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;