    errmsg = e_invarg;
+# ifdef FEAT_MENU
+#  ifdef FEAT_GUI_MOTIF
+	else if (gui.in_use)
+	    gui_motif_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
+#  else
+#   ifdef FEAT_GUI_GTK
+	else if (gui.in_use)
+	    gui_gtk_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
+#   endif
+#  endif
+# endif
+    }
+#endif
+
+    // 'eventignore'
+    else if (varp == &p_ei)
+    {
+	if (check_ei() == FAIL)
+	    errmsg = e_invarg;
+    }
+
+    // 'encoding', 'fileencoding', 'termencoding' and 'makeencoding'
+    else if (varp == &p_enc || gvarp == &p_fenc || varp == &p_tenc
+							   || gvarp == &p_menc)
+    {
+	if (gvarp == &p_fenc)
+	{
+	    if (!curbuf->b_p_ma && opt_flags != OPT_GLOBAL)
+		errmsg = e_modifiable;
+	    else if (vim_strchr(*varp, ',') != NULL)
+		// No comma allowed in 'fileencoding'; catches confusing it
+		// with 'fileencodings'.
+		errmsg = e_invarg;
+	    else
+	    {
+#ifdef FEAT_TITLE
+		// May show a "+" in the title now.
+		redraw_titles();
+#endif
+		// Add 'fileencoding' to the swap file.
+		ml_setflags(curbuf);
+	    }
+	}
+	if (errmsg == NULL)
+	{
+	    // canonize the value, so that STRCMP() can be used on it
+	    p = enc_canonize(*varp);
+	    if (p != NULL)
+	    {
+		vim_free(*varp);
+		*varp = p;
+	    }
+	    if (varp == &p_enc)
+	    {
+		errmsg = mb_init();
+#ifdef FEAT_TITLE
+		redraw_titles();
+#endif
+	    }
+	}
+
+#if defined(FEAT_GUI_GTK)
+	if (errmsg == NULL && varp == &p_tenc && gui.in_use)
+	{
+	    // GTK+ 2 uses only a single encoding, and that is UTF-8.
+	    if (STRCMP(p_tenc, "utf-8") != 0)
+		errmsg = N_("E617: Cannot be changed in the GTK+ 2 GUI");
+	}
+#endif
+
+	if (errmsg == NULL)
+	{
+#ifdef FEAT_KEYMAP
+	    // When 'keymap' is used and 'encoding' changes, reload the keymap
+	    // (with another encoding).
+	    if (varp == &p_enc && *curbuf->b_p_keymap != NUL)
+		(void)keymap_init();
+#endif
+
+	    // When 'termencoding' is not empty and 'encoding' changes or when
+	    // 'termencoding' changes, need to setup for keyboard input and
+	    // display output conversion.
+	    if (((varp == &p_enc && *p_tenc != NUL) || varp == &p_tenc))
+	    {
+		if (convert_setup(&input_conv, p_tenc, p_enc) == FAIL
+			|| convert_setup(&output_conv, p_enc, p_tenc) == FAIL)
+		{
+		    semsg(_("E950: Cannot convert between %s and %s"),
+			    p_tenc, p_enc);
+		    errmsg = e_invarg;
+		}
+	    }
+
+#if defined(MSWIN)
+	    // $HOME may have characters in active code page.
+	    if (varp == &p_enc)
+		init_homedir();
+#endif
+	}
+    }
+
+#if defined(FEAT_POSTSCRIPT)
+    else if (varp == &p_penc)
+    {
+	// Canonize printencoding if VIM standard one
+	p = enc_canonize(p_penc);
+	if (p != NULL)
+	{
+	    vim_free(p_penc);
+	    p_penc = p;
+	}
+	else
+	{
+	    // Ensure lower case and '-' for '_'
+	    for (s = p_penc; *s != NUL; s++)
+	    {
+		if (*s == '_')
+		    *s = '-';
+		else
+		    *s = TOLOWER_ASC(*s);
+	    }
+	}
+    }
+#endif
+
+#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
+    else if (varp == &p_imak)
+    {
+	if (!im_xim_isvalid_imactivate())
+	    errmsg = e_invarg;
+    }
+#endif
+
+#ifdef FEAT_KEYMAP
+    else if (varp == &curbuf->b_p_keymap)
+    {
+	if (!valid_filetype(*varp))
+	    errmsg = e_invarg;
+	else
+	{
+	    int	    secure_save = secure;
+
+	    // Reset the secure flag, since the value of 'keymap' has
+	    // been checked to be safe.
+	    secure = 0;
+
+	    // load or unload key mapping tables
+	    errmsg = keymap_init();
+
+	    secure = secure_save;
+
+	    // Since we check the value, there is no need to set P_INSECURE,
+	    // even when the value comes from a modeline.
+	    *value_checked = TRUE;
+	}
+
+	if (errmsg == NULL)
+	{
+	    if (*curbuf->b_p_keymap != NUL)
+	    {
+		// Installed a new keymap, switch on using it.
+		curbuf->b_p_iminsert = B_IMODE_LMAP;
+		if (curbuf->b_p_imsearch != B_IMODE_USE_INSERT)
+		    curbuf->b_p_imsearch = B_IMODE_LMAP;
+	    }
+	    else
+	    {
+		// Cleared the keymap, may reset 'iminsert' and 'imsearch'.
+		if (curbuf->b_p_iminsert == B_IMODE_LMAP)
+		    curbuf->b_p_iminsert = B_IMODE_NONE;
+		if (curbuf->b_p_imsearch == B_IMODE_LMAP)
+		    curbuf->b_p_imsearch = B_IMODE_USE_INSERT;
+	    }
+	    if ((opt_flags & OPT_LOCAL) == 0)
+	    {
+		set_iminsert_global();
+		set_imsearch_global();
+	    }
+	    status_redraw_curbuf();
+	}
+    }
+#endif
+
+    // 'fileformat'
+    else if (gvarp == &p_ff)
+    {
+	if (!curbuf->b_p_ma && !(opt_flags & OPT_GLOBAL))
+	    errmsg = e_modifiable;
+	else if (check_opt_strings(*varp, p_ff_values, FALSE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    // may also change 'textmode'
+	    if (get_fileformat(curbuf) == EOL_DOS)
+		curbuf->b_p_tx = TRUE;
+	    else
+		curbuf->b_p_tx = FALSE;
+#ifdef FEAT_TITLE
+	    redraw_titles();
+#endif
+	    // update flag in swap file
+	    ml_setflags(curbuf);
+	    // Redraw needed when switching to/from "mac": a CR in the text
+	    // will be displayed differently.
+	    if (get_fileformat(curbuf) == EOL_MAC || *oldval == 'm')
+		redraw_curbuf_later(NOT_VALID);
+	}
+    }
+
+    // 'fileformats'
+    else if (varp == &p_ffs)
+    {
+	if (check_opt_strings(p_ffs, p_ff_values, TRUE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    // also change 'textauto'
+	    if (*p_ffs == NUL)
+		p_ta = FALSE;
+	    else
+		p_ta = TRUE;
+	}
+    }
+
+#if defined(FEAT_CRYPT)
+    // 'cryptkey'
+    else if (gvarp == &p_key)
+    {
+	// Make sure the ":set" command doesn't show the new value in the
+	// history.
+	remove_key_from_history();
+
+	if (STRCMP(curbuf->b_p_key, oldval) != 0)
+	    // Need to update the swapfile.
+	    ml_set_crypt_key(curbuf, oldval,
+			      *curbuf->b_p_cm == NUL ? p_cm : curbuf->b_p_cm);
+    }
+
+    else if (gvarp == &p_cm)
+    {
+	if (opt_flags & OPT_LOCAL)
+	    p = curbuf->b_p_cm;
+	else
+	    p = p_cm;
+	if (check_opt_strings(p, p_cm_values, TRUE) != OK)
+	    errmsg = e_invarg;
+	else if (crypt_self_test() == FAIL)
+	    errmsg = e_invarg;
+	else
+	{
+	    // When setting the global value to empty, make it "zip".
+	    if (*p_cm == NUL)
+	    {
+		if (new_value_alloced)
+		    free_string_option(p_cm);
+		p_cm = vim_strsave((char_u *)"zip");
+		new_value_alloced = TRUE;
+	    }
+	    // When using ":set cm=name" the local value is going to be empty.
+	    // Do that here, otherwise the crypt functions will still use the
+	    // local value.
+	    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
+	    {
+		free_string_option(curbuf->b_p_cm);
+		curbuf->b_p_cm = empty_option;
+	    }
+
+	    // Need to update the swapfile when the effective method changed.
+	    // Set "s" to the effective old value, "p" to the effective new
+	    // method and compare.
+	    if ((opt_flags & OPT_LOCAL) && *oldval == NUL)
+		s = p_cm;  // was previously using the global value
+	    else
+		s = oldval;
+	    if (*curbuf->b_p_cm == NUL)
+		p = p_cm;  // is now using the global value
+	    else
+		p = curbuf->b_p_cm;
+	    if (STRCMP(s, p) != 0)
+		ml_set_crypt_key(curbuf, curbuf->b_p_key, s);
+
+	    // If the global value changes need to update the swapfile for all
+	    // buffers using that value.
+	    if ((opt_flags & OPT_GLOBAL) && STRCMP(p_cm, oldval) != 0)
+	    {
+		buf_T	*buf;
+
+		FOR_ALL_BUFFERS(buf)
+		    if (buf != curbuf && *buf->b_p_cm == NUL)
+			ml_set_crypt_key(buf, buf->b_p_key, oldval);
+	    }
+	}
+    }
+#endif
+
+    // 'matchpairs'
+    else if (gvarp == &p_mps)
+    {
+	if (has_mbyte)
+	{
+	    for (p = *varp; *p != NUL; ++p)
+	    {
+		int x2 = -1;
+		int x3 = -1;
+
+		if (*p != NUL)
+		    p += mb_ptr2len(p);
+		if (*p != NUL)
+		    x2 = *p++;
+		if (*p != NUL)
+		{
+		    x3 = mb_ptr2char(p);
+		    p += mb_ptr2len(p);
+		}
+		if (x2 != ':' || x3 == -1 || (*p != NUL && *p != ','))
+		{
+		    errmsg = e_invarg;
+		    break;
+		}
+		if (*p == NUL)
+		    break;
+	    }
+	}
+	else
+	{
+	    // Check for "x:y,x:y"
+	    for (p = *varp; *p != NUL; p += 4)
+	    {
+		if (p[1] != ':' || p[2] == NUL || (p[3] != NUL && p[3] != ','))
+		{
+		    errmsg = e_invarg;
+		    break;
+		}
+		if (p[3] == NUL)
+		    break;
+	    }
+	}
+    }
+
+#ifdef FEAT_COMMENTS
+    // 'comments'
+    else if (gvarp == &p_com)
+    {
+	for (s = *varp; *s; )
+	{
+	    while (*s && *s != ':')
+	    {
+		if (vim_strchr((char_u *)COM_ALL, *s) == NULL
+					     && !VIM_ISDIGIT(*s) && *s != '-')
+		{
+		    errmsg = illegal_char(errbuf, *s);
+		    break;
+		}
+		++s;
+	    }
+	    if (*s++ == NUL)
+		errmsg = N_("E524: Missing colon");
+	    else if (*s == ',' || *s == NUL)
+		errmsg = N_("E525: Zero length string");
+	    if (errmsg != NULL)
+		break;
+	    while (*s && *s != ',')
+	    {
+		if (*s == '\\' && s[1] != NUL)
+		    ++s;
+		++s;
+	    }
+	    s = skip_to_option_part(s);
+	}
+    }
+#endif
+
+    // 'listchars'
+    else if (varp == &p_lcs)
+    {
+	errmsg = set_chars_option(varp);
+    }
+
+    // 'fillchars'
+    else if (varp == &p_fcs)
+    {
+	errmsg = set_chars_option(varp);
+    }
+
+#ifdef FEAT_CMDWIN
+    // 'cedit'
+    else if (varp == &p_cedit)
+    {
+	errmsg = check_cedit();
+    }
+#endif
+
+    // 'verbosefile'
+    else if (varp == &p_vfile)
+    {
+	verbose_stop();
+	if (*p_vfile != NUL && verbose_open() == FAIL)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_VIMINFO
+    // 'viminfo'
+    else if (varp == &p_viminfo)
+    {
+	for (s = p_viminfo; *s;)
+	{
+	    // Check it's a valid character
+	    if (vim_strchr((char_u *)"!\"%'/:<@cfhnrs", *s) == NULL)
+	    {
+		errmsg = illegal_char(errbuf, *s);
+		break;
+	    }
+	    if (*s == 'n')	// name is always last one
+		break;
+	    else if (*s == 'r') // skip until next ','
+	    {
+		while (*++s && *s != ',')
+		    ;
+	    }
+	    else if (*s == '%')
+	    {
+		// optional number
+		while (vim_isdigit(*++s))
+		    ;
+	    }
+	    else if (*s == '!' || *s == 'h' || *s == 'c')
+		++s;		// no extra chars
+	    else		// must have a number
+	    {
+		while (vim_isdigit(*++s))
+		    ;
+
+		if (!VIM_ISDIGIT(*(s - 1)))
+		{
+		    if (errbuf != NULL)
+		    {
+			sprintf(errbuf, _("E526: Missing number after <%s>"),
+						    transchar_byte(*(s - 1)));
+			errmsg = errbuf;
+		    }
+		    else
+			errmsg = "";
+		    break;
+		}
+	    }
+	    if (*s == ',')
+		++s;
+	    else if (*s)
+	    {
+		if (errbuf != NULL)
+		    errmsg = N_("E527: Missing comma");
+		else
+		    errmsg = "";
+		break;
+	    }
+	}
+	if (*p_viminfo && errmsg == NULL && get_viminfo_parameter('\'') < 0)
+	    errmsg = N_("E528: Must specify a ' value");
+    }
+#endif // FEAT_VIMINFO
+
+    // terminal options
+    else if (istermoption_idx(opt_idx) && full_screen)
+    {
+	// ":set t_Co=0" and ":set t_Co=1" do ":set t_Co="
+	if (varp == &T_CCO)
+	{
+	    int colors = atoi((char *)T_CCO);
+
+	    // Only reinitialize colors if t_Co value has really changed to
+	    // avoid expensive reload of colorscheme if t_Co is set to the
+	    // same value multiple times.
+	    if (colors != t_colors)
+	    {
+		t_colors = colors;
+		if (t_colors <= 1)
+		{
+		    if (new_value_alloced)
+			vim_free(T_CCO);
+		    T_CCO = empty_option;
+		}
+#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
+		if (is_term_win32())
+		{
+		    swap_tcap();
+		    did_swaptcap = TRUE;
+		}
+#endif
+		// We now have a different color setup, initialize it again.
+		init_highlight(TRUE, FALSE);
+	    }
+	}
+	ttest(FALSE);
+	if (varp == &T_ME)
+	{
+	    out_str(T_ME);
+	    redraw_later(CLEAR);
+#if defined(MSWIN) && (!defined(FEAT_GUI_MSWIN) || defined(VIMDLL))
+	    // Since t_me has been set, this probably means that the user
+	    // wants to use this as default colors.  Need to reset default
+	    // background/foreground colors.
+# ifdef VIMDLL
+	    if (!gui.in_use && !gui.starting)
+# endif
+		mch_set_normal_colors();
+#endif
+	}
+	if (varp == &T_BE && termcap_active)
+	{
+	    if (*T_BE == NUL)
+		// When clearing t_BE we assume the user no longer wants
+		// bracketed paste, thus disable it by writing t_BD.
+		out_str(T_BD);
+	    else
+		out_str(T_BE);
+	}
+    }
+
+#ifdef FEAT_LINEBREAK
+    // 'showbreak'
+    else if (varp == &p_sbr)
+    {
+	for (s = p_sbr; *s; )
+	{
+	    if (ptr2cells(s) != 1)
+		errmsg = N_("E595: contains unprintable or wide character");
+	    MB_PTR_ADV(s);
+	}
+    }
+#endif
+
+#ifdef FEAT_GUI
+    // 'guifont'
+    else if (varp == &p_guifont)
+    {
+	if (gui.in_use)
+	{
+	    p = p_guifont;
+# if defined(FEAT_GUI_GTK)
+	    // Put up a font dialog and let the user select a new value.
+	    // If this is cancelled go back to the old value but don't
+	    // give an error message.
+	    if (STRCMP(p, "*") == 0)
+	    {
+		p = gui_mch_font_dialog(oldval);
+
+		if (new_value_alloced)
+		    free_string_option(p_guifont);
+
+		p_guifont = (p != NULL) ? p : vim_strsave(oldval);
+		new_value_alloced = TRUE;
+	    }
+# endif
+	    if (p != NULL && gui_init_font(p_guifont, FALSE) != OK)
+	    {
+# if defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_PHOTON)
+		if (STRCMP(p_guifont, "*") == 0)
+		{
+		    // Dialog was cancelled: Keep the old value without giving
+		    // an error message.
+		    if (new_value_alloced)
+			free_string_option(p_guifont);
+		    p_guifont = vim_strsave(oldval);
+		    new_value_alloced = TRUE;
+		}
+		else
+# endif
+		    errmsg = N_("E596: Invalid font(s)");
+	    }
+	}
+	redraw_gui_only = TRUE;
+    }
+# ifdef FEAT_XFONTSET
+    else if (varp == &p_guifontset)
+    {
+	if (STRCMP(p_guifontset, "*") == 0)
+	    errmsg = N_("E597: can't select fontset");
+	else if (gui.in_use && gui_init_font(p_guifontset, TRUE) != OK)
+	    errmsg = N_("E598: Invalid fontset");
+	redraw_gui_only = TRUE;
+    }
+# endif
+    else if (varp == &p_guifontwide)
+    {
+	if (STRCMP(p_guifontwide, "*") == 0)
+	    errmsg = N_("E533: can't select wide font");
+	else if (gui_get_wide_font() == FAIL)
+	    errmsg = N_("E534: Invalid wide font");
+	redraw_gui_only = TRUE;
+    }
+#endif
+
+#ifdef CURSOR_SHAPE
+    // 'guicursor'
+    else if (varp == &p_guicursor)
+	errmsg = parse_shape_opt(SHAPE_CURSOR);
+#endif
+
+#ifdef FEAT_MOUSESHAPE
+    // 'mouseshape'
+    else if (varp == &p_mouseshape)
+    {
+	errmsg = parse_shape_opt(SHAPE_MOUSE);
+	update_mouseshape(-1);
+    }
+#endif
+
+#ifdef FEAT_PRINTER
+    else if (varp == &p_popt)
+	errmsg = parse_printoptions();
+# if defined(FEAT_POSTSCRIPT)
+    else if (varp == &p_pmfn)
+	errmsg = parse_printmbfont();
+# endif
+#endif
+
+#ifdef FEAT_LANGMAP
+    // 'langmap'
+    else if (varp == &p_langmap)
+	langmap_set();
+#endif
+
+#ifdef FEAT_LINEBREAK
+    // 'breakat'
+    else if (varp == &p_breakat)
+	fill_breakat_flags();
+#endif
+
+#ifdef FEAT_TITLE
+    // 'titlestring' and 'iconstring'
+    else if (varp == &p_titlestring || varp == &p_iconstring)
+    {
+# ifdef FEAT_STL_OPT
+	int	flagval = (varp == &p_titlestring) ? STL_IN_TITLE : STL_IN_ICON;
+
+	// NULL => statusline syntax
+	if (vim_strchr(*varp, '%') && check_stl_option(*varp) == NULL)
+	    stl_syntax |= flagval;
+	else
+	    stl_syntax &= ~flagval;
+# endif
+	did_set_title();
+    }
+#endif
+
+#ifdef FEAT_GUI
+    // 'guioptions'
+    else if (varp == &p_go)
+    {
+	gui_init_which_components(oldval);
+	redraw_gui_only = TRUE;
+    }
+#endif
+
+#if defined(FEAT_GUI_TABLINE)
+    // 'guitablabel'
+    else if (varp == &p_gtl)
+    {
+	redraw_tabline = TRUE;
+	redraw_gui_only = TRUE;
+    }
+    // 'guitabtooltip'
+    else if (varp == &p_gtt)
+    {
+	redraw_gui_only = TRUE;
+    }
+#endif
+
+#if defined(FEAT_MOUSE_TTY) && (defined(UNIX) || defined(VMS))
+    // 'ttymouse'
+    else if (varp == &p_ttym)
+    {
+	// Switch the mouse off before changing the escape sequences used for
+	// that.
+	mch_setmouse(FALSE);
+	if (opt_strings_flags(p_ttym, p_ttym_values, &ttym_flags, FALSE) != OK)
+	    errmsg = e_invarg;
+	else
+	    check_mouse_termcode();
+	if (termcap_active)
+	    setmouse();		// may switch it on again
+    }
+#endif
+
+    // 'selection'
+    else if (varp == &p_sel)
+    {
+	if (*p_sel == NUL
+		|| check_opt_strings(p_sel, p_sel_values, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'selectmode'
+    else if (varp == &p_slm)
+    {
+	if (check_opt_strings(p_slm, p_slm_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_BROWSE
+    // 'browsedir'
+    else if (varp == &p_bsdir)
+    {
+	if (check_opt_strings(p_bsdir, p_bsdir_values, FALSE) != OK
+		&& !mch_isdir(p_bsdir))
+	    errmsg = e_invarg;
+    }
+#endif
+
+    // 'keymodel'
+    else if (varp == &p_km)
+    {
+	if (check_opt_strings(p_km, p_km_values, TRUE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    km_stopsel = (vim_strchr(p_km, 'o') != NULL);
+	    km_startsel = (vim_strchr(p_km, 'a') != NULL);
+	}
+    }
+
+    // 'mousemodel'
+    else if (varp == &p_mousem)
+    {
+	if (check_opt_strings(p_mousem, p_mousem_values, FALSE) != OK)
+	    errmsg = e_invarg;
+#if defined(FEAT_GUI_MOTIF) && defined(FEAT_MENU) && (XmVersion <= 1002)
+	else if (*p_mousem != *oldval)
+	    // Changed from "extend" to "popup" or "popup_setpos" or vv: need
+	    // to create or delete the popup menus.
+	    gui_motif_update_mousemodel(root_menu);
+#endif
+    }
+
+    // 'switchbuf'
+    else if (varp == &p_swb)
+    {
+	if (opt_strings_flags(p_swb, p_swb_values, &swb_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'debug'
+    else if (varp == &p_debug)
+    {
+	if (check_opt_strings(p_debug, p_debug_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'display'
+    else if (varp == &p_dy)
+    {
+	if (opt_strings_flags(p_dy, p_dy_values, &dy_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+	else
+	    (void)init_chartab();
+
+    }
+
+    // 'eadirection'
+    else if (varp == &p_ead)
+    {
+	if (check_opt_strings(p_ead, p_ead_values, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_CLIPBOARD
+    // 'clipboard'
+    else if (varp == &p_cb)
+	errmsg = check_clipboard_option();
+#endif
+
+#ifdef FEAT_SPELL
+    // When 'spelllang' or 'spellfile' is set and there is a window for this
+    // buffer in which 'spell' is set load the wordlists.
+    else if (varp == &(curwin->w_s->b_p_spl)
+	    || varp == &(curwin->w_s->b_p_spf))
+    {
+	int	is_spellfile = varp == &(curwin->w_s->b_p_spf);
+
+	if ((is_spellfile && !valid_spellfile(*varp))
+	    || (!is_spellfile && !valid_spellang(*varp)))
+	    errmsg = e_invarg;
+	else
+	    errmsg = did_set_spell_option(is_spellfile);
+    }
+    // When 'spellcapcheck' is set compile the regexp program.
+    else if (varp == &(curwin->w_s->b_p_spc))
+    {
+	errmsg = compile_cap_prog(curwin->w_s);
+    }
+    // 'spellsuggest'
+    else if (varp == &p_sps)
+    {
+	if (spell_check_sps() != OK)
+	    errmsg = e_invarg;
+    }
+    // 'mkspellmem'
+    else if (varp == &p_msm)
+    {
+	if (spell_check_msm() != OK)
+	    errmsg = e_invarg;
+    }
+#endif
+
+    // When 'bufhidden' is set, check for valid value.
+    else if (gvarp == &p_bh)
+    {
+	if (check_opt_strings(curbuf->b_p_bh, p_bufhidden_values, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // When 'buftype' is set, check for valid value.
+    else if (gvarp == &p_bt)
+    {
+	if (check_opt_strings(curbuf->b_p_bt, p_buftype_values, FALSE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    if (curwin->w_status_height)
+	    {
+		curwin->w_redr_status = TRUE;
+		redraw_later(VALID);
+	    }
+	    curbuf->b_help = (curbuf->b_p_bt[0] == 'h');
+#ifdef FEAT_TITLE
+	    redraw_titles();
+#endif
+	}
+    }
+
+#ifdef FEAT_STL_OPT
+    // 'statusline' or 'rulerformat'
+    else if (gvarp == &p_stl || varp == &p_ruf)
+    {
+	int wid;
+
+	if (varp == &p_ruf)	// reset ru_wid first
+	    ru_wid = 0;
+	s = *varp;
+	if (varp == &p_ruf && *s == '%')
+	{
+	    // set ru_wid if 'ruf' starts with "%99("
+	    if (*++s == '-')	// ignore a '-'
+		s++;
+	    wid = getdigits(&s);
+	    if (wid && *s == '(' && (errmsg = check_stl_option(p_ruf)) == NULL)
+		ru_wid = wid;
+	    else
+		errmsg = check_stl_option(p_ruf);
+	}
+	// check 'statusline' only if it doesn't start with "%!"
+	else if (varp == &p_ruf || s[0] != '%' || s[1] != '!')
+	    errmsg = check_stl_option(s);
+	if (varp == &p_ruf && errmsg == NULL)
+	    comp_col();
+    }
+#endif
+
+    // check if it is a valid value for 'complete' -- Acevedo
+    else if (gvarp == &p_cpt)
+    {
+	for (s = *varp; *s;)
+	{
+	    while (*s == ',' || *s == ' ')
+		s++;
+	    if (!*s)
+		break;
+	    if (vim_strchr((char_u *)".wbuksid]tU", *s) == NULL)
+	    {
+		errmsg = illegal_char(errbuf, *s);
+		break;
+	    }
+	    if (*++s != NUL && *s != ',' && *s != ' ')
+	    {
+		if (s[-1] == 'k' || s[-1] == 's')
+		{
+		    // skip optional filename after 'k' and 's'
+		    while (*s && *s != ',' && *s != ' ')
+		    {
+			if (*s == '\\' && s[1] != NUL)
+			    ++s;
+			++s;
+		    }
+		}
+		else
+		{
+		    if (errbuf != NULL)
+		    {
+			sprintf((char *)errbuf,
+				     _("E535: Illegal character after <%c>"),
+				     *--s);
+			errmsg = errbuf;
+		    }
+		    else
+			errmsg = "";
+		    break;
+		}
+	    }
+	}
+    }
+
+    // 'completeopt'
+    else if (varp == &p_cot)
+    {
+	if (check_opt_strings(p_cot, p_cot_values, TRUE) != OK)
+	    errmsg = e_invarg;
+	else
+	    completeopt_was_set();
+    }
+
+#ifdef BACKSLASH_IN_FILENAME
+    // 'completeslash'
+    else if (gvarp == &p_csl)
+    {
+	if (check_opt_strings(p_csl, p_csl_values, FALSE) != OK
+		|| check_opt_strings(curbuf->b_p_csl, p_csl_values, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+#endif
+
+#ifdef FEAT_SIGNS
+    // 'signcolumn'
+    else if (varp == &curwin->w_p_scl)
+    {
+	if (check_opt_strings(*varp, p_scl_values, FALSE) != OK)
+	    errmsg = e_invarg;
+	// When changing the 'signcolumn' to or from 'number', recompute the
+	// width of the number column if 'number' or 'relativenumber' is set.
+	if (((*oldval == 'n' && *(oldval + 1) == 'u')
+		|| (*curwin->w_p_scl == 'n' && *(curwin->w_p_scl + 1) =='u'))
+		&& (curwin->w_p_nu || curwin->w_p_rnu))
+	    curwin->w_nrwidth_line_count = 0;
+    }
+#endif
+
+
+#if defined(FEAT_TOOLBAR) && !defined(FEAT_GUI_MSWIN)
+    // 'toolbar'
+    else if (varp == &p_toolbar)
+    {
+	if (opt_strings_flags(p_toolbar, p_toolbar_values,
+			      &toolbar_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    out_flush();
+	    gui_mch_show_toolbar((toolbar_flags &
+				  (TOOLBAR_TEXT | TOOLBAR_ICONS)) != 0);
+	}
+    }
+#endif
+
+#if defined(FEAT_TOOLBAR) && defined(FEAT_GUI_GTK)
+    // 'toolbariconsize': GTK+ 2 only
+    else if (varp == &p_tbis)
+    {
+	if (opt_strings_flags(p_tbis, p_tbis_values, &tbis_flags, FALSE) != OK)
+	    errmsg = e_invarg;
+	else
+	{
+	    out_flush();
+	    gui_mch_show_toolbar((toolbar_flags &
+				  (TOOLBAR_TEXT | TOOLBAR_ICONS)) != 0);
+	}
+    }
+#endif
+
+    // 'pastetoggle': translate key codes like in a mapping
+    else if (varp == &p_pt)
+    {
+	if (*p_pt)
+	{
+	    (void)replace_termcodes(p_pt, &p, TRUE, TRUE, FALSE);
+	    if (p != NULL)
+	    {
+		if (new_value_alloced)
+		    free_string_option(p_pt);
+		p_pt = p;
+		new_value_alloced = TRUE;
+	    }
+	}
+    }
+
+    // 'backspace'
+    else if (varp == &p_bs)
+    {
+	if (VIM_ISDIGIT(*p_bs))
+	{
+	    if (*p_bs > '2' || p_bs[1] != NUL)
+		errmsg = e_invarg;
+	}
+	else if (check_opt_strings(p_bs, p_bs_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+    else if (varp == &p_bo)
+    {
+	if (opt_strings_flags(p_bo, p_bo_values, &bo_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'tagcase'
+    else if (gvarp == &p_tc)
+    {
+	unsigned int	*flags;
+
+	if (opt_flags & OPT_LOCAL)
+	{
+	    p = curbuf->b_p_tc;
+	    flags = &curbuf->b_tc_flags;
+	}
+	else
+	{
+	    p = p_tc;
+	    flags = &tc_flags;
+	}
+
+	if ((opt_flags & OPT_LOCAL) && *p == NUL)
+	    // make the local value empty: use the global value
+	    *flags = 0;
+	else if (*p == NUL
+		|| opt_strings_flags(p, p_tc_values, flags, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+
+    // 'casemap'
+    else if (varp == &p_cmp)
+    {
+	if (opt_strings_flags(p_cmp, p_cmp_values, &cmp_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+
+#ifdef FEAT_DIFF
+    // 'diffopt'
+    else if (varp == &p_dip)
+    {
+	if (diffopt_changed() == FAIL)
+	    errmsg = e_invarg;
+    }
+#endif
+
+#ifdef FEAT_FOLDING
+    // 'foldmethod'
+    else if (gvarp == &curwin->w_allbuf_opt.wo_fdm)
+    {
+	if (check_opt_strings(*varp, p_fdm_values, FALSE) != OK
+		|| *curwin->w_p_fdm == NUL)
+	    errmsg = e_invarg;
+	else
+	{
+	    foldUpdateAll(curwin);
+	    if (foldmethodIsDiff(curwin))
+		newFoldLevel();
+	}
+    }
+# ifdef FEAT_EVAL
+    // 'foldexpr'
+    else if (varp == &curwin->w_p_fde)
+    {
+	if (foldmethodIsExpr(curwin))
+	    foldUpdateAll(curwin);
+    }
+# endif
+    // 'foldmarker'
+    else if (gvarp == &curwin->w_allbuf_opt.wo_fmr)
+    {
+	p = vim_strchr(*varp, ',');
+	if (p == NULL)
+	    errmsg = N_("E536: comma required");
+	else if (p == *varp || p[1] == NUL)
+	    errmsg = e_invarg;
+	else if (foldmethodIsMarker(curwin))
+	    foldUpdateAll(curwin);
+    }
+    // 'commentstring'
+    else if (gvarp == &p_cms)
+    {
+	if (**varp != NUL && strstr((char *)*varp, "%s") == NULL)
+	    errmsg = N_("E537: 'commentstring' must be empty or contain %s");
+    }
+    // 'foldopen'
+    else if (varp == &p_fdo)
+    {
+	if (opt_strings_flags(p_fdo, p_fdo_values, &fdo_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+    // 'foldclose'
+    else if (varp == &p_fcl)
+    {
+	if (check_opt_strings(p_fcl, p_fcl_values, TRUE) != OK)
+	    errmsg = e_invarg;
+    }
+    // 'foldignore'
+    else if (gvarp == &curwin->w_allbuf_opt.wo_fdi)
+    {
+	if (foldmethodIsIndent(curwin))
+	    foldUpdateAll(curwin);
+    }
+#endif
+
+    // 'virtualedit'
+    else if (varp == &p_ve)
+    {
+	if (opt_strings_flags(p_ve, p_ve_values, &ve_flags, TRUE) != OK)
+	    errmsg = e_invarg;
+	else if (STRCMP(p_ve, oldval) != 0)
+	{
+	    // Recompute cursor position in case the new 've' setting
+	    // changes something.
+	    validate_virtcol();
+	    coladvance(curwin->w_virtcol);
+	}
+    }
+
+#if defined(FEAT_CSCOPE) && defined(FEAT_QUICKFIX)
+    else if (varp == &p_csqf)
+    {
+	if (p_csqf != NULL)
+	{
+	    p = p_csqf;
+	    while (*p != NUL)
+	    {
+		if (vim_strchr((char_u *)CSQF_CMDS, *p) == NULL
+			|| p[1] == NUL
+			|| vim_strchr((char_u *)CSQF_FLAGS, p[1]) == NULL
+			|| (p[2] != NUL && p[2] != ','))
+		{
+		    errmsg = e_invarg;
+		    break;
+		}
+		else if (p[2] == NUL)
+		    break;
+		else
+		    p += 3;
+	    }
+	}
+    }
+#endif
+
+#ifdef FEAT_CINDENT
+    // 'cinoptions'
+    else if (gvarp == &p_cino)
+    {
+	// TODO: recognize errors
+	parse_cino(curbuf);
+    }
+#endif
+
+#if defined(FEAT_RENDER_OPTIONS)
+    // 'renderoptions'
+    else if (varp == &p_rop)
+    {
+	if (!gui_mch_set_rendering_options(p_rop))
+	    errmsg = e_invarg;
+    }
+#endif
+
+    else if (gvarp == &p_ft)
+    {
+	if (!valid_filetype(*varp))
+	    errmsg = e_invarg;
+	else
+	{
+	    value_changed = STRCMP(oldval, *varp) != 0;
+
+	    // Since we check the value, there is no need to set P_INSECURE,
+	    // even when the value comes from a modeline.
+	    *value_checked = TRUE;
+	}
+    }
+
+#ifdef FEAT_SYN_HL
+    else if (gvarp == &p_syn)
+    {
+	if (!valid_filetype(*varp))
+	    errmsg = e_invarg;
+	else
+	{
+	    value_changed = STRCMP(oldval, *varp) != 0;
+
+	    // Since we check the value, there is no need to set P_INSECURE,
+	    // even when the value comes from a modeline.
+	    *value_checked = TRUE;
+	}
+    }
+#endif
+
+#ifdef FEAT_TERMINAL
+    // 'termwinkey'
+    else if (varp == &curwin->w_p_twk)
+    {
+	if (*curwin->w_p_twk != NUL
+				  && string_to_key(curwin->w_p_twk, TRUE) == 0)
+	    errmsg = e_invarg;
+    }
+    // 'termwinsize'
+    else if (varp == &curwin->w_p_tws)
+    {
+	if (*curwin->w_p_tws != NUL)
+	{
+	    p = skipdigits(curwin->w_p_tws);
+	    if (p == curwin->w_p_tws
+		    || (*p != 'x' && *p != '*')
+		    || *skipdigits(p + 1) != NUL)
+		errmsg = e_invarg;
+	}
+    }
+# if defined(MSWIN)
+    // 'termwintype'
+    else if (varp == &p_twt)
+    {
+	if (check_opt_strings(*varp, p_twt_values, FALSE) != OK)
+	    errmsg = e_invarg;
+    }
+# endif
+#endif
+
+#ifdef FEAT_VARTABS
+    // 'varsofttabstop'
+    else if (varp == &(curbuf->b_p_vsts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vsts_array)
+	    {
+		vim_free(curbuf->b_p_vsts_array);
+		curbuf->b_p_vsts_array = 0;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vsts_array;
+		if (tabstop_set(*varp, &(curbuf->b_p_vsts_array)))
+		{
+		    if (oldarray)
+			vim_free(oldarray);
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+
+    // 'vartabstop'
+    else if (varp == &(curbuf->b_p_vts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vts_array)
+	    {
+		vim_free(curbuf->b_p_vts_array);
+		curbuf->b_p_vts_array = NULL;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vts_array;
+
+		if (tabstop_set(*varp, &(curbuf->b_p_vts_array)))
+		{
+		    vim_free(oldarray);
+#ifdef FEAT_FOLDING
+		    if (foldmethodIsIndent(curwin))
+			foldUpdateAll(curwin);
+#endif
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+#endif
+
+#ifdef FEAT_TEXT_PROP
+    // 'previewpopup'
+    else if (varp == &p_pvp)
+    {
+	if (parse_previewpopup(NULL) == FAIL)
+	    errmsg = e_invarg;
+    }
+# ifdef FEAT_QUICKFIX
+    // 'completepopup'
+    else if (varp == &p_cpp)
+    {
+	if (parse_completepopup(NULL) == FAIL)
+	    errmsg = e_invarg;
+    }
+# endif
+#endif
+
+    // Options that are a list of flags.
+    else
+    {
+	p = NULL;
+	if (varp == &p_ww) // 'whichwrap'
+	    p = (char_u *)WW_ALL;
+	if (varp == &p_shm) // 'shortmess'
+	    p = (char_u *)SHM_ALL;
+	else if (varp == &(p_cpo)) // 'cpoptions'
+	    p = (char_u *)CPO_ALL;
+	else if (varp == &(curbuf->b_p_fo)) // 'formatoptions'
+	    p = (char_u *)FO_ALL;
+#ifdef FEAT_CONCEAL
+	else if (varp == &curwin->w_p_cocu) // 'concealcursor'
+	    p = (char_u *)COCU_ALL;
+#endif
+	else if (varp == &p_mouse) // 'mouse'
+	{
+#ifdef FEAT_MOUSE
+	    p = (char_u *)MOUSE_ALL;
+#else
+	    if (*p_mouse != NUL)
+		errmsg = N_("E538: No mouse support");
+#endif
+	}
+#if defined(FEAT_GUI)
+	else if (varp == &p_go) // 'guioptions'
+	    p = (char_u *)GO_ALL;
+#endif
+	if (p != NULL)
+	{
+	    for (s = *varp; *s; ++s)
+		if (vim_strchr(p, *s) == NULL)
+		{
+		    errmsg = illegal_char(errbuf, *s);
+		    break;
+		}
+	}
+    }
+
+    // If error detected, restore the previous value.
+    if (errmsg != NULL)
+    {
+	if (new_value_alloced)
+	    free_string_option(*varp);
+	*varp = oldval;
+	// When resetting some values, need to act on it.
+	if (did_chartab)
+	    (void)init_chartab();
+	if (varp == &p_hl)
+	    (void)highlight_changed();
+    }
+    else
+    {
+#ifdef FEAT_EVAL
+	// Remember where the option was set.
+	set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
+#endif
+	// Free string options that are in allocated memory.
+	// Use "free_oldval", because recursiveness may change the flags under
+	// our fingers (esp. init_highlight()).
+	if (free_oldval)
+	    free_string_option(oldval);
+	if (new_value_alloced)
+	    set_option_flag(opt_idx, P_ALLOCED);
+	else
+	    clear_option_flag(opt_idx, P_ALLOCED);
+
+	if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
+		&& is_global_local_option(opt_idx))
+	{
+	    // global option with local value set to use global value; free
+	    // the local value and make it empty
+	    p = get_option_varp_scope(opt_idx, OPT_LOCAL);
+	    free_string_option(*(char_u **)p);
+	    *(char_u **)p = empty_option;
+	}
+
+	// May set global value for local option.
+	else if (!(opt_flags & OPT_LOCAL) && opt_flags != OPT_GLOBAL)
+	    set_string_option_global(opt_idx, varp);
+
+	// Trigger the autocommand only after setting the flags.
+#ifdef FEAT_SYN_HL
+	// When 'syntax' is set, load the syntax of that name
+	if (varp == &(curbuf->b_p_syn))
+	{
+	    static int syn_recursive = 0;
+
+	    ++syn_recursive;
+	    // Only pass TRUE for "force" when the value changed or not used
+	    // recursively, to avoid endless recurrence.
+	    apply_autocmds(EVENT_SYNTAX, curbuf->b_p_syn, curbuf->b_fname,
+		    value_changed || syn_recursive == 1, curbuf);
+	    curbuf->b_flags |= BF_SYN_SET;
+	    --syn_recursive;
+	}
+#endif
+	else if (varp == &(curbuf->b_p_ft))
+	{
+	    // 'filetype' is set, trigger the FileType autocommand.
+	    // Skip this when called from a modeline and the filetype was
+	    // already set to this value.
+	    if (!(opt_flags & OPT_MODELINE) || value_changed)
+	    {
+		static int  ft_recursive = 0;
+		int	    secure_save = secure;
+
+		// Reset the secure flag, since the value of 'filetype' has
+		// been checked to be safe.
+		secure = 0;
+
+		++ft_recursive;
+		did_filetype = TRUE;
+		// Only pass TRUE for "force" when the value changed or not
+		// used recursively, to avoid endless recurrence.
+		apply_autocmds(EVENT_FILETYPE, curbuf->b_p_ft, curbuf->b_fname,
+				   value_changed || ft_recursive == 1, curbuf);
+		--ft_recursive;
+		// Just in case the old "curbuf" is now invalid.
+		if (varp != &(curbuf->b_p_ft))
+		    varp = NULL;
+
+		secure = secure_save;
+	    }
+	}
+#ifdef FEAT_SPELL
+	if (varp == &(curwin->w_s->b_p_spl))
+	{
+	    char_u	fname[200];
+	    char_u	*q = curwin->w_s->b_p_spl;
+
+	    // Skip the first name if it is "cjk".
+	    if (STRNCMP(q, "cjk,", 4) == 0)
+		q += 4;
+
+	    // Source the spell/LANG.vim in 'runtimepath'.
+	    // They could set 'spellcapcheck' depending on the language.
+	    // Use the first name in 'spelllang' up to '_region' or
+	    // '.encoding'.
+	    for (p = q; *p != NUL; ++p)
+		if (!ASCII_ISALNUM(*p) && *p != '-')
+		    break;
+	    if (p > q)
+	    {
+		vim_snprintf((char *)fname, 200, "spell/%.*s.vim",
+							      (int)(p - q), q);
+		source_runtime(fname, DIP_ALL);
+	    }
+	}
+#endif
+    }
+
+#ifdef FEAT_MOUSE
+    if (varp == &p_mouse)
+    {
+# ifdef FEAT_MOUSE_TTY
+	if (*p_mouse == NUL)
+	    mch_setmouse(FALSE);    // switch mouse off
+	else
+# endif
+	    setmouse();		    // in case 'mouse' changed
+    }
+#endif
+
+    if (curwin->w_curswant != MAXCOL
+		     && (get_option_flags(opt_idx) & (P_CURSWANT | P_RALL)) != 0)
+	curwin->w_set_curswant = TRUE;
+
+#ifdef FEAT_GUI
+    // check redraw when it's not a GUI option or the GUI is active.
+    if (!redraw_gui_only || gui.in_use)
+#endif
+	check_redraw(get_option_flags(opt_idx));
+
+#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
+    if (did_swaptcap)
+    {
+	set_termname((char_u *)"win32");
+	init_highlight(TRUE, FALSE);
+    }
+#endif
+
+    return errmsg;
+}
+
+/*
+ * Check an option that can be a range of string values.
+ *
+ * Return OK for correct value, FAIL otherwise.
+ * Empty is always OK.
+ */
+    static int
+check_opt_strings(
+    char_u	*val,
+    char	**values,
+    int		list)	    // when TRUE: accept a list of values
+{
+    return opt_strings_flags(val, values, NULL, list);
+}
+
+/*
+ * Handle an option that can be a range of string values.
+ * Set a flag in "*flagp" for each string present.
+ *
+ * Return OK for correct value, FAIL otherwise.
+ * Empty is always OK.
+ */
+    static int
+opt_strings_flags(
+    char_u	*val,		// new value
+    char	**values,	// array of valid string values
+    unsigned	*flagp,
+    int		list)		// when TRUE: accept a list of values
+{
+    int		i;
+    int		len;
+    unsigned	new_flags = 0;
+
+    while (*val)
+    {
+	for (i = 0; ; ++i)
+	{
+	    if (values[i] == NULL)	// val not found in values[]
+		return FAIL;
+
+	    len = (int)STRLEN(values[i]);
+	    if (STRNCMP(values[i], val, len) == 0
+		    && ((list && val[len] == ',') || val[len] == NUL))
+	    {
+		val += len + (val[len] == ',');
+		new_flags |= (1 << i);
+		break;		// check next item in val list
+	    }
+	}
+    }
+    if (flagp != NULL)
+	*flagp = new_flags;
+
+    return OK;
+}
+
+/*
+ * return OK if "p" is a valid fileformat name, FAIL otherwise.
+ */
+    int
+check_ff_value(char_u *p)
+{
+    return check_opt_strings(p, p_ff_values, FALSE);
+}
diff --git a/src/os_unix.c b/src/os_unix.c
index 2851459..54989af 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -135,7 +135,7 @@
 
 static char_u	*oldtitle = NULL;
 static volatile sig_atomic_t oldtitle_outdated = FALSE;
-static int	did_set_title = FALSE;
+static int	unix_did_set_title = FALSE;
 static char_u	*oldicon = NULL;
 static int	did_set_icon = FALSE;
 #endif
@@ -2187,7 +2187,7 @@
 	else
 	    gui_mch_settitle(title, icon);
 #endif
-	did_set_title = TRUE;
+	unix_did_set_title = TRUE;
     }
 
     if ((type || *T_CIS != NUL) && icon != NULL)
@@ -2228,10 +2228,10 @@
     void
 mch_restore_title(int which)
 {
-    int	do_push_pop = did_set_title || did_set_icon;
+    int	do_push_pop = unix_did_set_title || did_set_icon;
 
     /* only restore the title or icon when it has been set */
-    mch_settitle(((which & SAVE_RESTORE_TITLE) && did_set_title) ?
+    mch_settitle(((which & SAVE_RESTORE_TITLE) && unix_did_set_title) ?
 			(oldtitle ? oldtitle : p_titleold) : NULL,
 	       ((which & SAVE_RESTORE_ICON) && did_set_icon) ? oldicon : NULL);
 
diff --git a/src/proto.h b/src/proto.h
index c301857..842d891 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -178,6 +178,7 @@
 # include "normal.pro"
 # include "ops.pro"
 # include "option.pro"
+# include "optionstr.pro"
 # include "popupmnu.pro"
 # if defined(FEAT_PROFILE) || defined(FEAT_RELTIME)
 # include "profiler.pro"
diff --git a/src/proto/option.pro b/src/proto/option.pro
index e842484..d6c8558 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -10,22 +10,32 @@
 void init_gui_options(void);
 void set_title_defaults(void);
 int do_set(char_u *arg, int opt_flags);
+void did_set_option(int opt_idx, int opt_flags, int new_value, int value_checked);
 int string_to_key(char_u *arg, int multi_byte);
+char *check_cedit(void);
+void did_set_title(void);
 void set_options_bin(int oldval, int newval, int opt_flags);
 void check_options(void);
-void check_buf_options(buf_T *buf);
-void free_string_option(char_u *p);
-void clear_string_option(char_u **pp);
 int get_term_opt_idx(char_u **p);
 int set_term_option_alloced(char_u **p);
 int was_set_insecurely(char_u *opt, int opt_flags);
-void set_string_option_direct(char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
-void set_string_option_direct_in_win(win_T *wp, char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
-void set_string_option_direct_in_buf(buf_T *buf, char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
+void redraw_titles(void);
 int valid_name(char_u *val, char *allowed);
+char *check_clipboard_option(void);
+void set_option_sctx_idx(int opt_idx, int opt_flags, sctx_T script_ctx);
 void set_term_option_sctx_idx(char *name, int opt_idx);
+void check_redraw(long_u flags);
+int findoption(char_u *arg);
 int get_option_value(char_u *name, long *numval, char_u **stringval, int opt_flags);
 int get_option_value_strict(char_u *name, long *numval, char_u **stringval, int opt_type, void *from);
+long_u get_option_flags(int opt_idx);
+void set_option_flag(int opt_idx, long_u flag);
+void clear_option_flag(int opt_idx, long_u flag);
+int is_global_option(int opt_idx);
+int is_global_local_option(int opt_idx);
+int is_window_local_option(int opt_idx);
+int is_hidden_option(int opt_idx);
+int is_crypt_key_option(int opt_idx);
 char_u *option_iter_next(void **option, int opt_type);
 char *set_option_value(char_u *name, long number, char_u *string, int opt_flags);
 char_u *get_term_code(char_u *tname);
@@ -37,7 +47,11 @@
 void free_termoptions(void);
 void free_one_termoption(char_u *var);
 void set_term_defaults(void);
+int istermoption_idx(int opt_idx);
 void unset_global_local_option(char_u *name, void *from);
+char_u *get_option_varp_scope(int opt_idx, int opt_flags);
+char_u *get_option_var(int opt_idx);
+char_u *get_option_fullname(int opt_idx);
 char_u *get_equalprg(void);
 void win_copy_options(win_T *wp_from, win_T *wp_to);
 void copy_winopt(winopt_T *from, winopt_T *to);
@@ -55,10 +69,11 @@
 void change_compatible(int on);
 int option_was_set(char_u *name);
 int reset_option_was_set(char_u *name);
+void fill_breakat_flags(void);
+int check_opt_wim(void);
 int can_bs(int what);
 void save_file_ff(buf_T *buf);
 int file_ff_differs(buf_T *buf, int ignore_empty);
-int check_ff_value(char_u *p);
 int tabstop_set(char_u *var, int **array);
 int tabstop_padding(colnr_T col, int ts_arg, int *vts);
 int tabstop_at(colnr_T col, int ts, int *vts);
@@ -75,7 +90,9 @@
 long get_scrolloff_value(void);
 long get_sidescrolloff_value(void);
 void find_mps_values(int *initc, int *findc, int *backwards, int switchit);
+int briopt_check(win_T *wp);
 unsigned int get_bkc_value(buf_T *buf);
 int signcolumn_on(win_T *wp);
 dict_T *get_winbuf_options(int bufopt);
+int fill_culopt_flags(char_u *val, win_T *wp);
 /* vim: set ft=c : */
diff --git a/src/proto/optionstr.pro b/src/proto/optionstr.pro
new file mode 100644
index 0000000..dc1079e
--- /dev/null
+++ b/src/proto/optionstr.pro
@@ -0,0 +1,14 @@
+/* optionstr.c */
+void didset_string_options(void);
+void trigger_optionsset_string(int opt_idx, int opt_flags, char_u *oldval, char_u *oldval_l, char_u *oldval_g, char_u *newval);
+char *did_set_string_option(int opt_idx, char_u **varp, int new_value_alloced, char_u *oldval, char *errbuf, int opt_flags, int *value_checked);
+void check_buf_options(buf_T *buf);
+void free_string_option(char_u *p);
+void clear_string_option(char_u **pp);
+void check_string_option(char_u **pp);
+void set_string_option_direct(char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
+void set_string_option_direct_in_win(win_T *wp, char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
+void set_string_option_direct_in_buf(buf_T *buf, char_u *name, int opt_idx, char_u *val, int opt_flags, int set_sid);
+char *set_string_option(int opt_idx, char_u *value, int opt_flags);
+int check_ff_value(char_u *p);
+/* vim: set ft=c : */
diff --git a/src/version.c b/src/version.c
index c23fc83..34e3e6b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2045,
+/**/
     2044,
 /**/
     2043,