patch 9.2.0386: No scroll/scrollbar support in the tabpanel

Problem:  No scroll/scrollbar support in the tabpanel
Solution: Add support for it (Yasuhiro Matsumoto)

closes: #19979

Signed-off-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/options.txt

@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 9.2.  Last change: 2026 Apr 20
+*options.txt*	For Vim version 9.2.  Last change: 2026 Apr 21
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -9065,6 +9065,23 @@ A jump table for the options with a short description can be found at |Q_op|.
 				tab panel will not be displayed.
 				(default 20)
 
+		scroll		Enable mouse wheel scrolling over the tabpanel
+				area when the tab list exceeds the visible
+				screen height.  The scroll step is controlled
+				by 'mousescroll'.  When disabled (the default),
+				the tabpanel shows the page containing the
+				current tab, with no way to view tabs outside
+				that page.
+
+		scrollbar	Reserve a one-column scrollbar in the tabpanel
+				showing the current scroll position.  The
+				scrollbar uses the |hl-PmenuSbar| and
+				|hl-PmenuThumb| highlight groups for the track
+				and thumb respectively.  Clicking on the
+				scrollbar column jumps the thumb to that
+				position; the thumb can also be dragged.
+				Implies "scroll".
+
 		vert		Use a vertical separator for tabpanel.
 				The vertical separator character is taken from
 				"tpl_vert" in 'fillchars'.

runtime/doc/tabpage.txt

@@ -1,4 +1,4 @@
-*tabpage.txt*	For Vim version 9.2.  Last change: 2026 Feb 14
+*tabpage.txt*	For Vim version 9.2.  Last change: 2026 Apr 21
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -482,6 +482,37 @@ The vertical separator character is taken from "tpl_vert" in 'fillchars'.
 You can customize the appearance of the tab page labels using the highlight
 groups: |hl-TabPanel| |hl-TabPanelSel| |hl-TabPanelFill|
 
+SCROLLING IN THE TABPANEL:				*tabpanel-scroll*
+
+When the total height of the tab list exceeds the visible screen height, the
+tabpanel by default displays the "page" that contains the current tab and
+offers no way to view tabs outside that page.
+
+To make the tabpanel scrollable, add "scroll" to 'tabpanelopt': >
+	:set tabpanelopt+=scroll
+
+With "scroll" enabled, mouse wheel events over the tabpanel area scroll the
+tab list up or down.  The scroll step follows the 'mousescroll' setting.
+Wheel events inside the tabpanel area are consumed by the tabpanel and do not
+trigger |<ScrollWheelUp>| or |<ScrollWheelDown>| mappings.
+
+To additionally show a vertical scrollbar indicating the current scroll
+position, use "scrollbar": >
+	:set tabpanelopt+=scrollbar
+
+The "scrollbar" value implies "scroll".  A one-column scrollbar is reserved at
+the edge of the tabpanel; clicking on the scrollbar column moves the thumb to
+the click position, and the thumb can be dragged to scroll continuously.
+
+When "vert" is combined with "scrollbar", the scrollbar is drawn next to the
+vertical separator, on the panel side.
+
+The scrollbar uses the |hl-PmenuSbar| highlight group for the track and
+|hl-PmenuThumb| for the thumb.
+
+The scroll offset is remembered across redraws but is reset when "scroll" or
+"scrollbar" is toggled off and back on.
+
 ==============================================================================
 6. Setting 'guitablabel'				*setting-guitablabel*
 

runtime/doc/tags

@@ -10889,6 +10889,7 @@ tabpagebuflist()	builtin.txt	/*tabpagebuflist()*
 tabpagenr()	builtin.txt	/*tabpagenr()*
 tabpagewinnr()	builtin.txt	/*tabpagewinnr()*
 tabpanel	tabpage.txt	/*tabpanel*
+tabpanel-scroll	tabpage.txt	/*tabpanel-scroll*
 tag	tagsrch.txt	/*tag*
 tag-!	tagsrch.txt	/*tag-!*
 tag-binary-search	tagsrch.txt	/*tag-binary-search*

runtime/doc/version9.txt

@@ -52616,6 +52616,9 @@ Other ~
 - Allow mouse clickable regions in the 'statusline', 'tabline' and the
   'tabpanel' using the |stl-%[FuncName]| atom.
 - Enable reflow support in the |:terminal|.
+- Added "scroll" and "scrollbar" sub-options to 'tabpanelopt' so the
+  tabpanel can scroll when the tab list exceeds the visible screen
+  height.
 
 Platform specific ~
 -----------------

src/buffer.c

@@ -4946,6 +4946,9 @@ build_stl_str_hl_local(
 		    maxwid = 50;
 	    }
 	}
+	// Keep the uncapped value for %N[FuncName] click-region IDs; the 50
+	// cap below applies only when minwid is used as a padding width.
+	int raw_minwid = minwid * l;
 	minwid = (minwid > 50 ? 50 : minwid) * l;
 	if (*s == '(')
 	{
@@ -5306,7 +5309,11 @@ build_stl_str_hl_local(
 		{
 		    stl_items[curitem].stl_type = ClickFunc;
 		    stl_items[curitem].stl_start = p;
-		    stl_items[curitem].stl_minwid = minwid;
+		    // The stl_minwid field is overloaded: it may be the
+		    // "min" part of %<min>.<max> used for padding, or an
+		    // identifier passed to the %N[FuncName] callback.  Store
+		    // the uncapped value so IDs above 50 are preserved.
+		    stl_items[curitem].stl_minwid = raw_minwid;
 		    stl_items[curitem].stl_clickfunc =
 					      vim_strnsave(s, rb - s);
 		    s = rb + 1;

src/mouse.c

@@ -240,6 +240,9 @@ do_mouse(
     int		in_status_line;	// mouse in status line
     static int	in_tab_line = FALSE; // mouse clicked in tab line
     static int	in_tabpanel = FALSE; // mouse clicked in tabpanel
+#ifdef FEAT_TABPANEL
+    static bool	in_tabpanel_scrollbar = false; // dragging tabpanel scrollbar
+#endif
     int		in_sep_line;	// mouse in vertical separator line
     int		c1, c2;
 #if defined(FEAT_FOLDING)
@@ -346,6 +349,9 @@ do_mouse(
 	got_click = TRUE;
 	in_tab_line = FALSE;
 	in_tabpanel = FALSE;
+#ifdef FEAT_TABPANEL
+	in_tabpanel_scrollbar = false;
+#endif
     }
     else
     {
@@ -354,15 +360,31 @@ do_mouse(
 	if (!is_drag)			// release, reset got_click
 	{
 	    got_click = FALSE;
-	    if (in_tab_line || in_tabpanel)
+	    if (in_tab_line || in_tabpanel
+#ifdef FEAT_TABPANEL
+		    || in_tabpanel_scrollbar
+#endif
+		    )
 	    {
 		in_tab_line = FALSE;
 		in_tabpanel = FALSE;
+#ifdef FEAT_TABPANEL
+		in_tabpanel_scrollbar = false;
+#endif
 		return FALSE;
 	    }
 	}
     }
 
+#ifdef FEAT_TABPANEL
+    // Continue a scrollbar drag before any tab-selection handling.
+    if (is_drag && in_tabpanel_scrollbar)
+    {
+	tabpanel_drag_scrollbar(mouse_row);
+	return FALSE;
+    }
+#endif
+
     // CTRL right mouse button does CTRL-T
     if (is_click && (mod_mask & MOD_MASK_CTRL) && which_button == MOUSE_RIGHT)
     {
@@ -494,6 +516,15 @@ do_mouse(
     if (mouse_col < firstwin->w_wincol
 		|| mouse_col >= firstwin->w_wincol + topframe->fr_width)
     {
+	// A click on the scrollbar column starts a drag interaction and
+	// preempts tab-selection.
+	if (is_click && !is_drag && mouse_on_tabpanel_scrollbar())
+	{
+	    in_tabpanel_scrollbar = TRUE;
+	    tabpanel_drag_scrollbar(mouse_row);
+	    return FALSE;
+	}
+
 	// Dispatch 'tabpanel' %[FuncName] click regions before falling through
 	// to tab-page selection.  On drag events fall through to the normal
 	// tab-drag handling.
@@ -1276,6 +1307,17 @@ ins_mousescroll(int dir)
     cap.oap = &oa;
     cap.arg = dir;
 
+#ifdef FEAT_TABPANEL
+    if (mouse_row >= 0 && mouse_col >= 0
+	    && (dir == MSCR_UP || dir == MSCR_DOWN)
+	    && mouse_on_tabpanel())
+    {
+	(void)tabpanel_scroll(dir == MSCR_UP ? 1 : -1,
+		mouse_vert_step > 0 ? mouse_vert_step : 3);
+	return;
+    }
+#endif
+
     switch (dir)
     {
 	case MSCR_UP:
@@ -2409,6 +2451,17 @@ nv_mousescroll(cmdarg_T *cap)
 {
     win_T   *old_curwin = curwin;
 
+#ifdef FEAT_TABPANEL
+    if (mouse_row >= 0 && mouse_col >= 0
+	    && (cap->arg == MSCR_UP || cap->arg == MSCR_DOWN)
+	    && mouse_on_tabpanel())
+    {
+	(void)tabpanel_scroll(cap->arg == MSCR_UP ? 1 : -1,
+		mouse_vert_step > 0 ? mouse_vert_step : 3);
+	return;
+    }
+#endif
+
     if (mouse_row >= 0 && mouse_col >= 0)
     {
 	// Find the window at the mouse pointer coordinates.

src/proto/tabpanel.pro

@@ -4,4 +4,8 @@ int tabpanel_width(void);
 int tabpanel_leftcol(void);
 void draw_tabpanel(void);
 int get_tabpagenr_on_tabpanel(void);
+bool mouse_on_tabpanel(void);
+bool mouse_on_tabpanel_scrollbar(void);
+bool tabpanel_drag_scrollbar(int screen_row);
+bool tabpanel_scroll(int dir, int count);
 /* vim: set ft=c : */

src/tabpanel.c

@@ -20,6 +20,7 @@ static void do_by_tplmode(int tplmode, int col_start, int col_end,
 static void tabpanel_free_click_regions(void);
 static void tabpanel_append_click_regions(stl_clickrec_T *clicktab,
 	char_u *buf, int row, int col_start, int col_end, int tabnr);
+static void draw_tabpanel_scrollbar(int screen_col);
 
 // set pcurtab_row. don't redraw tabpanel.
 #define TPLMODE_GET_CURTAB_ROW	0
@@ -31,6 +32,7 @@ static void tabpanel_append_click_regions(stl_clickrec_T *clicktab,
 #define TPL_FILLCHAR		' '
 
 #define VERT_LEN		1
+#define SCROLL_LEN		1
 
 // tpl_align's values
 #define ALIGN_LEFT		0
@@ -40,7 +42,12 @@ static char_u *opt_name = (char_u *)"tabpanel";
 static int opt_scope = OPT_LOCAL;
 static int tpl_align = ALIGN_LEFT;
 static int tpl_columns = 20;
-static int tpl_is_vert = FALSE;
+static bool tpl_is_vert = false;
+static bool tpl_scroll = false;
+static bool tpl_scrollbar = false;
+static int tpl_scroll_offset = 0;
+static int tpl_total_rows = 0;
+static int tpl_scrollbar_col = -1;	// screen column of scrollbar, -1 if none
 
 typedef struct {
     win_T   *wp;
@@ -61,7 +68,9 @@ tabpanelopt_changed(void)
     char_u	*p;
     int		new_align = ALIGN_LEFT;
     long	new_columns = 20;
-    int		new_is_vert = FALSE;
+    bool	new_is_vert = false;
+    bool	new_scroll = false;
+    bool	new_scrollbar = false;
 
     p = p_tplo;
     while (*p != NUL)
@@ -92,7 +101,18 @@ tabpanelopt_changed(void)
 	else if (STRNCMP(p, "vert", 4) == 0)
 	{
 	    p += 4;
-	    new_is_vert = TRUE;
+	    new_is_vert = true;
+	}
+	else if (STRNCMP(p, "scrollbar", 9) == 0)
+	{
+	    p += 9;
+	    new_scrollbar = true;
+	    new_scroll = true;
+	}
+	else if (STRNCMP(p, "scroll", 6) == 0)
+	{
+	    p += 6;
+	    new_scroll = true;
 	}
 
 	if (*p != ',' && *p != NUL)
@@ -104,6 +124,10 @@ tabpanelopt_changed(void)
     tpl_align = new_align;
     tpl_columns = new_columns;
     tpl_is_vert = new_is_vert;
+    if (tpl_scroll != new_scroll)
+	tpl_scroll_offset = 0;
+    tpl_scroll = new_scroll;
+    tpl_scrollbar = new_scrollbar;
 
     shell_new_columns();
     return OK;
@@ -266,39 +290,65 @@ draw_tabpanel(void)
     // Reset got_int to avoid build_stl_str_hl() isn't evaluated.
     got_int = FALSE;
 
+    int sb_len = tpl_scrollbar ? SCROLL_LEN : 0;
+    int sb_screen_col = -1;
+
     if (tpl_is_vert)
     {
 	if (is_right)
 	{
 	    // draw main contents in tabpanel
-	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, VERT_LEN,
+	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, VERT_LEN + sb_len,
 		    maxwidth - VERT_LEN, &curtab_row, NULL);
-	    do_by_tplmode(TPLMODE_REDRAW, VERT_LEN, maxwidth, &curtab_row,
-		    NULL);
+	    do_by_tplmode(TPLMODE_REDRAW, VERT_LEN + sb_len, maxwidth,
+		    &curtab_row, NULL);
 	    // draw vert separator in tabpanel
 	    for (vsrow = 0; vsrow < Rows; vsrow++)
 		screen_putchar(curwin->w_fill_chars.tpl_vert, vsrow,
 			topframe->fr_width, vs_attr);
+	    if (tpl_scrollbar)
+		sb_screen_col = topframe->fr_width + VERT_LEN;
 	}
 	else
 	{
 	    // draw main contents in tabpanel
-	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, 0, maxwidth - VERT_LEN,
-		    &curtab_row, NULL);
-	    do_by_tplmode(TPLMODE_REDRAW, 0, maxwidth - VERT_LEN,
+	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, 0,
+		    maxwidth - VERT_LEN - sb_len, &curtab_row, NULL);
+	    do_by_tplmode(TPLMODE_REDRAW, 0, maxwidth - VERT_LEN - sb_len,
 		    &curtab_row, NULL);
 	    // draw vert separator in tabpanel
 	    for (vsrow = 0; vsrow < Rows; vsrow++)
 		screen_putchar(curwin->w_fill_chars.tpl_vert, vsrow,
 			maxwidth - VERT_LEN, vs_attr);
+	    if (tpl_scrollbar)
+		sb_screen_col = maxwidth - VERT_LEN - SCROLL_LEN;
 	}
     }
     else
     {
-	do_by_tplmode(TPLMODE_GET_CURTAB_ROW, 0, maxwidth, &curtab_row, NULL);
-	do_by_tplmode(TPLMODE_REDRAW, 0, maxwidth, &curtab_row, NULL);
+	if (is_right)
+	{
+	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, sb_len, maxwidth,
+		    &curtab_row, NULL);
+	    do_by_tplmode(TPLMODE_REDRAW, sb_len, maxwidth, &curtab_row, NULL);
+	    if (tpl_scrollbar)
+		sb_screen_col = topframe->fr_width;
+	}
+	else
+	{
+	    do_by_tplmode(TPLMODE_GET_CURTAB_ROW, 0, maxwidth - sb_len,
+		    &curtab_row, NULL);
+	    do_by_tplmode(TPLMODE_REDRAW, 0, maxwidth - sb_len,
+		    &curtab_row, NULL);
+	    if (tpl_scrollbar)
+		sb_screen_col = maxwidth - SCROLL_LEN;
+	}
     }
 
+    tpl_scrollbar_col = sb_screen_col;
+    if (sb_screen_col >= 0)
+	draw_tabpanel_scrollbar(sb_screen_col);
+
     got_int |= saved_got_int;
 
     // A user function may reset KeyTyped, restore it.
@@ -556,8 +606,13 @@ do_by_tplmode(
     args.col_end = col_end;
 
     if (tplmode != TPLMODE_GET_CURTAB_ROW && args.maxrow > 0)
-	while (args.offsetrow + args.maxrow <= *pcurtab_row)
-	    args.offsetrow += args.maxrow;
+    {
+	if (tpl_scroll)
+	    args.offsetrow = tpl_scroll_offset;
+	else
+	    while (args.offsetrow + args.maxrow <= *pcurtab_row)
+		args.offsetrow += args.maxrow;
+    }
 
     tp = first_tabpage;
 
@@ -579,8 +634,13 @@ do_by_tplmode(
 	    if (tplmode == TPLMODE_GET_CURTAB_ROW)
 	    {
 		*pcurtab_row = row;
-		do_unlet((char_u *)"g:actual_curtabpage", TRUE);
-		break;
+		// When scroll mode is active keep iterating so tpl_total_rows
+		// receives the true content height; otherwise bail out early.
+		if (!tpl_scroll)
+		{
+		    do_unlet((char_u *)"g:actual_curtabpage", TRUE);
+		    break;
+		}
 	    }
 	}
 	else
@@ -608,7 +668,8 @@ do_by_tplmode(
 		stl_hlrec_T	*tabtab;
 		stl_clickrec_T	*clicktab = NULL;
 
-		if (args.maxrow <= row - args.offsetrow)
+		if (tplmode != TPLMODE_GET_CURTAB_ROW
+			&& args.maxrow <= row - args.offsetrow)
 		    break;
 
 		buf[0] = NUL;
@@ -677,6 +738,142 @@ do_by_tplmode(
     // fill the area of TabPanelFill.
     screen_fill_tailing_area(tplmode, MAX(row - args.offsetrow, 0), args.maxrow,
 	    args.col_start, args.col_end, attr_tplf);
+
+    // Capture the true content height during the GET_CURTAB_ROW pass, which
+    // ignores maxrow and therefore walks every tab.  REDRAW stops at the
+    // visible edge so its "row" is clamped and unusable here.
+    if (tplmode == TPLMODE_GET_CURTAB_ROW && tpl_scroll)
+	tpl_total_rows = row;
+}
+
+/*
+ * Draw the tabpanel scrollbar (track + thumb) at screen column 'screen_col'.
+ * The scrollbar spans the full screen height.  The thumb position and size
+ * are derived from tpl_scroll_offset, tpl_total_rows and Rows.
+ */
+    static void
+draw_tabpanel_scrollbar(int screen_col)
+{
+    int attr_sb = HL_ATTR(HLF_PSB);
+    int attr_thumb = HL_ATTR(HLF_PST);
+    int thumb_top = 0;
+    int thumb_height = 0;
+
+    if (tpl_total_rows > Rows && Rows > 0)
+    {
+	thumb_height = Rows * Rows / tpl_total_rows;
+	if (thumb_height < 1)
+	    thumb_height = 1;
+	thumb_top = Rows * tpl_scroll_offset / tpl_total_rows;
+	if (thumb_top + thumb_height > Rows)
+	    thumb_top = Rows - thumb_height;
+	if (thumb_top < 0)
+	    thumb_top = 0;
+    }
+
+    for (int r = 0; r < Rows; r++)
+    {
+	bool on_thumb = thumb_height > 0
+	    && r >= thumb_top && r < thumb_top + thumb_height;
+	screen_putchar(TPL_FILLCHAR, r, screen_col,
+		on_thumb ? attr_thumb : attr_sb);
+    }
+}
+
+/*
+ * Return true if the mouse is currently positioned over the tabpanel area.
+ */
+    bool
+mouse_on_tabpanel(void)
+{
+    if (tabpanel_width() == 0)
+	return false;
+    return mouse_col < firstwin->w_wincol
+	|| mouse_col >= firstwin->w_wincol + topframe->fr_width;
+}
+
+/*
+ * Return true if the mouse is currently on the scrollbar column.
+ * The scrollbar column is tracked by draw_tabpanel() and is -1 when the
+ * scrollbar is not enabled or not yet drawn.
+ */
+    bool
+mouse_on_tabpanel_scrollbar(void)
+{
+    return tpl_scrollbar && tpl_scrollbar_col >= 0
+	&& mouse_col == tpl_scrollbar_col;
+}
+
+/*
+ * Move the scrollbar thumb so it is vertically centred on screen row
+ * 'screen_row', updating tpl_scroll_offset accordingly.  Used for both
+ * initial clicks and subsequent drag events.
+ * Returns true if the event was consumed (offset changed or not).
+ */
+    bool
+tabpanel_drag_scrollbar(int screen_row)
+{
+    int thumb_height;
+    int max_offset;
+    int track_range;
+    int thumb_top;
+    int new_offset;
+
+    if (!tpl_scrollbar || Rows <= 0 || tpl_total_rows <= Rows)
+	return false;
+
+    thumb_height = Rows * Rows / tpl_total_rows;
+    if (thumb_height < 1)
+	thumb_height = 1;
+    track_range = Rows - thumb_height;
+    if (track_range <= 0)
+	return true;
+
+    max_offset = tpl_total_rows - Rows;
+    thumb_top = screen_row - thumb_height / 2;
+    if (thumb_top < 0)
+	thumb_top = 0;
+    if (thumb_top > track_range)
+	thumb_top = track_range;
+
+    new_offset = thumb_top * max_offset / track_range;
+    if (new_offset != tpl_scroll_offset)
+    {
+	tpl_scroll_offset = new_offset;
+	redraw_tabpanel = TRUE;
+    }
+    return true;
+}
+
+/*
+ * Scroll the tabpanel by 'count' rows in direction 'dir' (1 = down, -1 = up).
+ * Returns true if the offset changed and a redraw was scheduled.
+ * Has no effect unless 'tabpanelopt' contains "scroll".
+ */
+    bool
+tabpanel_scroll(int dir, int count)
+{
+    int max_offset;
+    int new_offset;
+
+    if (!tpl_scroll || tabpanel_width() == 0)
+	return false;
+
+    max_offset = tpl_total_rows - Rows;
+    if (max_offset < 0)
+	max_offset = 0;
+
+    new_offset = tpl_scroll_offset + (dir > 0 ? count : -count);
+    if (new_offset < 0)
+	new_offset = 0;
+    if (new_offset > max_offset)
+	new_offset = max_offset;
+    if (new_offset == tpl_scroll_offset)
+	return false;
+
+    tpl_scroll_offset = new_offset;
+    redraw_tabpanel = TRUE;
+    return true;
 }
 
 #endif // FEAT_TABPANEL

src/testdir/test_tabpanel.vim

@@ -962,8 +962,68 @@ func Test_tabpanel_large_columns()
   call assert_fails(':set tabpanelopt=columns:-1', 'E474:')
 endfunc
 
+func Test_tabpanel_scrollopt_accepted()
+  " 'scroll' / 'scrollbar' must be accepted in 'tabpanelopt'.
+  set tabpanelopt=scroll
+  call assert_equal('scroll', &tabpanelopt)
+  set tabpanelopt=scrollbar
+  call assert_equal('scrollbar', &tabpanelopt)
+
+  " Combination with other values.
+  set tabpanelopt=align:right,scroll
+  call assert_equal('align:right,scroll', &tabpanelopt)
+  set tabpanelopt=columns:15,vert,scrollbar
+  call assert_equal('columns:15,vert,scrollbar', &tabpanelopt)
+  set tabpanelopt=align:right,columns:12,vert,scrollbar
+  call assert_equal('align:right,columns:12,vert,scrollbar', &tabpanelopt)
+
+  " Unknown values must still fail.
+  call assert_fails(':set tabpanelopt=scrol', 'E474:')
+  call assert_fails(':set tabpanelopt=scrollbarx', 'E474:')
+
+  call s:reset()
+endfunc
+
+func Test_tabpanel_scroll_many_tabs()
+  let save_lines = &lines
+  let save_showtabpanel = &showtabpanel
+  let save_tabpanelopt = &tabpanelopt
+
+  " Make the screen short so the tab list exceeds the visible height.
+  set lines=8
+  set showtabpanel=2
+  set tabpanelopt=scroll
+  for i in range(20)
+    tabnew
+  endfor
+
+  " Should not crash with many tabs and scroll enabled.
+  redraw!
+
+  " Switching to scrollbar resets the offset but must also not crash.
+  set tabpanelopt=scrollbar
+  redraw!
+
+  " Disabling scroll returns to normal behavior.
+  set tabpanelopt=
+  redraw!
+
+  " Right alignment with scrollbar.
+  set tabpanelopt=align:right,scrollbar
+  redraw!
+
+  " Vertical separator with scrollbar.
+  set tabpanelopt=columns:10,vert,scrollbar
+  redraw!
+
+  " Cleanup.
+  %bwipeout!
+  let &tabpanelopt = save_tabpanelopt
+  let &showtabpanel = save_showtabpanel
+  let &lines = save_lines
+endfunc
+
 func Test_tabpanel_variable_height()
-  CheckFeature tabpanel
 
   let save_lines = &lines
   let save_showtabpanel = &showtabpanel

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    386,
 /**/
     385,
 /**/