diff --git a/src/option.c b/src/option.c
index 1203180..7435467 100644
--- a/src/option.c
+++ b/src/option.c
@@ -66,7 +66,6 @@
 static void option_value2string(struct vimoption *, int scope);
 static void check_winopt(winopt_T *wop);
 static int wc_use_keyname(char_u *varp, long *wcp);
-static void paste_option_changed(void);
 static void compatible_set(void);
 
 /*
@@ -3111,556 +3110,6 @@
 }
 #endif
 
-/*
- * Process the updated 'compatible' option value.
- */
-    char *
-did_set_compatible(optset_T *args UNUSED)
-{
-    compatible_set();
-    return NULL;
-}
-
-#if defined(FEAT_LANGMAP) || defined(PROTO)
-/*
- * Process the updated 'langremap' option value.
- */
-    char *
-did_set_langremap(optset_T *args UNUSED)
-{
-    // 'langremap' -> !'langnoremap'
-    p_lnr = !p_lrm;
-    return NULL;
-}
-
-/*
- * Process the updated 'langnoremap' option value.
- */
-    char *
-did_set_langnoremap(optset_T *args UNUSED)
-{
-    // 'langnoremap' -> !'langremap'
-    p_lrm = !p_lnr;
-    return NULL;
-}
-#endif
-
-#if defined(FEAT_PERSISTENT_UNDO) || defined(PROTO)
-/*
- * Process the updated 'undofile' option value.
- */
-    char *
-did_set_undofile(optset_T *args)
-{
-    // Only take action when the option was set.
-    if (!curbuf->b_p_udf && !p_udf)
-	return NULL;
-
-    // When reset we do not delete the undo file, the option may be set again
-    // without making any changes in between.
-    char_u	hash[UNDO_HASH_SIZE];
-    buf_T	*save_curbuf = curbuf;
-
-    FOR_ALL_BUFFERS(curbuf)
-    {
-	// When 'undofile' is set globally: for every buffer, otherwise
-	// only for the current buffer: Try to read in the undofile,
-	// if one exists, the buffer wasn't changed and the buffer was
-	// loaded
-	if ((curbuf == save_curbuf
-		    || (args->os_flags & OPT_GLOBAL)
-		    || args->os_flags == 0)
-		&& !curbufIsChanged() && curbuf->b_ml.ml_mfp != NULL)
-	{
-#ifdef FEAT_CRYPT
-	    if (crypt_get_method_nr(curbuf) == CRYPT_M_SOD)
-		continue;
-#endif
-	    u_compute_hash(hash);
-	    u_read_undo(NULL, hash, curbuf->b_fname);
-	}
-    }
-    curbuf = save_curbuf;
-
-    return NULL;
-}
-#endif
-
-/*
- * Process the updated 'readonly' option value.
- */
-    char *
-did_set_readonly(optset_T *args)
-{
-    // when 'readonly' is reset globally, also reset readonlymode
-    if (!curbuf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0)
-	readonlymode = FALSE;
-
-    // when 'readonly' is set may give W10 again
-    if (curbuf->b_p_ro)
-	curbuf->b_did_warn = FALSE;
-
-    redraw_titles();
-
-    return NULL;
-}
-
-#if defined(FEAT_GUI) || defined(PROTO)
-/*
- * Process the updated 'mousehide' option value.
- */
-    char *
-did_set_mousehide(optset_T *args UNUSED)
-{
-    if (!p_mh)
-	gui_mch_mousehide(FALSE);
-    return NULL;
-}
-#endif
-
-/*
- * Process the updated 'modifiable' option value.
- */
-    char *
-did_set_modifiable(optset_T *args UNUSED)
-{
-    // when 'modifiable' is changed, redraw the window title
-
-# ifdef FEAT_TERMINAL
-    // Cannot set 'modifiable' when in Terminal mode.
-    if (curbuf->b_p_ma && (term_in_normal_mode() || (bt_terminal(curbuf)
-		    && curbuf->b_term != NULL && !term_is_finished(curbuf))))
-    {
-	curbuf->b_p_ma = FALSE;
-	args->os_doskip = TRUE;
-	return e_cannot_make_terminal_with_running_job_modifiable;
-    }
-# endif
-    redraw_titles();
-
-    return NULL;
-}
-
-/*
- * Process the updated 'endoffile' or 'endofline' or 'fixendofline' or 'bomb'
- * option value.
- */
-    char *
-did_set_eof_eol_fixeol_bomb(optset_T *args UNUSED)
-{
-    // redraw the window title and tab page text
-    redraw_titles();
-    return NULL;
-}
-
-/*
- * Process the updated 'binary' option value.
- */
-    char *
-did_set_binary(optset_T *args)
-{
-    // when 'bin' is set also set some other options
-    set_options_bin(args->os_oldval.boolean, curbuf->b_p_bin, args->os_flags);
-    redraw_titles();
-
-    return NULL;
-}
-
-/*
- * Process the updated 'buflisted' option value.
- */
-    char *
-did_set_buflisted(optset_T *args)
-{
-    // when 'buflisted' changes, trigger autocommands
-    if (args->os_oldval.boolean != curbuf->b_p_bl)
-	apply_autocmds(curbuf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
-						NULL, NULL, TRUE, curbuf);
-    return NULL;
-}
-
-/*
- * Process the updated 'swapfile' option value.
- */
-    char *
-did_set_swapfile(optset_T *args UNUSED)
-{
-    // when 'swf' is set, create swapfile, when reset remove swapfile
-    if (curbuf->b_p_swf && p_uc)
-	ml_open_file(curbuf);		// create the swap file
-    else
-	// no need to reset curbuf->b_may_swap, ml_open_file() will check
-	// buf->b_p_swf
-	mf_close_file(curbuf, TRUE);	// remove the swap file
-    return NULL;
-}
-
-/*
- * Process the updated 'terse' option value.
- */
-    char *
-did_set_terse(optset_T *args UNUSED)
-{
-    char_u	*p;
-
-    // when 'terse' is set change 'shortmess'
-    p = vim_strchr(p_shm, SHM_SEARCH);
-
-    // insert 's' in p_shm
-    if (p_terse && p == NULL)
-    {
-	STRCPY(IObuff, p_shm);
-	STRCAT(IObuff, "s");
-	set_string_option_direct((char_u *)"shm", -1, IObuff, OPT_FREE, 0);
-    }
-    // remove 's' from p_shm
-    else if (!p_terse && p != NULL)
-	STRMOVE(p, p + 1);
-    return NULL;
-}
-
-/*
- * Process the updated 'paste' option value.
- */
-    char *
-did_set_paste(optset_T *args UNUSED)
-{
-    // when 'paste' is set or reset also change other options
-    paste_option_changed();
-    return NULL;
-}
-
-/*
- * Process the updated 'insertmode' option value.
- */
-    char *
-did_set_insertmode(optset_T *args)
-{
-    // when 'insertmode' is set from an autocommand need to do work here
-    if (p_im)
-    {
-	if ((State & MODE_INSERT) == 0)
-	    need_start_insertmode = TRUE;
-	stop_insert_mode = FALSE;
-    }
-    // only reset if it was set previously
-    else if (args->os_oldval.boolean)
-    {
-	need_start_insertmode = FALSE;
-	stop_insert_mode = TRUE;
-	if (restart_edit != 0 && mode_displayed)
-	    clear_cmdline = TRUE;	// remove "(insert)"
-	restart_edit = 0;
-    }
-
-    return NULL;
-}
-
-/*
- * Process the updated 'ignorecase' option value.
- */
-    char *
-did_set_ignorecase(optset_T *args UNUSED)
-{
-    // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
-    if (p_hls)
-	redraw_all_later(UPD_SOME_VALID);
-    return NULL;
-}
-
-#if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
-/*
- * Process the updated 'hlsearch' option value.
- */
-    char *
-did_set_hlsearch(optset_T *args UNUSED)
-{
-    // when 'hlsearch' is set or reset: reset no_hlsearch
-    set_no_hlsearch(FALSE);
-    return NULL;
-}
-#endif
-
-/*
- * Process the updated 'scrollbind' option value.
- */
-    char *
-did_set_scrollbind(optset_T *args UNUSED)
-{
-    // when 'scrollbind' is set: snapshot the current position to avoid a jump
-    // at the end of normal_cmd()
-    if (!curwin->w_p_scb)
-	return NULL;
-
-    do_check_scrollbind(FALSE);
-    curwin->w_scbind_pos = curwin->w_topline;
-    return NULL;
-}
-
-#ifdef FEAT_QUICKFIX
-/*
- * Process the updated 'previewwindow' option value.
- */
-    char *
-did_set_previewwindow(optset_T *args)
-{
-    if (!curwin->w_p_pvw)
-	return NULL;
-
-    // There can be only one window with 'previewwindow' set.
-    win_T	*win;
-
-    FOR_ALL_WINDOWS(win)
-	if (win->w_p_pvw && win != curwin)
-	{
-	    curwin->w_p_pvw = FALSE;
-	    args->os_doskip = TRUE;
-	    return e_preview_window_already_exists;
-	}
-
-    return NULL;
-}
-#endif
-
-/*
- * Process the updated 'smoothscroll' option value.
- */
-    char *
-did_set_smoothscroll(optset_T *args UNUSED)
-{
-    if (curwin->w_p_sms)
-	return NULL;
-
-    curwin->w_skipcol = 0;
-    changed_line_abv_curs();
-    return NULL;
-}
-
-/*
- * Process the updated 'textmode' option value.
- */
-    char *
-did_set_textmode(optset_T *args)
-{
-    // when 'textmode' is set or reset also change 'fileformat'
-    set_fileformat(curbuf->b_p_tx ? EOL_DOS : EOL_UNIX, args->os_flags);
-
-    return NULL;
-}
-
-/*
- * Process the updated 'textauto' option value.
- */
-    char *
-did_set_textauto(optset_T *args)
-{
-    // when 'textauto' is set or reset also change 'fileformats'
-    set_string_option_direct((char_u *)"ffs", -1,
-				p_ta ? (char_u *)DFLT_FFS_VIM : (char_u *)"",
-				OPT_FREE | args->os_flags, 0);
-
-    return NULL;
-}
-
-/*
- * Process the updated 'lisp' option value.
- */
-    char *
-did_set_lisp(optset_T *args UNUSED)
-{
-    // When 'lisp' option changes include/exclude '-' in keyword characters.
-    (void)buf_init_chartab(curbuf, FALSE);	    // ignore errors
-    return NULL;
-}
-
-/*
- * Process the updated 'title' or the 'icon' option value.
- */
-    char *
-did_set_title_icon(optset_T *args UNUSED)
-{
-    // when 'title' changed, may need to change the title; same for 'icon'
-    did_set_title();
-    return NULL;
-}
-
-/*
- * Process the updated 'modified' option value.
- */
-    char *
-did_set_modified(optset_T *args)
-{
-    if (!args->os_newval.boolean)
-	save_file_ff(curbuf);	// Buffer is unchanged
-    redraw_titles();
-    modified_was_set = args->os_newval.boolean;
-    return NULL;
-}
-
-#if defined(BACKSLASH_IN_FILENAME) || defined(PROTO)
-/*
- * Process the updated 'shellslash' option value.
- */
-    char *
-did_set_shellslash(optset_T *args UNUSED)
-{
-    if (p_ssl)
-    {
-	psepc = '/';
-	psepcN = '\\';
-	pseps[0] = '/';
-    }
-    else
-    {
-	psepc = '\\';
-	psepcN = '/';
-	pseps[0] = '\\';
-    }
-
-    // need to adjust the file name arguments and buffer names.
-    buflist_slash_adjust();
-    alist_slash_adjust();
-# ifdef FEAT_EVAL
-    scriptnames_slash_adjust();
-# endif
-    return NULL;
-}
-#endif
-
-/*
- * Process the updated 'wrap' option value.
- */
-    char *
-did_set_wrap(optset_T *args UNUSED)
-{
-    // If 'wrap' is set, set w_leftcol to zero.
-    if (curwin->w_p_wrap)
-	curwin->w_leftcol = 0;
-    return NULL;
-}
-
-/*
- * Process the updated 'equalalways' option value.
- */
-    char *
-did_set_equalalways(optset_T *args)
-{
-    if (p_ea && !args->os_oldval.boolean)
-	win_equal(curwin, FALSE, 0);
-
-    return NULL;
-}
-
-/*
- * Process the updated 'weirdinvert' option value.
- */
-    char *
-did_set_weirdinvert(optset_T *args)
-{
-    // When 'weirdinvert' changed, set/reset 't_xs'.
-    // Then set 'weirdinvert' according to value of 't_xs'.
-    if (p_wiv && !args->os_oldval.boolean)
-	T_XS = (char_u *)"y";
-    else if (!p_wiv && args->os_oldval.boolean)
-	T_XS = empty_option;
-    p_wiv = (*T_XS != NUL);
-
-    return NULL;
-}
-
-#if defined(FEAT_BEVAL_GUI) || defined(PROTO)
-/*
- * Process the updated 'ballooneval' option value.
- */
-    char *
-did_set_ballooneval(optset_T *args)
-{
-    if (balloonEvalForTerm)
-	return NULL;
-
-    if (p_beval && !args->os_oldval.boolean)
-	gui_mch_enable_beval_area(balloonEval);
-    else if (!p_beval && args->os_oldval.boolean)
-	gui_mch_disable_beval_area(balloonEval);
-
-    return NULL;
-}
-#endif
-
-#if defined(FEAT_BEVAL_TERM) || defined(PROTO)
-/*
- * Process the updated 'balloonevalterm' option value.
- */
-    char *
-did_set_balloonevalterm(optset_T *args UNUSED)
-{
-    mch_bevalterm_changed();
-    return NULL;
-}
-#endif
-
-#if defined(FEAT_AUTOCHDIR) || defined(PROTO)
-/*
- * Process the updated 'autochdir' option value.
- */
-    char *
-did_set_autochdir(optset_T *args UNUSED)
-{
-    // Change directories when the 'acd' option is set now.
-    DO_AUTOCHDIR;
-    return NULL;
-}
-#endif
-
-#if defined(FEAT_DIFF) || defined(PROTO)
-/*
- * Process the updated 'diff' option value.
- */
-    char *
-did_set_diff(optset_T *args UNUSED)
-{
-    // May add or remove the buffer from the list of diff buffers.
-    diff_buf_adjust(curwin);
-# ifdef FEAT_FOLDING
-    if (foldmethodIsDiff(curwin))
-	foldUpdateAll(curwin);
-# endif
-    return NULL;
-}
-#endif
-
-#if defined(HAVE_INPUT_METHOD) || defined(PROTO)
-/*
- * Process the updated 'imdisable' option value.
- */
-    char *
-did_set_imdisable(optset_T *args UNUSED)
-{
-    // Only de-activate it here, it will be enabled when changing mode.
-    if (p_imdisable)
-	im_set_active(FALSE);
-    else if (State & MODE_INSERT)
-	// When the option is set from an autocommand, it may need to take
-	// effect right away.
-	im_set_active(curbuf->b_p_iminsert == B_IMODE_IM);
-    return NULL;
-}
-#endif
-
-#if defined(FEAT_SPELL) || defined(PROTO)
-/*
- * Process the updated 'spell' option value.
- */
-    char *
-did_set_spell(optset_T *args UNUSED)
-{
-    if (curwin->w_p_spell)
-	return parse_spelllang(curwin);
-
-    return NULL;
-}
-#endif
-
 #if defined(FEAT_ARABIC) || defined(PROTO)
 /*
  * Process the updated 'arabic' option value.
@@ -3708,8 +3157,8 @@
 
 # ifdef FEAT_KEYMAP
 	// Force-set the necessary keymap for arabic
-	errmsg = set_option_value((char_u *)"keymap",
-		0L, (char_u *)"arabic", OPT_LOCAL);
+	errmsg = set_option_value((char_u *)"keymap", 0L, (char_u *)"arabic",
+								OPT_LOCAL);
 # endif
     }
     else
@@ -3742,6 +3191,511 @@
 }
 #endif
 
+#if defined(FEAT_AUTOCHDIR) || defined(PROTO)
+/*
+ * Process the updated 'autochdir' option value.
+ */
+    char *
+did_set_autochdir(optset_T *args UNUSED)
+{
+    // Change directories when the 'acd' option is set now.
+    DO_AUTOCHDIR;
+    return NULL;
+}
+#endif
+
+#if defined(FEAT_BEVAL_GUI) || defined(PROTO)
+/*
+ * Process the updated 'ballooneval' option value.
+ */
+    char *
+did_set_ballooneval(optset_T *args)
+{
+    if (balloonEvalForTerm)
+	return NULL;
+
+    if (p_beval && !args->os_oldval.boolean)
+	gui_mch_enable_beval_area(balloonEval);
+    else if (!p_beval && args->os_oldval.boolean)
+	gui_mch_disable_beval_area(balloonEval);
+
+    return NULL;
+}
+#endif
+
+#if defined(FEAT_BEVAL_TERM) || defined(PROTO)
+/*
+ * Process the updated 'balloonevalterm' option value.
+ */
+    char *
+did_set_balloonevalterm(optset_T *args UNUSED)
+{
+    mch_bevalterm_changed();
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'binary' option value.
+ */
+    char *
+did_set_binary(optset_T *args)
+{
+    // when 'bin' is set also set some other options
+    set_options_bin(args->os_oldval.boolean, curbuf->b_p_bin, args->os_flags);
+    redraw_titles();
+
+    return NULL;
+}
+
+#if defined(FEAT_LINEBREAK) || defined(PROTO)
+/*
+ * Called when the 'breakat' option changes value.
+ */
+    char *
+did_set_breakat(optset_T *args UNUSED)
+{
+    char_u	*p;
+    int		i;
+
+    for (i = 0; i < 256; i++)
+	breakat_flags[i] = FALSE;
+
+    if (p_breakat != NULL)
+	for (p = p_breakat; *p; p++)
+	    breakat_flags[*p] = TRUE;
+
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'buflisted' option value.
+ */
+    char *
+did_set_buflisted(optset_T *args)
+{
+    // when 'buflisted' changes, trigger autocommands
+    if (args->os_oldval.boolean != curbuf->b_p_bl)
+	apply_autocmds(curbuf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
+						NULL, NULL, TRUE, curbuf);
+    return NULL;
+}
+
+/*
+ * Process the new 'cmdheight' option value.
+ */
+    char *
+did_set_cmdheight(optset_T *args)
+{
+    long old_value = args->os_oldval.number;
+    char *errmsg = NULL;
+
+    // if p_ch changed value, change the command line height
+    if (p_ch < 1)
+    {
+	errmsg = e_argument_must_be_positive;
+	p_ch = 1;
+    }
+    if (p_ch > Rows - min_rows() + 1)
+	p_ch = Rows - min_rows() + 1;
+
+    // Only compute the new window layout when startup has been
+    // completed. Otherwise the frame sizes may be wrong.
+    if ((p_ch != old_value
+		|| tabline_height() + topframe->fr_height != Rows - p_ch)
+	    && full_screen
+#ifdef FEAT_GUI
+	    && !gui.starting
+#endif
+       )
+	command_height();
+
+    return errmsg;
+}
+
+/*
+ * Process the updated 'compatible' option value.
+ */
+    char *
+did_set_compatible(optset_T *args UNUSED)
+{
+    compatible_set();
+    return NULL;
+}
+
+#if defined(FEAT_CONCEAL) || defined(PROTO)
+/*
+ * Process the new 'conceallevel' option value.
+ */
+    char *
+did_set_conceallevel(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (curwin->w_p_cole < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	curwin->w_p_cole = 0;
+    }
+    else if (curwin->w_p_cole > 3)
+    {
+	errmsg = e_invalid_argument;
+	curwin->w_p_cole = 3;
+    }
+
+    return errmsg;
+}
+#endif
+
+#if defined(FEAT_DIFF) || defined(PROTO)
+/*
+ * Process the updated 'diff' option value.
+ */
+    char *
+did_set_diff(optset_T *args UNUSED)
+{
+    // May add or remove the buffer from the list of diff buffers.
+    diff_buf_adjust(curwin);
+# ifdef FEAT_FOLDING
+    if (foldmethodIsDiff(curwin))
+	foldUpdateAll(curwin);
+# endif
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'endoffile' or 'endofline' or 'fixendofline' or 'bomb'
+ * option value.
+ */
+    char *
+did_set_eof_eol_fixeol_bomb(optset_T *args UNUSED)
+{
+    // redraw the window title and tab page text
+    redraw_titles();
+    return NULL;
+}
+
+/*
+ * Process the updated 'equalalways' option value.
+ */
+    char *
+did_set_equalalways(optset_T *args)
+{
+    if (p_ea && !args->os_oldval.boolean)
+	win_equal(curwin, FALSE, 0);
+
+    return NULL;
+}
+
+#if defined(FEAT_FOLDING) || defined(PROTO)
+/*
+ * Process the new 'foldcolumn' option value.
+ */
+    char *
+did_set_foldcolumn(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (curwin->w_p_fdc < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	curwin->w_p_fdc = 0;
+    }
+    else if (curwin->w_p_fdc > 12)
+    {
+	errmsg = e_invalid_argument;
+	curwin->w_p_fdc = 12;
+    }
+
+    return errmsg;
+}
+
+/*
+ * Process the new 'foldlevel' option value.
+ */
+    char *
+did_set_foldlevel(optset_T *args UNUSED)
+{
+    if (curwin->w_p_fdl < 0)
+	curwin->w_p_fdl = 0;
+    newFoldLevel();
+    return NULL;
+}
+
+/*
+ * Process the new 'foldminlines' option value.
+ */
+    char *
+did_set_foldminlines(optset_T *args UNUSED)
+{
+    foldUpdateAll(curwin);
+    return NULL;
+}
+
+/*
+ * Process the new 'foldnestmax' option value.
+ */
+    char *
+did_set_foldnestmax(optset_T *args UNUSED)
+{
+    if (foldmethodIsSyntax(curwin) || foldmethodIsIndent(curwin))
+	foldUpdateAll(curwin);
+    return NULL;
+}
+#endif
+
+#if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
+/*
+ * Process the updated 'hlsearch' option value.
+ */
+    char *
+did_set_hlsearch(optset_T *args UNUSED)
+{
+    // when 'hlsearch' is set or reset: reset no_hlsearch
+    set_no_hlsearch(FALSE);
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'ignorecase' option value.
+ */
+    char *
+did_set_ignorecase(optset_T *args UNUSED)
+{
+    // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
+    if (p_hls)
+	redraw_all_later(UPD_SOME_VALID);
+    return NULL;
+}
+
+#if defined(HAVE_INPUT_METHOD) || defined(PROTO)
+/*
+ * Process the updated 'imdisable' option value.
+ */
+    char *
+did_set_imdisable(optset_T *args UNUSED)
+{
+    // Only de-activate it here, it will be enabled when changing mode.
+    if (p_imdisable)
+	im_set_active(FALSE);
+    else if (State & MODE_INSERT)
+	// When the option is set from an autocommand, it may need to take
+	// effect right away.
+	im_set_active(curbuf->b_p_iminsert == B_IMODE_IM);
+    return NULL;
+}
+#endif
+
+/*
+ * Process the new 'iminsert' option value.
+ */
+    char *
+did_set_iminsert(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (curbuf->b_p_iminsert < 0 || curbuf->b_p_iminsert > B_IMODE_LAST)
+    {
+	errmsg = e_invalid_argument;
+	curbuf->b_p_iminsert = B_IMODE_NONE;
+    }
+    p_iminsert = curbuf->b_p_iminsert;
+    if (termcap_active)	// don't do this in the alternate screen
+	showmode();
+#if defined(FEAT_KEYMAP)
+    // Show/unshow value of 'keymap' in status lines.
+    status_redraw_curbuf();
+#endif
+
+    return errmsg;
+}
+
+/*
+ * Process the new 'imsearch' option value.
+ */
+    char *
+did_set_imsearch(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (curbuf->b_p_imsearch < -1 || curbuf->b_p_imsearch > B_IMODE_LAST)
+    {
+	errmsg = e_invalid_argument;
+	curbuf->b_p_imsearch = B_IMODE_NONE;
+    }
+    p_imsearch = curbuf->b_p_imsearch;
+
+    return errmsg;
+}
+
+#if (defined(FEAT_XIM) && defined(FEAT_GUI_GTK)) || defined(PROTO)
+/*
+ * Process the new 'imstyle' option value.
+ */
+    char *
+did_set_imstyle(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (p_imst != IM_ON_THE_SPOT && p_imst != IM_OVER_THE_SPOT)
+	errmsg = e_invalid_argument;
+
+    return errmsg;
+}
+#endif
+
+/*
+ * Process the updated 'insertmode' option value.
+ */
+    char *
+did_set_insertmode(optset_T *args)
+{
+    // when 'insertmode' is set from an autocommand need to do work here
+    if (p_im)
+    {
+	if ((State & MODE_INSERT) == 0)
+	    need_start_insertmode = TRUE;
+	stop_insert_mode = FALSE;
+    }
+    // only reset if it was set previously
+    else if (args->os_oldval.boolean)
+    {
+	need_start_insertmode = FALSE;
+	stop_insert_mode = TRUE;
+	if (restart_edit != 0 && mode_displayed)
+	    clear_cmdline = TRUE;	// remove "(insert)"
+	restart_edit = 0;
+    }
+
+    return NULL;
+}
+
+#if defined(FEAT_LANGMAP) || defined(PROTO)
+/*
+ * Process the updated 'langnoremap' option value.
+ */
+    char *
+did_set_langnoremap(optset_T *args UNUSED)
+{
+    // 'langnoremap' -> !'langremap'
+    p_lrm = !p_lnr;
+    return NULL;
+}
+
+/*
+ * Process the updated 'langremap' option value.
+ */
+    char *
+did_set_langremap(optset_T *args UNUSED)
+{
+    // 'langremap' -> !'langnoremap'
+    p_lnr = !p_lrm;
+    return NULL;
+}
+#endif
+
+/*
+ * Process the new 'laststatus' option value.
+ */
+    char *
+did_set_laststatus(optset_T *args UNUSED)
+{
+    last_status(FALSE);	// (re)set last window status line
+    return NULL;
+}
+
+#if defined(FEAT_GUI) || defined(PROTO)
+/*
+ * Process the new 'linespace' option value.
+ */
+    char *
+did_set_linespace(optset_T *args UNUSED)
+{
+    // Recompute gui.char_height and resize the Vim window to keep the
+    // same number of lines.
+    if (gui.in_use && gui_mch_adjust_charheight() == OK)
+	gui_set_shellsize(FALSE, FALSE, RESIZE_VERT);
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'lisp' option value.
+ */
+    char *
+did_set_lisp(optset_T *args UNUSED)
+{
+    // When 'lisp' option changes include/exclude '-' in keyword characters.
+    (void)buf_init_chartab(curbuf, FALSE);	    // ignore errors
+    return NULL;
+}
+
+/*
+ * Process the new 'maxcombine' option value.
+ */
+    char *
+did_set_maxcombine(optset_T *args UNUSED)
+{
+    if (p_mco > MAX_MCO)
+	p_mco = MAX_MCO;
+    else if (p_mco < 0)
+	p_mco = 0;
+    screenclear();	    // will re-allocate the screen
+    return NULL;
+}
+
+/*
+ * Process the updated 'modifiable' option value.
+ */
+    char *
+did_set_modifiable(optset_T *args UNUSED)
+{
+    // when 'modifiable' is changed, redraw the window title
+
+# ifdef FEAT_TERMINAL
+    // Cannot set 'modifiable' when in Terminal mode.
+    if (curbuf->b_p_ma && (term_in_normal_mode() || (bt_terminal(curbuf)
+		    && curbuf->b_term != NULL && !term_is_finished(curbuf))))
+    {
+	curbuf->b_p_ma = FALSE;
+	args->os_doskip = TRUE;
+	return e_cannot_make_terminal_with_running_job_modifiable;
+    }
+# endif
+    redraw_titles();
+
+    return NULL;
+}
+
+/*
+ * Process the updated 'modified' option value.
+ */
+    char *
+did_set_modified(optset_T *args)
+{
+    if (!args->os_newval.boolean)
+	save_file_ff(curbuf);	// Buffer is unchanged
+    redraw_titles();
+    modified_was_set = args->os_newval.boolean;
+    return NULL;
+}
+
+#if defined(FEAT_GUI) || defined(PROTO)
+/*
+ * Process the updated 'mousehide' option value.
+ */
+    char *
+did_set_mousehide(optset_T *args UNUSED)
+{
+    if (!p_mh)
+	gui_mch_mousehide(FALSE);
+    return NULL;
+}
+#endif
+
 /*
  * Process the updated 'number' or 'relativenumber' option value.
  */
@@ -3766,7 +3720,381 @@
     return NULL;
 }
 
-#ifdef FEAT_TERMGUICOLORS
+#if defined(FEAT_LINEBREAK) || defined(PROTO)
+/*
+ * Process the new 'numberwidth' option value.
+ */
+    char *
+did_set_numberwidth(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    // 'numberwidth' must be positive
+    if (curwin->w_p_nuw < 1)
+    {
+	errmsg = e_argument_must_be_positive;
+	curwin->w_p_nuw = 1;
+    }
+    if (curwin->w_p_nuw > 20)
+    {
+	errmsg = e_invalid_argument;
+	curwin->w_p_nuw = 20;
+    }
+    curwin->w_nrwidth_line_count = 0; // trigger a redraw
+
+    return errmsg;
+}
+#endif
+
+/*
+ * Process the updated 'paste' option value.  Called after p_paste was set or
+ * reset.  When 'paste' is set or reset also change other options.
+ */
+    char *
+did_set_paste(optset_T *args UNUSED)
+{
+    static int	old_p_paste = FALSE;
+    static int	save_sm = 0;
+    static int	save_sta = 0;
+    static int	save_ru = 0;
+#ifdef FEAT_RIGHTLEFT
+    static int	save_ri = 0;
+    static int	save_hkmap = 0;
+#endif
+    buf_T	*buf;
+
+    if (p_paste)
+    {
+	// Paste switched from off to on.
+	// Save the current values, so they can be restored later.
+	if (!old_p_paste)
+	{
+	    // save options for each buffer
+	    FOR_ALL_BUFFERS(buf)
+	    {
+		buf->b_p_tw_nopaste = buf->b_p_tw;
+		buf->b_p_wm_nopaste = buf->b_p_wm;
+		buf->b_p_sts_nopaste = buf->b_p_sts;
+		buf->b_p_ai_nopaste = buf->b_p_ai;
+		buf->b_p_et_nopaste = buf->b_p_et;
+#ifdef FEAT_VARTABS
+		if (buf->b_p_vsts_nopaste)
+		    vim_free(buf->b_p_vsts_nopaste);
+		buf->b_p_vsts_nopaste =
+			buf->b_p_vsts && buf->b_p_vsts != empty_option
+					   ? vim_strsave(buf->b_p_vsts) : NULL;
+#endif
+	    }
+
+	    // save global options
+	    save_sm = p_sm;
+	    save_sta = p_sta;
+	    save_ru = p_ru;
+#ifdef FEAT_RIGHTLEFT
+	    save_ri = p_ri;
+	    save_hkmap = p_hkmap;
+#endif
+	    // save global values for local buffer options
+	    p_ai_nopaste = p_ai;
+	    p_et_nopaste = p_et;
+	    p_sts_nopaste = p_sts;
+	    p_tw_nopaste = p_tw;
+	    p_wm_nopaste = p_wm;
+#ifdef FEAT_VARTABS
+	    if (p_vsts_nopaste)
+		vim_free(p_vsts_nopaste);
+	    p_vsts_nopaste = p_vsts && p_vsts != empty_option
+						  ? vim_strsave(p_vsts) : NULL;
+#endif
+	}
+
+	// Always set the option values, also when 'paste' is set when it is
+	// already on.  Set options for each buffer.
+	FOR_ALL_BUFFERS(buf)
+	{
+	    buf->b_p_tw = 0;	    // textwidth is 0
+	    buf->b_p_wm = 0;	    // wrapmargin is 0
+	    buf->b_p_sts = 0;	    // softtabstop is 0
+	    buf->b_p_ai = 0;	    // no auto-indent
+	    buf->b_p_et = 0;	    // no expandtab
+#ifdef FEAT_VARTABS
+	    if (buf->b_p_vsts)
+		free_string_option(buf->b_p_vsts);
+	    buf->b_p_vsts = empty_option;
+	    VIM_CLEAR(buf->b_p_vsts_array);
+#endif
+	}
+
+	// set global options
+	p_sm = 0;		    // no showmatch
+	p_sta = 0;		    // no smarttab
+	if (p_ru)
+	    status_redraw_all();    // redraw to remove the ruler
+	p_ru = 0;		    // no ruler
+#ifdef FEAT_RIGHTLEFT
+	p_ri = 0;		    // no reverse insert
+	p_hkmap = 0;		    // no Hebrew keyboard
+#endif
+	// set global values for local buffer options
+	p_tw = 0;
+	p_wm = 0;
+	p_sts = 0;
+	p_ai = 0;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = empty_option;
+#endif
+    }
+
+    // Paste switched from on to off: Restore saved values.
+    else if (old_p_paste)
+    {
+	// restore options for each buffer
+	FOR_ALL_BUFFERS(buf)
+	{
+	    buf->b_p_tw = buf->b_p_tw_nopaste;
+	    buf->b_p_wm = buf->b_p_wm_nopaste;
+	    buf->b_p_sts = buf->b_p_sts_nopaste;
+	    buf->b_p_ai = buf->b_p_ai_nopaste;
+	    buf->b_p_et = buf->b_p_et_nopaste;
+#ifdef FEAT_VARTABS
+	    if (buf->b_p_vsts)
+		free_string_option(buf->b_p_vsts);
+	    buf->b_p_vsts = buf->b_p_vsts_nopaste
+			 ? vim_strsave(buf->b_p_vsts_nopaste) : empty_option;
+	    vim_free(buf->b_p_vsts_array);
+	    if (buf->b_p_vsts && buf->b_p_vsts != empty_option)
+		(void)tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_array);
+	    else
+		buf->b_p_vsts_array = NULL;
+#endif
+	}
+
+	// restore global options
+	p_sm = save_sm;
+	p_sta = save_sta;
+	if (p_ru != save_ru)
+	    status_redraw_all();    // redraw to draw the ruler
+	p_ru = save_ru;
+#ifdef FEAT_RIGHTLEFT
+	p_ri = save_ri;
+	p_hkmap = save_hkmap;
+#endif
+	// set global values for local buffer options
+	p_ai = p_ai_nopaste;
+	p_et = p_et_nopaste;
+	p_sts = p_sts_nopaste;
+	p_tw = p_tw_nopaste;
+	p_wm = p_wm_nopaste;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = p_vsts_nopaste ? vim_strsave(p_vsts_nopaste) : empty_option;
+#endif
+    }
+
+    old_p_paste = p_paste;
+
+    return NULL;
+}
+
+
+#ifdef FEAT_QUICKFIX
+/*
+ * Process the updated 'previewwindow' option value.
+ */
+    char *
+did_set_previewwindow(optset_T *args)
+{
+    if (!curwin->w_p_pvw)
+	return NULL;
+
+    // There can be only one window with 'previewwindow' set.
+    win_T	*win;
+
+    FOR_ALL_WINDOWS(win)
+	if (win->w_p_pvw && win != curwin)
+	{
+	    curwin->w_p_pvw = FALSE;
+	    args->os_doskip = TRUE;
+	    return e_preview_window_already_exists;
+	}
+
+    return NULL;
+}
+#endif
+
+#if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
+/*
+ * Process the new 'pyxversion' option value.
+ */
+    char *
+did_set_pyxversion(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (p_pyx != 0 && p_pyx != 2 && p_pyx != 3)
+	errmsg = e_invalid_argument;
+
+    return errmsg;
+}
+#endif
+
+/*
+ * Process the updated 'readonly' option value.
+ */
+    char *
+did_set_readonly(optset_T *args)
+{
+    // when 'readonly' is reset globally, also reset readonlymode
+    if (!curbuf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0)
+	readonlymode = FALSE;
+
+    // when 'readonly' is set may give W10 again
+    if (curbuf->b_p_ro)
+	curbuf->b_did_warn = FALSE;
+
+    redraw_titles();
+
+    return NULL;
+}
+
+/*
+ * Process the updated 'scrollbind' option value.
+ */
+    char *
+did_set_scrollbind(optset_T *args UNUSED)
+{
+    // when 'scrollbind' is set: snapshot the current position to avoid a jump
+    // at the end of normal_cmd()
+    if (!curwin->w_p_scb)
+	return NULL;
+
+    do_check_scrollbind(FALSE);
+    curwin->w_scbind_pos = curwin->w_topline;
+    return NULL;
+}
+
+#if defined(BACKSLASH_IN_FILENAME) || defined(PROTO)
+/*
+ * Process the updated 'shellslash' option value.
+ */
+    char *
+did_set_shellslash(optset_T *args UNUSED)
+{
+    if (p_ssl)
+    {
+	psepc = '/';
+	psepcN = '\\';
+	pseps[0] = '/';
+    }
+    else
+    {
+	psepc = '\\';
+	psepcN = '/';
+	pseps[0] = '\\';
+    }
+
+    // need to adjust the file name arguments and buffer names.
+    buflist_slash_adjust();
+    alist_slash_adjust();
+# ifdef FEAT_EVAL
+    scriptnames_slash_adjust();
+# endif
+    return NULL;
+}
+#endif
+
+/*
+ * Process the new 'shiftwidth' or the 'tabstop' option value.
+ */
+    char *
+did_set_shiftwidth_tabstop(optset_T *args)
+{
+    long	*pp = (long *)args->os_varp;
+    char	*errmsg = NULL;
+
+    if (curbuf->b_p_sw < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+#ifdef FEAT_VARTABS
+	// Use the first 'vartabstop' value, or 'tabstop' if vts isn't in use.
+	curbuf->b_p_sw = tabstop_count(curbuf->b_p_vts_array) > 0
+		       ? tabstop_first(curbuf->b_p_vts_array)
+		       : curbuf->b_p_ts;
+#else
+	curbuf->b_p_sw = curbuf->b_p_ts;
+#endif
+    }
+
+#ifdef FEAT_FOLDING
+    if (foldmethodIsIndent(curwin))
+	foldUpdateAll(curwin);
+#endif
+    // When 'shiftwidth' changes, or it's zero and 'tabstop' changes:
+    // parse 'cinoptions'.
+    if (pp == &curbuf->b_p_sw || curbuf->b_p_sw == 0)
+	parse_cino(curbuf);
+
+    return errmsg;
+}
+
+/*
+ * Process the new 'showtabline' option value.
+ */
+    char *
+did_set_showtabline(optset_T *args UNUSED)
+{
+    shell_new_rows();	// recompute window positions and heights
+    return NULL;
+}
+
+/*
+ * Process the updated 'smoothscroll' option value.
+ */
+    char *
+did_set_smoothscroll(optset_T *args UNUSED)
+{
+    if (curwin->w_p_sms)
+	return NULL;
+
+    curwin->w_skipcol = 0;
+    changed_line_abv_curs();
+    return NULL;
+}
+
+#if defined(FEAT_SPELL) || defined(PROTO)
+/*
+ * Process the updated 'spell' option value.
+ */
+    char *
+did_set_spell(optset_T *args UNUSED)
+{
+    if (curwin->w_p_spell)
+	return parse_spelllang(curwin);
+
+    return NULL;
+}
+#endif
+
+/*
+ * Process the updated 'swapfile' option value.
+ */
+    char *
+did_set_swapfile(optset_T *args UNUSED)
+{
+    // when 'swf' is set, create swapfile, when reset remove swapfile
+    if (curbuf->b_p_swf && p_uc)
+	ml_open_file(curbuf);		// create the swap file
+    else
+	// no need to reset curbuf->b_may_swap, ml_open_file() will check
+	// buf->b_p_swf
+	mf_close_file(curbuf, TRUE);	// remove the swap file
+    return NULL;
+}
+
+#if defined(FEAT_TERMGUICOLORS) || defined(PROTO)
     char *
 did_set_termguicolors(optset_T *args UNUSED)
 {
@@ -3809,92 +4137,250 @@
 #endif
 
 /*
- * Set the value of a boolean option, and take care of side effects.
- * Returns NULL for success, or an error message for an error.
+ * Process the updated 'terse' option value.
  */
-    static char *
-set_bool_option(
-    int		opt_idx,		// index in options[] table
-    char_u	*varp,			// pointer to the option variable
-    int		value,			// new value
-    int		opt_flags)		// OPT_LOCAL and/or OPT_GLOBAL
+    char *
+did_set_terse(optset_T *args UNUSED)
 {
-    int		old_value = *(int *)varp;
-#if defined(FEAT_EVAL)
-    int		old_global_value = 0;
-#endif
-    char	*errmsg = NULL;
+    char_u	*p;
 
-    // Disallow changing some options from secure mode
-    if ((secure
-#ifdef HAVE_SANDBOX
-		|| sandbox != 0
-#endif
-		) && (options[opt_idx].flags & P_SECURE))
-	return e_not_allowed_here;
+    // when 'terse' is set change 'shortmess'
+    p = vim_strchr(p_shm, SHM_SEARCH);
 
-#if defined(FEAT_EVAL)
-    // Save the global value before changing anything. This is needed as for
-    // a global-only option setting the "local value" in fact sets the global
-    // value (since there is only one value).
-    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
-	old_global_value = *(int *)get_varp_scope(&(options[opt_idx]),
-								   OPT_GLOBAL);
-#endif
-
-    *(int *)varp = value;	    // set the new value
-#ifdef FEAT_EVAL
-    // Remember where the option was set.
-    set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
-#endif
-
-#ifdef FEAT_GUI
-    need_mouse_correct = TRUE;
-#endif
-
-    // May set global value for local option.
-    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
-	*(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL) = value;
-
-    // Handle side effects of changing a bool option.
-    if (options[opt_idx].opt_did_set_cb != NULL)
+    // insert 's' in p_shm
+    if (p_terse && p == NULL)
     {
-	optset_T args;
-
-	args.os_varp = varp;
-	args.os_flags = opt_flags;
-	args.os_oldval.boolean = old_value;
-	args.os_newval.boolean = value;
-	args.os_doskip = FALSE;
-	args.os_errbuf = NULL;
-	errmsg = options[opt_idx].opt_did_set_cb(&args);
-	if (args.os_doskip)
-	    return errmsg;
+	STRCPY(IObuff, p_shm);
+	STRCAT(IObuff, "s");
+	set_string_option_direct((char_u *)"shm", -1, IObuff, OPT_FREE, 0);
     }
+    // remove 's' from p_shm
+    else if (!p_terse && p != NULL)
+	STRMOVE(p, p + 1);
+    return NULL;
+}
 
-    // after handling side effects, call autocommand
+/*
+ * Process the updated 'textauto' option value.
+ */
+    char *
+did_set_textauto(optset_T *args)
+{
+    // when 'textauto' is set or reset also change 'fileformats'
+    set_string_option_direct((char_u *)"ffs", -1,
+				p_ta ? (char_u *)DFLT_FFS_VIM : (char_u *)"",
+				OPT_FREE | args->os_flags, 0);
 
-    options[opt_idx].flags |= P_WAS_SET;
+    return NULL;
+}
 
-#if defined(FEAT_EVAL)
-    apply_optionset_autocmd(opt_idx, opt_flags,
-				(long)(old_value ? TRUE : FALSE),
-				(long)(old_global_value ? TRUE : FALSE),
-				(long)(value ? TRUE : FALSE), NULL);
+/*
+ * Process the updated 'textmode' option value.
+ */
+    char *
+did_set_textmode(optset_T *args)
+{
+    // when 'textmode' is set or reset also change 'fileformat'
+    set_fileformat(curbuf->b_p_tx ? EOL_DOS : EOL_UNIX, args->os_flags);
+
+    return NULL;
+}
+
+/*
+ * Process the new 'textwidth' option value.
+ */
+    char *
+did_set_textwidth(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (curbuf->b_p_tw < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	curbuf->b_p_tw = 0;
+    }
+#ifdef FEAT_SYN_HL
+    {
+	win_T	*wp;
+	tabpage_T	*tp;
+
+	FOR_ALL_TAB_WINDOWS(tp, wp)
+	    check_colorcolumn(wp);
+    }
 #endif
 
-    comp_col();			    // in case 'ruler' or 'showcmd' changed
-    if (curwin->w_curswant != MAXCOL
-		     && (options[opt_idx].flags & (P_CURSWANT | P_RALL)) != 0)
-	curwin->w_set_curswant = TRUE;
-
-    if ((opt_flags & OPT_NO_REDRAW) == 0)
-	check_redraw(options[opt_idx].flags);
-
     return errmsg;
 }
 
 /*
+ * Process the updated 'title' or the 'icon' option value.
+ */
+    char *
+did_set_title_icon(optset_T *args UNUSED)
+{
+    // when 'title' changed, may need to change the title; same for 'icon'
+    did_set_title();
+    return NULL;
+}
+
+/*
+ * Process the new 'titlelen' option value.
+ */
+    char *
+did_set_titlelen(optset_T *args)
+{
+    long old_value = args->os_oldval.number;
+    char *errmsg = NULL;
+
+    // if 'titlelen' has changed, redraw the title
+    if (p_titlelen < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	p_titlelen = 85;
+    }
+    if (starting != NO_SCREEN && old_value != p_titlelen)
+	need_maketitle = TRUE;
+
+    return errmsg;
+}
+
+#if defined(FEAT_PERSISTENT_UNDO) || defined(PROTO)
+/*
+ * Process the updated 'undofile' option value.
+ */
+    char *
+did_set_undofile(optset_T *args)
+{
+    // Only take action when the option was set.
+    if (!curbuf->b_p_udf && !p_udf)
+	return NULL;
+
+    // When reset we do not delete the undo file, the option may be set again
+    // without making any changes in between.
+    char_u	hash[UNDO_HASH_SIZE];
+    buf_T	*save_curbuf = curbuf;
+
+    FOR_ALL_BUFFERS(curbuf)
+    {
+	// When 'undofile' is set globally: for every buffer, otherwise
+	// only for the current buffer: Try to read in the undofile,
+	// if one exists, the buffer wasn't changed and the buffer was
+	// loaded
+	if ((curbuf == save_curbuf
+		    || (args->os_flags & OPT_GLOBAL)
+		    || args->os_flags == 0)
+		&& !curbufIsChanged() && curbuf->b_ml.ml_mfp != NULL)
+	{
+#ifdef FEAT_CRYPT
+	    if (crypt_get_method_nr(curbuf) == CRYPT_M_SOD)
+		continue;
+#endif
+	    u_compute_hash(hash);
+	    u_read_undo(NULL, hash, curbuf->b_fname);
+	}
+    }
+    curbuf = save_curbuf;
+
+    return NULL;
+}
+#endif
+
+/*
+ * Process the new global 'undolevels' option value.
+ */
+    static void
+update_global_undolevels(long value, long old_value)
+{
+    // sync undo before 'undolevels' changes
+
+    // use the old value, otherwise u_sync() may not work properly
+    p_ul = old_value;
+    u_sync(TRUE);
+    p_ul = value;
+}
+
+/*
+ * Process the new buffer local 'undolevels' option value.
+ */
+    static void
+update_buflocal_undolevels(long value, long old_value)
+{
+    // use the old value, otherwise u_sync() may not work properly
+    curbuf->b_p_ul = old_value;
+    u_sync(TRUE);
+    curbuf->b_p_ul = value;
+}
+
+/*
+ * Process the new 'undolevels' option value.
+ */
+    char *
+did_set_undolevels(optset_T *args)
+{
+    long *pp = (long *)args->os_varp;
+
+    if (pp == &p_ul)			// global 'undolevels'
+	update_global_undolevels(args->os_newval.number,
+						       args->os_oldval.number);
+    else if (pp == &curbuf->b_p_ul)	// buffer local 'undolevels'
+	update_buflocal_undolevels(args->os_newval.number,
+						       args->os_oldval.number);
+
+    return NULL;
+}
+
+/*
+ * Process the new 'updatecount' option value.
+ */
+    char *
+did_set_updatecount(optset_T *args)
+{
+    long old_value = args->os_oldval.number;
+    char *errmsg = NULL;
+
+    // when 'updatecount' changes from zero to non-zero, open swap files
+    if (p_uc < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	p_uc = 100;
+    }
+    if (p_uc && !old_value)
+	ml_open_files();
+
+    return errmsg;
+}
+
+/*
+ * Process the updated 'weirdinvert' option value.
+ */
+    char *
+did_set_weirdinvert(optset_T *args)
+{
+    // When 'weirdinvert' changed, set/reset 't_xs'.
+    // Then set 'weirdinvert' according to value of 't_xs'.
+    if (p_wiv && !args->os_oldval.boolean)
+	T_XS = (char_u *)"y";
+    else if (!p_wiv && args->os_oldval.boolean)
+	T_XS = empty_option;
+    p_wiv = (*T_XS != NUL);
+
+    return NULL;
+}
+
+/*
+ * Process the new 'window' option value.
+ */
+    char *
+did_set_window(optset_T *args UNUSED)
+{
+    if (p_window < 1)
+	p_window = 1;
+    else if (p_window >= Rows)
+	p_window = Rows - 1;
+    return NULL;
+}
+
+/*
  * Process the new 'winheight' or the 'helpheight' option value.
  */
     char *
@@ -3955,6 +4441,29 @@
 }
 
 /*
+ * Process the new 'winminwidth' option value.
+ */
+    char *
+did_set_winminwidth(optset_T *args UNUSED)
+{
+    char *errmsg = NULL;
+
+    if (p_wmw < 0)
+    {
+	errmsg = e_argument_must_be_positive;
+	p_wmw = 0;
+    }
+    if (p_wmw > p_wiw)
+    {
+	errmsg = e_winwidth_cannot_be_smaller_than_winminwidth;
+	p_wmw = p_wiw;
+    }
+    win_setminwidth();
+
+    return errmsg;
+}
+
+/*
  * Process the new 'winwidth' option value.
  */
     char *
@@ -3981,448 +4490,102 @@
 }
 
 /*
- * Process the new 'winminwidth' option value.
+ * Process the updated 'wrap' option value.
  */
     char *
-did_set_winminwidth(optset_T *args UNUSED)
+did_set_wrap(optset_T *args UNUSED)
 {
-    char *errmsg = NULL;
-
-    if (p_wmw < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	p_wmw = 0;
-    }
-    if (p_wmw > p_wiw)
-    {
-	errmsg = e_winwidth_cannot_be_smaller_than_winminwidth;
-	p_wmw = p_wiw;
-    }
-    win_setminwidth();
-
-    return errmsg;
-}
-
-/*
- * Process the new 'laststatus' option value.
- */
-    char *
-did_set_laststatus(optset_T *args UNUSED)
-{
-    last_status(FALSE);	// (re)set last window status line
+    // If 'wrap' is set, set w_leftcol to zero.
+    if (curwin->w_p_wrap)
+	curwin->w_leftcol = 0;
     return NULL;
 }
 
 /*
- * Process the new 'showtabline' option value.
+ * Set the value of a boolean option, and take care of side effects.
+ * Returns NULL for success, or an error message for an error.
  */
-    char *
-did_set_showtabline(optset_T *args UNUSED)
+    static char *
+set_bool_option(
+    int		opt_idx,		// index in options[] table
+    char_u	*varp,			// pointer to the option variable
+    int		value,			// new value
+    int		opt_flags)		// OPT_LOCAL and/or OPT_GLOBAL
 {
-    shell_new_rows();	// recompute window positions and heights
-    return NULL;
-}
-
-#if defined(FEAT_GUI) || defined(PROTO)
-/*
- * Process the new 'linespace' option value.
- */
-    char *
-did_set_linespace(optset_T *args UNUSED)
-{
-    // Recompute gui.char_height and resize the Vim window to keep the
-    // same number of lines.
-    if (gui.in_use && gui_mch_adjust_charheight() == OK)
-	gui_set_shellsize(FALSE, FALSE, RESIZE_VERT);
-    return NULL;
-}
+    int		old_value = *(int *)varp;
+#if defined(FEAT_EVAL)
+    int		old_global_value = 0;
 #endif
-
-#if defined(FEAT_FOLDING) || defined(PROTO)
-/*
- * Process the new 'foldlevel' option value.
- */
-    char *
-did_set_foldlevel(optset_T *args UNUSED)
-{
-    if (curwin->w_p_fdl < 0)
-	curwin->w_p_fdl = 0;
-    newFoldLevel();
-    return NULL;
-}
-
-/*
- * Process the new 'foldminlines' option value.
- */
-    char *
-did_set_foldminlines(optset_T *args UNUSED)
-{
-    foldUpdateAll(curwin);
-    return NULL;
-}
-
-/*
- * Process the new 'foldnestmax' option value.
- */
-    char *
-did_set_foldnestmax(optset_T *args UNUSED)
-{
-    if (foldmethodIsSyntax(curwin) || foldmethodIsIndent(curwin))
-	foldUpdateAll(curwin);
-    return NULL;
-}
-
-/*
- * Process the new 'foldcolumn' option value.
- */
-    char *
-did_set_foldcolumn(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (curwin->w_p_fdc < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	curwin->w_p_fdc = 0;
-    }
-    else if (curwin->w_p_fdc > 12)
-    {
-	errmsg = e_invalid_argument;
-	curwin->w_p_fdc = 12;
-    }
-
-    return errmsg;
-}
-#endif
-
-/*
- * Process the new 'shiftwidth' or the 'tabstop' option value.
- */
-    char *
-did_set_shiftwidth_tabstop(optset_T *args)
-{
-    long	*pp = (long *)args->os_varp;
     char	*errmsg = NULL;
 
-    if (curbuf->b_p_sw < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-#ifdef FEAT_VARTABS
-	// Use the first 'vartabstop' value, or 'tabstop' if vts isn't in use.
-	curbuf->b_p_sw = tabstop_count(curbuf->b_p_vts_array) > 0
-		       ? tabstop_first(curbuf->b_p_vts_array)
-		       : curbuf->b_p_ts;
-#else
-	curbuf->b_p_sw = curbuf->b_p_ts;
+    // Disallow changing some options from secure mode
+    if ((secure
+#ifdef HAVE_SANDBOX
+		|| sandbox != 0
 #endif
-    }
+		) && (options[opt_idx].flags & P_SECURE))
+	return e_not_allowed_here;
 
-#ifdef FEAT_FOLDING
-    if (foldmethodIsIndent(curwin))
-	foldUpdateAll(curwin);
-#endif
-    // When 'shiftwidth' changes, or it's zero and 'tabstop' changes:
-    // parse 'cinoptions'.
-    if (pp == &curbuf->b_p_sw || curbuf->b_p_sw == 0)
-	parse_cino(curbuf);
-
-    return errmsg;
-}
-
-/*
- * Process the new 'maxcombine' option value.
- */
-    char *
-did_set_maxcombine(optset_T *args UNUSED)
-{
-    if (p_mco > MAX_MCO)
-	p_mco = MAX_MCO;
-    else if (p_mco < 0)
-	p_mco = 0;
-    screenclear();	    // will re-allocate the screen
-    return NULL;
-}
-
-/*
- * Process the new 'iminsert' option value.
- */
-    char *
-did_set_iminsert(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (curbuf->b_p_iminsert < 0 || curbuf->b_p_iminsert > B_IMODE_LAST)
-    {
-	errmsg = e_invalid_argument;
-	curbuf->b_p_iminsert = B_IMODE_NONE;
-    }
-    p_iminsert = curbuf->b_p_iminsert;
-    if (termcap_active)	// don't do this in the alternate screen
-	showmode();
-#if defined(FEAT_KEYMAP)
-    // Show/unshow value of 'keymap' in status lines.
-    status_redraw_curbuf();
+#if defined(FEAT_EVAL)
+    // Save the global value before changing anything. This is needed as for
+    // a global-only option setting the "local value" in fact sets the global
+    // value (since there is only one value).
+    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
+	old_global_value = *(int *)get_varp_scope(&(options[opt_idx]),
+								   OPT_GLOBAL);
 #endif
 
-    return errmsg;
-}
-
-#if (defined(FEAT_XIM) && defined(FEAT_GUI_GTK)) || defined(PROTO)
-/*
- * Process the new 'imstyle' option value.
- */
-    char *
-did_set_imstyle(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (p_imst != IM_ON_THE_SPOT && p_imst != IM_OVER_THE_SPOT)
-	errmsg = e_invalid_argument;
-
-    return errmsg;
-}
+    *(int *)varp = value;	    // set the new value
+#ifdef FEAT_EVAL
+    // Remember where the option was set.
+    set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
 #endif
 
-/*
- * Process the new 'window' option value.
- */
-    char *
-did_set_window(optset_T *args UNUSED)
-{
-    if (p_window < 1)
-	p_window = 1;
-    else if (p_window >= Rows)
-	p_window = Rows - 1;
-    return NULL;
-}
-
-/*
- * Process the new 'imsearch' option value.
- */
-    char *
-did_set_imsearch(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (curbuf->b_p_imsearch < -1 || curbuf->b_p_imsearch > B_IMODE_LAST)
-    {
-	errmsg = e_invalid_argument;
-	curbuf->b_p_imsearch = B_IMODE_NONE;
-    }
-    p_imsearch = curbuf->b_p_imsearch;
-
-    return errmsg;
-}
-
-/*
- * Process the new 'titlelen' option value.
- */
-    char *
-did_set_titlelen(optset_T *args)
-{
-    long old_value = args->os_oldval.number;
-    char *errmsg = NULL;
-
-    // if 'titlelen' has changed, redraw the title
-    if (p_titlelen < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	p_titlelen = 85;
-    }
-    if (starting != NO_SCREEN && old_value != p_titlelen)
-	need_maketitle = TRUE;
-
-    return errmsg;
-}
-
-/*
- * Process the new 'cmdheight' option value.
- */
-    char *
-did_set_cmdheight(optset_T *args)
-{
-    long old_value = args->os_oldval.number;
-    char *errmsg = NULL;
-
-    // if p_ch changed value, change the command line height
-    if (p_ch < 1)
-    {
-	errmsg = e_argument_must_be_positive;
-	p_ch = 1;
-    }
-    if (p_ch > Rows - min_rows() + 1)
-	p_ch = Rows - min_rows() + 1;
-
-    // Only compute the new window layout when startup has been
-    // completed. Otherwise the frame sizes may be wrong.
-    if ((p_ch != old_value
-		|| tabline_height() + topframe->fr_height != Rows - p_ch)
-	    && full_screen
 #ifdef FEAT_GUI
-	    && !gui.starting
-#endif
-       )
-	command_height();
-
-    return errmsg;
-}
-
-/*
- * Process the new 'updatecount' option value.
- */
-    char *
-did_set_updatecount(optset_T *args)
-{
-    long old_value = args->os_oldval.number;
-    char *errmsg = NULL;
-
-    // when 'updatecount' changes from zero to non-zero, open swap files
-    if (p_uc < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	p_uc = 100;
-    }
-    if (p_uc && !old_value)
-	ml_open_files();
-
-    return errmsg;
-}
-
-#if defined(FEAT_CONCEAL) || defined(PROTO)
-/*
- * Process the new 'conceallevel' option value.
- */
-    char *
-did_set_conceallevel(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (curwin->w_p_cole < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	curwin->w_p_cole = 0;
-    }
-    else if (curwin->w_p_cole > 3)
-    {
-	errmsg = e_invalid_argument;
-	curwin->w_p_cole = 3;
-    }
-
-    return errmsg;
-}
+    need_mouse_correct = TRUE;
 #endif
 
-#if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
-/*
- * Process the new 'pyxversion' option value.
- */
-    char *
-did_set_pyxversion(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
+    // May set global value for local option.
+    if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
+	*(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL) = value;
 
-    if (p_pyx != 0 && p_pyx != 2 && p_pyx != 3)
-	errmsg = e_invalid_argument;
+    // Handle side effects of changing a bool option.
+    if (options[opt_idx].opt_did_set_cb != NULL)
+    {
+	optset_T args;
 
-    return errmsg;
-}
+	CLEAR_FIELD(args);
+	args.os_varp = varp;
+	args.os_flags = opt_flags;
+	args.os_oldval.boolean = old_value;
+	args.os_newval.boolean = value;
+	args.os_errbuf = NULL;
+	errmsg = options[opt_idx].opt_did_set_cb(&args);
+	if (args.os_doskip)
+	    return errmsg;
+    }
+
+    // after handling side effects, call autocommand
+
+    options[opt_idx].flags |= P_WAS_SET;
+
+#if defined(FEAT_EVAL)
+    apply_optionset_autocmd(opt_idx, opt_flags,
+				(long)(old_value ? TRUE : FALSE),
+				(long)(old_global_value ? TRUE : FALSE),
+				(long)(value ? TRUE : FALSE), NULL);
 #endif
 
-/*
- * Process the new global 'undolevels' option value.
- */
-    static void
-did_set_global_undolevels(long value, long old_value)
-{
-    // sync undo before 'undolevels' changes
+    comp_col();			    // in case 'ruler' or 'showcmd' changed
+    if (curwin->w_curswant != MAXCOL
+		     && (options[opt_idx].flags & (P_CURSWANT | P_RALL)) != 0)
+	curwin->w_set_curswant = TRUE;
 
-    // use the old value, otherwise u_sync() may not work properly
-    p_ul = old_value;
-    u_sync(TRUE);
-    p_ul = value;
-}
-
-/*
- * Process the new buffer local 'undolevels' option value.
- */
-    static void
-did_set_buflocal_undolevels(long value, long old_value)
-{
-    // use the old value, otherwise u_sync() may not work properly
-    curbuf->b_p_ul = old_value;
-    u_sync(TRUE);
-    curbuf->b_p_ul = value;
-}
-
-#if defined(FEAT_LINEBREAK) || defined(PROTO)
-/*
- * Process the new 'numberwidth' option value.
- */
-    char *
-did_set_numberwidth(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    // 'numberwidth' must be positive
-    if (curwin->w_p_nuw < 1)
-    {
-	errmsg = e_argument_must_be_positive;
-	curwin->w_p_nuw = 1;
-    }
-    if (curwin->w_p_nuw > 20)
-    {
-	errmsg = e_invalid_argument;
-	curwin->w_p_nuw = 20;
-    }
-    curwin->w_nrwidth_line_count = 0; // trigger a redraw
+    if ((opt_flags & OPT_NO_REDRAW) == 0)
+	check_redraw(options[opt_idx].flags);
 
     return errmsg;
 }
-#endif
-
-/*
- * Process the new 'textwidth' option value.
- */
-    char *
-did_set_textwidth(optset_T *args UNUSED)
-{
-    char *errmsg = NULL;
-
-    if (curbuf->b_p_tw < 0)
-    {
-	errmsg = e_argument_must_be_positive;
-	curbuf->b_p_tw = 0;
-    }
-#ifdef FEAT_SYN_HL
-    {
-	win_T	*wp;
-	tabpage_T	*tp;
-
-	FOR_ALL_TAB_WINDOWS(tp, wp)
-	    check_colorcolumn(wp);
-    }
-#endif
-
-    return errmsg;
-}
-
-/*
- * Process the new 'undolevels' option value.
- */
-    char *
-did_set_undolevels(optset_T *args)
-{
-    long *pp = (long *)args->os_varp;
-
-    if (pp == &p_ul)			// global 'undolevels'
-	did_set_global_undolevels(args->os_newval.number,
-						       args->os_oldval.number);
-    else if (pp == &curbuf->b_p_ul)	// buffer local 'undolevels'
-	did_set_buflocal_undolevels(args->os_newval.number,
-						       args->os_oldval.number);
-
-    return NULL;
-}
 
 /*
  * Check the bounds of numeric options.
@@ -4632,6 +4795,7 @@
     {
 	optset_T args;
 
+	CLEAR_FIELD(args);
 	args.os_varp = varp;
 	args.os_flags = opt_flags;
 	args.os_oldval.number = old_value;
@@ -7656,156 +7820,6 @@
 }
 
 /*
- * paste_option_changed() - Called after p_paste was set or reset.
- */
-    static void
-paste_option_changed(void)
-{
-    static int	old_p_paste = FALSE;
-    static int	save_sm = 0;
-    static int	save_sta = 0;
-    static int	save_ru = 0;
-#ifdef FEAT_RIGHTLEFT
-    static int	save_ri = 0;
-    static int	save_hkmap = 0;
-#endif
-    buf_T	*buf;
-
-    if (p_paste)
-    {
-	// Paste switched from off to on.
-	// Save the current values, so they can be restored later.
-	if (!old_p_paste)
-	{
-	    // save options for each buffer
-	    FOR_ALL_BUFFERS(buf)
-	    {
-		buf->b_p_tw_nopaste = buf->b_p_tw;
-		buf->b_p_wm_nopaste = buf->b_p_wm;
-		buf->b_p_sts_nopaste = buf->b_p_sts;
-		buf->b_p_ai_nopaste = buf->b_p_ai;
-		buf->b_p_et_nopaste = buf->b_p_et;
-#ifdef FEAT_VARTABS
-		if (buf->b_p_vsts_nopaste)
-		    vim_free(buf->b_p_vsts_nopaste);
-		buf->b_p_vsts_nopaste =
-			buf->b_p_vsts && buf->b_p_vsts != empty_option
-					   ? vim_strsave(buf->b_p_vsts) : NULL;
-#endif
-	    }
-
-	    // save global options
-	    save_sm = p_sm;
-	    save_sta = p_sta;
-	    save_ru = p_ru;
-#ifdef FEAT_RIGHTLEFT
-	    save_ri = p_ri;
-	    save_hkmap = p_hkmap;
-#endif
-	    // save global values for local buffer options
-	    p_ai_nopaste = p_ai;
-	    p_et_nopaste = p_et;
-	    p_sts_nopaste = p_sts;
-	    p_tw_nopaste = p_tw;
-	    p_wm_nopaste = p_wm;
-#ifdef FEAT_VARTABS
-	    if (p_vsts_nopaste)
-		vim_free(p_vsts_nopaste);
-	    p_vsts_nopaste = p_vsts && p_vsts != empty_option
-						  ? vim_strsave(p_vsts) : NULL;
-#endif
-	}
-
-	// Always set the option values, also when 'paste' is set when it is
-	// already on.  Set options for each buffer.
-	FOR_ALL_BUFFERS(buf)
-	{
-	    buf->b_p_tw = 0;	    // textwidth is 0
-	    buf->b_p_wm = 0;	    // wrapmargin is 0
-	    buf->b_p_sts = 0;	    // softtabstop is 0
-	    buf->b_p_ai = 0;	    // no auto-indent
-	    buf->b_p_et = 0;	    // no expandtab
-#ifdef FEAT_VARTABS
-	    if (buf->b_p_vsts)
-		free_string_option(buf->b_p_vsts);
-	    buf->b_p_vsts = empty_option;
-	    VIM_CLEAR(buf->b_p_vsts_array);
-#endif
-	}
-
-	// set global options
-	p_sm = 0;		    // no showmatch
-	p_sta = 0;		    // no smarttab
-	if (p_ru)
-	    status_redraw_all();    // redraw to remove the ruler
-	p_ru = 0;		    // no ruler
-#ifdef FEAT_RIGHTLEFT
-	p_ri = 0;		    // no reverse insert
-	p_hkmap = 0;		    // no Hebrew keyboard
-#endif
-	// set global values for local buffer options
-	p_tw = 0;
-	p_wm = 0;
-	p_sts = 0;
-	p_ai = 0;
-#ifdef FEAT_VARTABS
-	if (p_vsts)
-	    free_string_option(p_vsts);
-	p_vsts = empty_option;
-#endif
-    }
-
-    // Paste switched from on to off: Restore saved values.
-    else if (old_p_paste)
-    {
-	// restore options for each buffer
-	FOR_ALL_BUFFERS(buf)
-	{
-	    buf->b_p_tw = buf->b_p_tw_nopaste;
-	    buf->b_p_wm = buf->b_p_wm_nopaste;
-	    buf->b_p_sts = buf->b_p_sts_nopaste;
-	    buf->b_p_ai = buf->b_p_ai_nopaste;
-	    buf->b_p_et = buf->b_p_et_nopaste;
-#ifdef FEAT_VARTABS
-	    if (buf->b_p_vsts)
-		free_string_option(buf->b_p_vsts);
-	    buf->b_p_vsts = buf->b_p_vsts_nopaste
-			 ? vim_strsave(buf->b_p_vsts_nopaste) : empty_option;
-	    vim_free(buf->b_p_vsts_array);
-	    if (buf->b_p_vsts && buf->b_p_vsts != empty_option)
-		(void)tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_array);
-	    else
-		buf->b_p_vsts_array = NULL;
-#endif
-	}
-
-	// restore global options
-	p_sm = save_sm;
-	p_sta = save_sta;
-	if (p_ru != save_ru)
-	    status_redraw_all();    // redraw to draw the ruler
-	p_ru = save_ru;
-#ifdef FEAT_RIGHTLEFT
-	p_ri = save_ri;
-	p_hkmap = save_hkmap;
-#endif
-	// set global values for local buffer options
-	p_ai = p_ai_nopaste;
-	p_et = p_et_nopaste;
-	p_sts = p_sts_nopaste;
-	p_tw = p_tw_nopaste;
-	p_wm = p_wm_nopaste;
-#ifdef FEAT_VARTABS
-	if (p_vsts)
-	    free_string_option(p_vsts);
-	p_vsts = p_vsts_nopaste ? vim_strsave(p_vsts_nopaste) : empty_option;
-#endif
-    }
-
-    old_p_paste = p_paste;
-}
-
-/*
  * vimrc_found() - Called when a ".vimrc" or "VIMINIT" has been found.
  *
  * Reset 'compatible' and set the values for options that didn't get set yet
@@ -7919,28 +7933,6 @@
     didset_options2();
 }
 
-#if defined(FEAT_LINEBREAK) || defined(PROTO)
-
-/*
- * Called when the 'breakat' option changes value.
- */
-    char *
-did_set_breakat(optset_T *args UNUSED)
-{
-    char_u	*p;
-    int		i;
-
-    for (i = 0; i < 256; i++)
-	breakat_flags[i] = FALSE;
-
-    if (p_breakat != NULL)
-	for (p = p_breakat; *p; p++)
-	    breakat_flags[*p] = TRUE;
-
-    return NULL;
-}
-#endif
-
 /*
  * Check if backspacing over something is allowed.
  */
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 668e62f..5bd82fc 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -2506,7 +2506,7 @@
 #endif
 			    SCTX_INIT},
     {"term",	    NULL,   P_STRING|P_EXPAND|P_NODEFAULT|P_NO_MKRC|P_VI_DEF|P_RALL,
-			    (char_u *)&T_NAME, PV_NONE, NULL,
+			    (char_u *)&T_NAME, PV_NONE, did_set_term,
 			    {(char_u *)"", (char_u *)0L} SCTX_INIT},
     {"termbidi", "tbidi",   P_BOOL|P_VI_DEF,
 #ifdef FEAT_ARABIC
@@ -2662,7 +2662,7 @@
 			    (char_u *)&p_ttyscroll, PV_NONE, NULL,
 			    {(char_u *)999L, (char_u *)0L} SCTX_INIT},
     {"ttytype",	    "tty",  P_STRING|P_EXPAND|P_NODEFAULT|P_NO_MKRC|P_VI_DEF|P_RALL,
-			    (char_u *)&T_NAME, PV_NONE, NULL,
+			    (char_u *)&T_NAME, PV_NONE, did_set_term,
 			    {(char_u *)"", (char_u *)0L} SCTX_INIT},
     {"undodir",     "udir", P_STRING|P_EXPAND|P_ONECOMMA|P_NODUP|P_SECURE
 								    |P_VI_DEF,
diff --git a/src/optionstr.c b/src/optionstr.c
index aff8b61..0389ed0 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -2247,8 +2247,7 @@
     char *
 did_set_selection(optset_T *args UNUSED)
 {
-    if (*p_sel == NUL
-	    || check_opt_strings(p_sel, p_sel_values, FALSE) != OK)
+    if (*p_sel == NUL || check_opt_strings(p_sel, p_sel_values, FALSE) != OK)
 	return e_invalid_argument;
 
     return NULL;
@@ -2398,7 +2397,7 @@
 {
     char_u	**varp = (char_u **)args->os_varp;
 
-    if (**varp != NUL && STRCMP("camel", *varp) != 0)
+    if (**varp != NUL && STRCMP(*varp, "camel") != 0)
 	return e_invalid_argument;
 
     return NULL;
@@ -2499,34 +2498,24 @@
 /*
  * The 'term' option is changed.
  */
-    static char *
-did_set_term(int *opt_idx, long_u *free_oldval)
+    char *
+did_set_term(optset_T *args UNUSED)
 {
-    char *errmsg = NULL;
-
     if (T_NAME[0] == NUL)
-	errmsg = e_cannot_set_term_to_empty_string;
+	return e_cannot_set_term_to_empty_string;
 #ifdef FEAT_GUI
-    else if (gui.in_use)
-	errmsg = e_cannot_change_term_in_GUI;
-    else if (term_is_gui(T_NAME))
-	errmsg = e_use_gui_to_start_GUI;
+    if (gui.in_use)
+	return e_cannot_change_term_in_GUI;
+    if (term_is_gui(T_NAME))
+	return e_use_gui_to_start_GUI;
 #endif
-    else if (set_termname(T_NAME) == FAIL)
-	errmsg = e_not_found_in_termcap;
-    else
-    {
-	// Screen colors may have changed.
-	redraw_later_clear();
+    if (set_termname(T_NAME) == FAIL)
+	return e_not_found_in_termcap;
 
-	// Both 'term' and 'ttytype' point to T_NAME, only set the
-	// P_ALLOCED flag on 'term'.
-	*opt_idx = findoption((char_u *)"term");
-	if (*opt_idx >= 0)
-	    *free_oldval = (get_option_flags(*opt_idx) & P_ALLOCED);
-    }
+    // Screen colors may have changed.
+    redraw_later_clear();
 
-    return errmsg;
+    return NULL;
 }
 
 /*
@@ -2604,8 +2593,7 @@
     char *
 did_set_termwinkey(optset_T *args UNUSED)
 {
-    if (*curwin->w_p_twk != NUL
-	    && string_to_key(curwin->w_p_twk, TRUE) == 0)
+    if (*curwin->w_p_twk != NUL && string_to_key(curwin->w_p_twk, TRUE) == 0)
 	return e_invalid_argument;
 
     return NULL;
@@ -2664,8 +2652,8 @@
     char *
 did_set_toolbar(optset_T *args UNUSED)
 {
-    if (opt_strings_flags(p_toolbar, p_toolbar_values,
-		&toolbar_flags, TRUE) != OK)
+    if (opt_strings_flags(p_toolbar, p_toolbar_values, &toolbar_flags,
+								TRUE) != OK)
 	return e_invalid_argument;
 
     out_flush();
@@ -2971,8 +2959,7 @@
 {
     char *errmsg = NULL;
 
-    if (*p_wak == NUL
-	    || check_opt_strings(p_wak, p_wak_values, FALSE) != OK)
+    if (*p_wak == NUL || check_opt_strings(p_wak, p_wak_values, FALSE) != OK)
 	errmsg = e_invalid_argument;
 # ifdef FEAT_MENU
 #  if defined(FEAT_GUI_MOTIF)
@@ -3097,13 +3084,24 @@
 					// need to set P_INSECURE
 {
     char	*errmsg = NULL;
-    int		restore_chartab = FALSE;
     long_u	free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
-    int		value_changed = FALSE;
-#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-    int		did_swaptcap = FALSE;
-#endif
     opt_did_set_cb_T did_set_cb = get_option_did_set_cb(opt_idx);
+    optset_T	args;
+
+    // 'ttytype' is an alias for 'term'.  Both 'term' and 'ttytype' point to
+    // T_NAME.  If 'term' or 'ttytype' is modified, then use the index for the
+    // 'term' option.  Only set the P_ALLOCED flag on 'term'.
+    if (varp == &T_NAME)
+    {
+	opt_idx = findoption((char_u *)"term");
+	if (opt_idx >= 0)
+	{
+	    free_oldval = (get_option_flags(opt_idx) & P_ALLOCED);
+	    did_set_cb = get_option_did_set_cb(opt_idx);
+	}
+    }
+
+    CLEAR_FIELD(args);
 
     // Disallow changing some options from secure mode
     if ((secure
@@ -3117,9 +3115,6 @@
 	errmsg = e_invalid_argument;
     else if (did_set_cb != NULL)
     {
-	optset_T   args;
-
-	CLEAR_FIELD(args);
 	args.os_varp = (char_u *)varp;
 	args.os_idx = opt_idx;
 	args.os_flags = opt_flags;
@@ -3130,22 +3125,10 @@
 	// the new option value.
 	errmsg = did_set_cb(&args);
 
-	// The 'filetype' and 'syntax' option callback functions may change
-	// the os_value_changed field.
-	value_changed = args.os_value_changed;
 	// The 'keymap', 'filetype' and 'syntax' option callback functions
 	// may change the os_value_checked field.
 	*value_checked = args.os_value_checked;
-	// The 'isident', 'iskeyword', 'isprint' and 'isfname' options may
-	// change the character table.  On failure, this needs to be restored.
-	restore_chartab = args.os_restore_chartab;
-#if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-	// The 't_xxx' terminal options may swap the termcap entries.
-	did_swaptcap = args.os_did_swaptcap;
-#endif
     }
-    else if (varp == &T_NAME)			// 'term'
-	errmsg = did_set_term(&opt_idx, &free_oldval);
 
     // If an error is detected, restore the previous value.
     if (errmsg != NULL)
@@ -3153,7 +3136,7 @@
 	free_string_option(*varp);
 	*varp = oldval;
 	// When resetting some values, need to act on it.
-	if (restore_chartab)
+	if (args.os_restore_chartab)
 	    (void)init_chartab();
 	if (varp == &p_hl)
 	    (void)highlight_changed();
@@ -3188,10 +3171,10 @@
 	// Trigger the autocommand only after setting the flags.
 #ifdef FEAT_SYN_HL
 	if (varp == &(curbuf->b_p_syn))
-	    do_syntax_autocmd(value_changed);
+	    do_syntax_autocmd(args.os_value_changed);
 #endif
 	else if (varp == &(curbuf->b_p_ft))
-	    do_filetype_autocmd(varp, opt_flags, value_changed);
+	    do_filetype_autocmd(varp, opt_flags, args.os_value_changed);
 #ifdef FEAT_SPELL
 	if (varp == &(curwin->w_s->b_p_spl))
 	    do_spelllang_source();
@@ -3252,7 +3235,7 @@
     }
 
 #if defined(FEAT_VTP) && defined(FEAT_TERMGUICOLORS)
-    if (did_swaptcap)
+    if (args.os_did_swaptcap)
     {
 	set_termname((char_u *)"win32");
 	init_highlight(TRUE, FALSE);
diff --git a/src/proto/option.pro b/src/proto/option.pro
index a4a2b9f..7b558ed 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -24,68 +24,69 @@
 void set_option_sctx_idx(int opt_idx, int opt_flags, sctx_T script_ctx);
 sctx_T *get_option_sctx(char *name);
 void set_term_option_sctx_idx(char *name, int opt_idx);
-char *did_set_compatible(optset_T *args);
-char *did_set_langremap(optset_T *args);
-char *did_set_langnoremap(optset_T *args);
-char *did_set_undofile(optset_T *args);
-char *did_set_readonly(optset_T *args);
-char *did_set_mousehide(optset_T *args);
-char *did_set_modifiable(optset_T *args);
-char *did_set_eof_eol_fixeol_bomb(optset_T *args);
-char *did_set_binary(optset_T *args);
-char *did_set_buflisted(optset_T *args);
-char *did_set_swapfile(optset_T *args);
-char *did_set_terse(optset_T *args);
-char *did_set_paste(optset_T *args);
-char *did_set_insertmode(optset_T *args);
-char *did_set_ignorecase(optset_T *args);
-char *did_set_hlsearch(optset_T *args);
-char *did_set_scrollbind(optset_T *args);
-char *did_set_previewwindow(optset_T *args);
-char *did_set_smoothscroll(optset_T *args);
-char *did_set_textmode(optset_T *args);
-char *did_set_textauto(optset_T *args);
-char *did_set_lisp(optset_T *args);
-char *did_set_title_icon(optset_T *args);
-char *did_set_modified(optset_T *args);
-char *did_set_shellslash(optset_T *args);
-char *did_set_wrap(optset_T *args);
-char *did_set_equalalways(optset_T *args);
-char *did_set_weirdinvert(optset_T *args);
+char *did_set_arabic(optset_T *args);
+char *did_set_autochdir(optset_T *args);
 char *did_set_ballooneval(optset_T *args);
 char *did_set_balloonevalterm(optset_T *args);
-char *did_set_autochdir(optset_T *args);
+char *did_set_binary(optset_T *args);
+char *did_set_breakat(optset_T *args);
+char *did_set_buflisted(optset_T *args);
+char *did_set_cmdheight(optset_T *args);
+char *did_set_compatible(optset_T *args);
+char *did_set_conceallevel(optset_T *args);
 char *did_set_diff(optset_T *args);
-char *did_set_imdisable(optset_T *args);
-char *did_set_spell(optset_T *args);
-char *did_set_arabic(optset_T *args);
-char *did_set_number_relativenumber(optset_T *args);
-char *did_set_termguicolors(optset_T *args);
-char *did_set_winheight_helpheight(optset_T *args);
-char *did_set_winminheight(optset_T *args);
-char *did_set_winwidth(optset_T *args);
-char *did_set_winminwidth(optset_T *args);
-char *did_set_laststatus(optset_T *args);
-char *did_set_showtabline(optset_T *args);
-char *did_set_linespace(optset_T *args);
+char *did_set_eof_eol_fixeol_bomb(optset_T *args);
+char *did_set_equalalways(optset_T *args);
+char *did_set_foldcolumn(optset_T *args);
 char *did_set_foldlevel(optset_T *args);
 char *did_set_foldminlines(optset_T *args);
 char *did_set_foldnestmax(optset_T *args);
-char *did_set_foldcolumn(optset_T *args);
-char *did_set_shiftwidth_tabstop(optset_T *args);
-char *did_set_maxcombine(optset_T *args);
+char *did_set_hlsearch(optset_T *args);
+char *did_set_ignorecase(optset_T *args);
+char *did_set_imdisable(optset_T *args);
 char *did_set_iminsert(optset_T *args);
-char *did_set_imstyle(optset_T *args);
-char *did_set_window(optset_T *args);
 char *did_set_imsearch(optset_T *args);
-char *did_set_titlelen(optset_T *args);
-char *did_set_cmdheight(optset_T *args);
-char *did_set_updatecount(optset_T *args);
-char *did_set_conceallevel(optset_T *args);
-char *did_set_pyxversion(optset_T *args);
+char *did_set_imstyle(optset_T *args);
+char *did_set_insertmode(optset_T *args);
+char *did_set_langnoremap(optset_T *args);
+char *did_set_langremap(optset_T *args);
+char *did_set_laststatus(optset_T *args);
+char *did_set_linespace(optset_T *args);
+char *did_set_lisp(optset_T *args);
+char *did_set_maxcombine(optset_T *args);
+char *did_set_modifiable(optset_T *args);
+char *did_set_modified(optset_T *args);
+char *did_set_mousehide(optset_T *args);
+char *did_set_number_relativenumber(optset_T *args);
 char *did_set_numberwidth(optset_T *args);
+char *did_set_paste(optset_T *args);
+char *did_set_previewwindow(optset_T *args);
+char *did_set_pyxversion(optset_T *args);
+char *did_set_readonly(optset_T *args);
+char *did_set_scrollbind(optset_T *args);
+char *did_set_shellslash(optset_T *args);
+char *did_set_shiftwidth_tabstop(optset_T *args);
+char *did_set_showtabline(optset_T *args);
+char *did_set_smoothscroll(optset_T *args);
+char *did_set_spell(optset_T *args);
+char *did_set_swapfile(optset_T *args);
+char *did_set_termguicolors(optset_T *args);
+char *did_set_terse(optset_T *args);
+char *did_set_textauto(optset_T *args);
+char *did_set_textmode(optset_T *args);
 char *did_set_textwidth(optset_T *args);
+char *did_set_title_icon(optset_T *args);
+char *did_set_titlelen(optset_T *args);
+char *did_set_undofile(optset_T *args);
 char *did_set_undolevels(optset_T *args);
+char *did_set_updatecount(optset_T *args);
+char *did_set_weirdinvert(optset_T *args);
+char *did_set_window(optset_T *args);
+char *did_set_winheight_helpheight(optset_T *args);
+char *did_set_winminheight(optset_T *args);
+char *did_set_winminwidth(optset_T *args);
+char *did_set_winwidth(optset_T *args);
+char *did_set_wrap(optset_T *args);
 void check_redraw(long_u flags);
 int findoption(char_u *arg);
 getoption_T get_option_value(char_u *name, long *numval, char_u **stringval, int *flagsp, int scope);
@@ -135,7 +136,6 @@
 void change_compatible(int on);
 int option_was_set(char_u *name);
 int reset_option_was_set(char_u *name);
-char *did_set_breakat(optset_T *args);
 int can_bs(int what);
 long get_scrolloff_value(void);
 long get_sidescrolloff_value(void);
diff --git a/src/proto/optionstr.pro b/src/proto/optionstr.pro
index 43f285a..db13f10 100644
--- a/src/proto/optionstr.pro
+++ b/src/proto/optionstr.pro
@@ -100,6 +100,7 @@
 char *did_set_switchbuf(optset_T *args);
 char *did_set_tabline(optset_T *args);
 char *did_set_tagcase(optset_T *args);
+char *did_set_term(optset_T *args);
 char *did_set_term_option(optset_T *args);
 char *did_set_termwinkey(optset_T *args);
 char *did_set_termwinsize(optset_T *args);
diff --git a/src/testdir/test_backspace_opt.vim b/src/testdir/test_backspace_opt.vim
index d70a6d0..ea28803 100644
--- a/src/testdir/test_backspace_opt.vim
+++ b/src/testdir/test_backspace_opt.vim
@@ -138,4 +138,32 @@
   close!
 endfunc
 
+" Test for setting 'backspace' to a number value (for backward compatibility)
+func Test_backspace_number_value()
+  new
+
+  set backspace=0
+  call setline(1, ['one two', 'three four'])
+  call cursor(2, 1)
+  exe "normal! A\<C-W>\<C-U>"
+  call assert_equal('three four', getline(2))
+
+  set backspace=1
+  exe "normal! A\<CR>five\<C-W>\<C-U>\<C-W>\<C-U>"
+  call assert_equal(['one two', 'three four'], getline(1, '$'))
+
+  set backspace=2
+  call cursor(2, 7)
+  exe "normal! ihalf\<C-U>"
+  call assert_equal('three four', getline(2))
+
+  set backspace=3
+  call cursor(2, 7)
+  exe "normal! ihalf\<C-U>"
+  call assert_equal('four', getline(2))
+
+  bw!
+  set backspace&
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_highlight.vim b/src/testdir/test_highlight.vim
index feccf84..a8ef802 100644
--- a/src/testdir/test_highlight.vim
+++ b/src/testdir/test_highlight.vim
@@ -878,6 +878,13 @@
   call assert_match("stop=^[[27h;^[[ r;", HighlightArgs('HlGrp2'))
   hi HlGrp2 stop=NONE
   call assert_notmatch("stop=", HighlightArgs('HlGrp2'))
+  set t_xy=^[foo;
+  set t_xz=^[bar;
+  hi HlGrp3 start=t_xy stop=t_xz
+  let d = hlget('HlGrp3')
+  call assert_equal('^[foo;', d[0].start)
+  call assert_equal('^[bar;', d[0].stop)
+  set t_xy= t_xz=
   hi clear
 endfunc
 
diff --git a/src/testdir/test_python3.vim b/src/testdir/test_python3.vim
index 5de9464..b7140ee 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -375,6 +375,7 @@
         \ ['include', 'ginc', 'linc', ''],
         \ ['dict', 'gdict', 'ldict', ''],
         \ ['thesaurus', 'gtsr', 'ltsr', ''],
+        \ ['thesaurusfunc', 'Gtsrfu', 'Ltsrfu', ''],
         \ ['formatprg', 'gfprg', 'lfprg', ''],
         \ ['errorformat', '%f:%l:%m', '%s-%l-%m', ''],
         \ ['grepprg', 'ggprg', 'lgprg', ''],
@@ -408,9 +409,13 @@
   " Set the global and window-local option values and then clear the
   " window-local option value.
   let wopts = [
+        \ ['fillchars', 'fold:>', 'fold:+', ''],
+        \ ['listchars', 'tab:>>', 'tab:--', ''],
         \ ['scrolloff', 5, 10, -1],
+        \ ['showbreak', '>>', '++', ''],
         \ ['sidescrolloff', 6, 12, -1],
-        \ ['statusline', '%<%f', '%<%F', '']]
+        \ ['statusline', '%<%f', '%<%F', ''],
+        \ ['virtualedit', 'block', 'insert', '']]
   for opt in wopts
     py3 << trim
       pyopt = vim.bindeval("opt")
diff --git a/src/version.c b/src/version.c
index c93499c..3f40fd1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1379,
+/**/
     1378,
 /**/
     1377,