15 files changed, 110 insertions, 223 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 02aba05ccb4..817f8c77d97 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3200,48 +3200,17 @@ enum tab_bar_item_idx
   /* Caption.  */
   TAB_BAR_ITEM_CAPTION,
 
-  /* Image(s) to display.  This is either a single image specification
-     or a vector of specifications.  */
-  TAB_BAR_ITEM_IMAGES,
-
   /* The binding.  */
   TAB_BAR_ITEM_BINDING,
 
-  /* Button type.  One of nil (default button), t (a separator),
-     `:radio', or `:toggle'.  The latter two currently do nothing.  */
-  TAB_BAR_ITEM_TYPE,
-
   /* Help string.  */
   TAB_BAR_ITEM_HELP,
 
-  /* Icon file name of right to left image when an RTL locale is used.  */
-  TAB_BAR_ITEM_RTL_IMAGE,
-
-  /* Label to show when text labels are enabled.  */
-  TAB_BAR_ITEM_LABEL,
-
-  /* If we shall show the label only below the icon and not beside it.  */
-  TAB_BAR_ITEM_VERT_ONLY,
-
   /* Sentinel = number of slots in tab_bar_items occupied by one
      tab-bar item.  */
   TAB_BAR_ITEM_NSLOTS
 };
 
-
-/* An enumeration for the different images that can be specified
-   for a tab-bar item.  */
-
-enum tab_bar_item_image
-{
-  TAB_BAR_IMAGE_ENABLED_SELECTED,
-  TAB_BAR_IMAGE_ENABLED_DESELECTED,
-  TAB_BAR_IMAGE_DISABLED_SELECTED,
-  TAB_BAR_IMAGE_DISABLED_DESELECTED
-};
-
-#define DEFAULT_TAB_BAR_LABEL_SIZE 14
-
 /* Default values of the above variables.  */
 
 #define DEFAULT_TAB_BAR_BUTTON_MARGIN 4
diff --git a/src/dispnew.c b/src/dispnew.c
index 7e89a855bbb..4cf131522ec 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -456,8 +456,10 @@ adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y
               || (row == matrix->rows + dim.height - 1
                   && window_wants_mode_line (w))
               || (row == matrix->rows && matrix->tab_line_p)
-              || (row == matrix->rows && !matrix->tab_line_p && matrix->header_line_p)
-              || (row == (matrix->rows + 1) && matrix->tab_line_p && matrix->header_line_p))
+              || (row == matrix->rows
+                  && !matrix->tab_line_p && matrix->header_line_p)
+              || (row == (matrix->rows + 1)
+                  && matrix->tab_line_p && matrix->header_line_p))
             {
               row->glyphs[TEXT_AREA]
                 = row->glyphs[LEFT_MARGIN_AREA];
@@ -504,8 +506,10 @@ adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y
               if ((row == matrix->rows + dim.height - 1
                    && !(w && window_wants_mode_line (w)))
                   || (row == matrix->rows && matrix->tab_line_p)
-                  || (row == matrix->rows && !matrix->tab_line_p && matrix->header_line_p)
-                  || (row == (matrix->rows + 1) && matrix->tab_line_p && matrix->header_line_p))
+                  || (row == matrix->rows
+                      && !matrix->tab_line_p && matrix->header_line_p)
+                  || (row == (matrix->rows + 1)
+                      && matrix->tab_line_p && matrix->header_line_p))
                 {
                   row->glyphs[TEXT_AREA]
                     = row->glyphs[LEFT_MARGIN_AREA];
@@ -3550,7 +3554,8 @@ update_window (struct window *w, bool force_p)
       /* Try reusing part of the display by copying.  */
       if (row < end && !desired_matrix->no_scrolling_p)
         {
-          int rc = scrolling_window (w, (tab_line_row != NULL ? 1 : 0) + (header_line_row != NULL ? 1 : 0));
+          int rc = scrolling_window (w, (tab_line_row != NULL ? 1 : 0)
+                                     + (header_line_row != NULL ? 1 : 0));
           if (rc < 0)
             {
               /* All rows were found to be equal.  */
@@ -5428,7 +5433,8 @@ buffer_posn_from_coords (struct window *w, int *x, int *y, struct display_pos *p
      start position, i.e. it excludes the header-line row, but
      MATRIX_ROW includes the header-line row.  Adjust for a possible
      header-line row.  */
-  it_vpos = it.vpos + window_wants_header_line (w) + window_wants_tab_line (w);
+  it_vpos = it.vpos + window_wants_header_line (w)
+    + window_wants_tab_line (w);
   if (it_vpos < w->current_matrix->nrows
       && (row = MATRIX_ROW (w->current_matrix, it_vpos),
           row->enabled_p))
@@ -5675,7 +5681,8 @@ handle_window_change_signal (int sig)
              structures now.  Let that be done later outside of the
              signal handler.  */
           change_frame_size (XFRAME (frame), width,
-                             height - FRAME_MENU_BAR_LINES (XFRAME (frame)) - FRAME_TAB_BAR_LINES (XFRAME (frame)),
+                             height - FRAME_MENU_BAR_LINES (XFRAME (frame))
+                             - FRAME_TAB_BAR_LINES (XFRAME (frame)),
                              0, 1, 0, 0);
     }
   }
@@ -6355,7 +6362,8 @@ init_display_interactive (void)
     change_frame_size (XFRAME (selected_frame),
                        FrameCols (t->display_info.tty),
                        FrameRows (t->display_info.tty)
-                       - FRAME_MENU_BAR_LINES (f) - FRAME_TAB_BAR_LINES (f), 0, 0, 1, 0);
+                       - FRAME_MENU_BAR_LINES (f)
+                       - FRAME_TAB_BAR_LINES (f), 0, 0, 1, 0);
 
     /* Delete the initial terminal. */
     if (--initial_terminal->reference_count == 0
diff --git a/src/frame.c b/src/frame.c
index 5caa3f46714..d72dfec0cf8 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -1191,10 +1191,12 @@ make_terminal_frame (struct terminal *terminal)
 
   FRAME_MENU_BAR_LINES (f) = NILP (Vmenu_bar_mode) ? 0 : 1;
   FRAME_TAB_BAR_LINES (f) = NILP (Vtab_bar_mode) ? 0 : 1;
-  FRAME_LINES (f) = FRAME_LINES (f) - FRAME_MENU_BAR_LINES (f) - FRAME_TAB_BAR_LINES (f);
+  FRAME_LINES (f) = FRAME_LINES (f) - FRAME_MENU_BAR_LINES (f)
+    - FRAME_TAB_BAR_LINES (f);
   FRAME_MENU_BAR_HEIGHT (f) = FRAME_MENU_BAR_LINES (f) * FRAME_LINE_HEIGHT (f);
   FRAME_TAB_BAR_HEIGHT (f) = FRAME_TAB_BAR_LINES (f) * FRAME_LINE_HEIGHT (f);
-  FRAME_TEXT_HEIGHT (f) = FRAME_TEXT_HEIGHT (f) - FRAME_MENU_BAR_HEIGHT (f) - FRAME_TAB_BAR_HEIGHT (f);
+  FRAME_TEXT_HEIGHT (f) = FRAME_TEXT_HEIGHT (f) - FRAME_MENU_BAR_HEIGHT (f)
+    - FRAME_TAB_BAR_HEIGHT (f);
 
   /* Set the top frame to the newly created frame.  */
   if (FRAMEP (FRAME_TTY (f)->top_frame)
@@ -1316,7 +1318,8 @@ affects all frames on the same terminal device.  */)
   {
     int width, height;
     get_tty_size (fileno (FRAME_TTY (f)->input), &width, &height);
-    adjust_frame_size (f, width, height - FRAME_MENU_BAR_LINES (f) - FRAME_TAB_BAR_LINES (f),
+    adjust_frame_size (f, width, height - FRAME_MENU_BAR_LINES (f)
+                       - FRAME_TAB_BAR_LINES (f),
                        5, 0, Qterminal_frame);
   }
 
@@ -3444,23 +3447,6 @@ to `frame-height'). */)
     return make_fixnum (FRAME_TOTAL_LINES (f));
 }
 
-DEFUN ("tab-bar-pixel-width", Ftab_bar_pixel_width,
-       Stab_bar_pixel_width, 0, 1, 0,
-       doc: /* Return width in pixels of FRAME's tab bar.
-The result is greater than zero only when the tab bar is on the left
-or right side of FRAME.  If FRAME is omitted or nil, the selected frame
-is used.  */)
-  (Lisp_Object frame)
-{
-#ifdef FRAME_TABBAR_WIDTH
-  struct frame *f = decode_any_frame (frame);
-
-  if (FRAME_WINDOW_P (f))
-    return make_fixnum (FRAME_TABBAR_WIDTH (f));
-#endif
-  return make_fixnum (0);
-}
-
 DEFUN ("tool-bar-pixel-width", Ftool_bar_pixel_width,
        Stool_bar_pixel_width, 0, 1, 0,
        doc: /* Return width in pixels of FRAME's tool bar.
@@ -5464,8 +5450,8 @@ On Nextstep, this just calls `ns-parse-geometry'.  */)
 #define DEFAULT_COLS 80
 
 long
-gui_figure_window_size (struct frame *f, Lisp_Object parms, bool tabbar_p, bool toolbar_p,
-                        int *x_width, int *x_height)
+gui_figure_window_size (struct frame *f, Lisp_Object parms, bool tabbar_p,
+                        bool toolbar_p, int *x_width, int *x_height)
 {
   Lisp_Object height, width, user_size, top, left, user_position;
   long window_prompting = 0;
@@ -6425,7 +6411,6 @@ iconify the top level frame instead.  */);
   defsubr (&Sframe_internal_border_width);
   defsubr (&Sright_divider_width);
   defsubr (&Sbottom_divider_width);
-  defsubr (&Stab_bar_pixel_width);
   defsubr (&Stool_bar_pixel_width);
   defsubr (&Sset_frame_height);
   defsubr (&Sset_frame_width);
diff --git a/src/fringe.c b/src/fringe.c
index 2735ae70f94..22f3bdc2ba8 100644
--- a/src/fringe.c
+++ b/src/fringe.c
@@ -634,7 +634,8 @@ draw_fringe_bitmap_1 (struct window *w, struct glyph_row *row, int left_p, int o
   /* Clear left fringe if no bitmap to draw or if bitmap doesn't fill
      the fringe.  */
   p.bx = -1;
-  header_line_height = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
+  header_line_height = WINDOW_TAB_LINE_HEIGHT (w)
+                       + WINDOW_HEADER_LINE_HEIGHT (w);
   p.by = WINDOW_TO_FRAME_PIXEL_Y (w, max (header_line_height, row->y));
   p.ny = row->visible_height;
   if (left_p)
@@ -1091,7 +1092,8 @@ update_window_fringes (struct window *w, bool keep_current_p)
               struct glyph_row *row1;
               int top_ind_max_y;
 
-              top_ind_min_y = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
+              top_ind_min_y = WINDOW_TAB_LINE_HEIGHT (w)
+                              + WINDOW_HEADER_LINE_HEIGHT (w);
               top_ind_max_y = top_ind_min_y + fb->height;
               if (top_ind_max_y > yb)
                 top_ind_max_y = yb;
@@ -1148,8 +1150,10 @@ update_window_fringes (struct window *w, bool keep_current_p)
 
               bot_ind_max_y = row->y + row->visible_height;
               bot_ind_min_y = bot_ind_max_y - fb->height;
-              if (bot_ind_min_y < WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w))
-                bot_ind_min_y = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
+              if (bot_ind_min_y < WINDOW_TAB_LINE_HEIGHT (w)
+                                  + WINDOW_HEADER_LINE_HEIGHT (w))
+                bot_ind_min_y = WINDOW_TAB_LINE_HEIGHT (w)
+                                + WINDOW_HEADER_LINE_HEIGHT (w);
 
               for (y = row->y, rn = bot_ind_rn - 1;
                    y >= bot_ind_min_y && rn >= 0;
diff --git a/src/gtkutil.c b/src/gtkutil.c
index 8a2fc3aa16d..16d765533a7 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -951,8 +951,8 @@ xg_frame_set_char_size (struct frame *f, int width, int height)
   Lisp_Object fullscreen = get_frame_param (f, Qfullscreen);
   gint gwidth, gheight;
   int totalheight
-    = pixelheight + FRAME_TOOLBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f) + FRAME_MENUBAR_HEIGHT (f);
-  int totalwidth = pixelwidth + FRAME_TABBAR_WIDTH (f) + FRAME_TOOLBAR_WIDTH (f);
+    = pixelheight + FRAME_TOOLBAR_HEIGHT (f) + FRAME_MENUBAR_HEIGHT (f);
+  int totalwidth = pixelwidth + FRAME_TOOLBAR_WIDTH (f);
 
   if (FRAME_PIXEL_HEIGHT (f) == 0)
     return;
@@ -1437,9 +1437,9 @@ x_wm_set_size_hint (struct frame *f, long int flags, bool user_position)
   /* Use one row/col here so base_height/width does not become zero.
      Gtk+ and/or Unity on Ubuntu 12.04 can't handle it.
      Obviously this makes the row/col value displayed off by 1.  */
-  base_width = FRAME_TEXT_COLS_TO_PIXEL_WIDTH (f, 1) + FRAME_TABBAR_WIDTH (f) + FRAME_TOOLBAR_WIDTH (f);
+  base_width = FRAME_TEXT_COLS_TO_PIXEL_WIDTH (f, 1) + FRAME_TOOLBAR_WIDTH (f);
   base_height = FRAME_TEXT_LINES_TO_PIXEL_HEIGHT (f, 1)
-    + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f) + FRAME_TOOLBAR_HEIGHT (f);
+    + FRAME_MENUBAR_HEIGHT (f) + FRAME_TOOLBAR_HEIGHT (f);
 
   size_hints.base_width = base_width;
   size_hints.base_height = base_height;
diff --git a/src/keyboard.c b/src/keyboard.c
index 51040f067df..8b7c473690d 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -2385,7 +2385,8 @@ read_char (int commandflag, Lisp_Object map,
       if (used_mouse_menu
           /* Also check was_disabled so last-nonmenu-event won't return
              a bad value when submenus are involved.  (Bug#447)  */
-          && (EQ (c, Qtool_bar) || EQ (c, Qtab_bar) || EQ (c, Qmenu_bar) || was_disabled))
+          && (EQ (c, Qtool_bar) || EQ (c, Qtab_bar) || EQ (c, Qmenu_bar)
+              || was_disabled))
         *used_mouse_menu = true;
 
       goto reread_for_input_method;
@@ -5043,14 +5044,15 @@ make_lispy_position (struct frame *f, Lisp_Object x, Lisp_Object y,
       /* For mode line and header line clicks, return X, Y relative to
          the left window edge.  Use mode_line_string to look for a
          string on the click position.  */
-      else if (part == ON_MODE_LINE || part == ON_TAB_LINE || part == ON_HEADER_LINE)
+      else if (part == ON_MODE_LINE || part == ON_TAB_LINE
+               || part == ON_HEADER_LINE)
         {
           Lisp_Object string;
           ptrdiff_t charpos;
 
           posn = (part == ON_MODE_LINE ? Qmode_line
-                  : (part == ON_TAB_LINE ? Qtab_line
-                     : Qheader_line));
+                  : (part == ON_TAB_LINE ? Qtab_line
+                     : Qheader_line));
 
           /* Note that mode_line_string takes COL, ROW as pixels and
              converts them to characters.  */
@@ -8115,7 +8117,6 @@ parse_tab_bar_item (Lisp_Object key, Lisp_Object item)
   Lisp_Object filter = Qnil;
   Lisp_Object caption;
   int i;
-  bool have_label = false;
 
   /* Definition looks like `(menu-item CAPTION BINDING PROPS...)'.
      Rule out items that aren't lists, don't start with
@@ -8164,12 +8165,6 @@ parse_tab_bar_item (Lisp_Object key, Lisp_Object item)
     {
       if (menu_separator_name_p (SSDATA (caption)))
         {
-          set_prop_tab_bar (TAB_BAR_ITEM_TYPE, Qt);
-          /* If we use build_desired_tab_bar_string to render the
-             tab bar, the separator is rendered as an image.  */
-          set_prop_tab_bar (TAB_BAR_ITEM_IMAGES,
-                    (menu_item_eval_property
-                     (Vtab_bar_separator_image_expression)));
           set_prop_tab_bar (TAB_BAR_ITEM_ENABLED_P, Qnil);
           set_prop_tab_bar (TAB_BAR_ITEM_SELECTED_P, Qnil);
           set_prop_tab_bar (TAB_BAR_ITEM_CAPTION, Qnil);
@@ -8212,17 +8207,6 @@ parse_tab_bar_item (Lisp_Object key, Lisp_Object item)
       else if (EQ (ikey, QChelp))
         /* `:help HELP-STRING'.  */
         set_prop_tab_bar (TAB_BAR_ITEM_HELP, value);
-      else if (EQ (ikey, QCvert_only))
-        /* `:vert-only t/nil'.  */
-        set_prop_tab_bar (TAB_BAR_ITEM_VERT_ONLY, value);
-      else if (EQ (ikey, QClabel))
-        {
-          const char *bad_label = "!!?GARBLED ITEM?!!";
-          /* `:label LABEL-STRING'.  */
-          set_prop_tab_bar (TAB_BAR_ITEM_LABEL,
-                    STRINGP (value) ? value : build_string (bad_label));
-          have_label = true;
-        }
       else if (EQ (ikey, QCfilter))
         /* ':filter FORM'.  */
         filter = value;
@@ -8236,64 +8220,8 @@ parse_tab_bar_item (Lisp_Object key, Lisp_Object item)
           if (EQ (type, QCtoggle) || EQ (type, QCradio))
             {
               set_prop_tab_bar (TAB_BAR_ITEM_SELECTED_P, selected);
-              set_prop_tab_bar (TAB_BAR_ITEM_TYPE, type);
             }
         }
-      else if (EQ (ikey, QCimage)
-               && (CONSP (value)
-                   || (VECTORP (value) && ASIZE (value) == 4)))
-        /* Value is either a single image specification or a vector
-           of 4 such specifications for the different button states.  */
-        set_prop_tab_bar (TAB_BAR_ITEM_IMAGES, value);
-      else if (EQ (ikey, QCrtl))
-        /* ':rtl STRING' */
-        set_prop_tab_bar (TAB_BAR_ITEM_RTL_IMAGE, value);
-    }
-
-
-  if (!have_label)
-    {
-      /* Try to make one from caption and key.  */
-      Lisp_Object tkey = PROP (TAB_BAR_ITEM_KEY);
-      Lisp_Object tcapt = PROP (TAB_BAR_ITEM_CAPTION);
-      const char *label = SYMBOLP (tkey) ? SSDATA (SYMBOL_NAME (tkey)) : "";
-      const char *capt = STRINGP (tcapt) ? SSDATA (tcapt) : "";
-      ptrdiff_t max_lbl_size =
-        2 * max (0, min (tab_bar_max_label_size, STRING_BYTES_BOUND / 2)) + 1;
-      char *buf = xmalloc (max_lbl_size);
-      Lisp_Object new_lbl;
-      ptrdiff_t caption_len = strnlen (capt, max_lbl_size);
-
-      if (0 < caption_len && caption_len < max_lbl_size)
-        {
-          strcpy (buf, capt);
-          while (caption_len > 0 && buf[caption_len - 1] == '.')
-            caption_len--;
-          buf[caption_len] = '\0';
-          label = capt = buf;
-        }
-
-      ptrdiff_t label_len = strnlen (label, max_lbl_size);
-      if (0 < label_len && label_len < max_lbl_size)
-        {
-          ptrdiff_t j;
-          if (label != buf)
-            strcpy (buf, label);
-
-          for (j = 0; buf[j] != '\0'; ++j)
-            if (buf[j] == '-')
-              buf[j] = ' ';
-          label = buf;
-        }
-      else
-        label = "";
-
-      new_lbl = Fupcase_initials (build_string (label));
-      if (SCHARS (new_lbl) <= tab_bar_max_label_size)
-        set_prop_tab_bar (TAB_BAR_ITEM_LABEL, new_lbl);
-      else
-        set_prop_tab_bar (TAB_BAR_ITEM_LABEL, empty_unibyte_string);
-      xfree (buf);
     }
 
   /* If got a filter apply it on binding.  */
@@ -10711,7 +10639,8 @@ On such systems, Emacs starts a subshell instead of suspending.  */)
   get_tty_size (fileno (CURTTY ()->input), &width, &height);
   if (width != old_width || height != old_height)
     change_frame_size (SELECTED_FRAME (), width,
-                       height - FRAME_MENU_BAR_LINES (SELECTED_FRAME ()) - FRAME_TAB_BAR_LINES (SELECTED_FRAME ()),
+                       height - FRAME_MENU_BAR_LINES (SELECTED_FRAME ())
+                       - FRAME_TAB_BAR_LINES (SELECTED_FRAME ()),
                        0, 0, 0, 0);
 
   run_hook (intern ("suspend-resume-hook"));
diff --git a/src/keymap.c b/src/keymap.c
index c92556ba186..da2786c8449 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -3663,7 +3663,8 @@ be preferred.  */);
   DEFSYM (Qmode_line, "mode-line");
 
   staticpro (&Vmouse_events);
-  Vmouse_events = pure_list (Qmenu_bar, Qtab_bar, Qtool_bar, Qtab_line, Qheader_line, Qmode_line,
+  Vmouse_events = pure_list (Qmenu_bar, Qtab_bar, Qtool_bar,
+                             Qtab_line, Qheader_line, Qmode_line,
                              intern_c_string ("mouse-1"),
                              intern_c_string ("mouse-2"),
                              intern_c_string ("mouse-3"),
diff --git a/src/term.c b/src/term.c
index 6f9ac099907..a189a260788 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2342,7 +2342,8 @@ frame's terminal). */)
              was suspended.  */
           get_tty_size (fileno (t->display_info.tty->input), &width, &height);
           if (width != old_width || height != old_height)
-            change_frame_size (f, width, height - FRAME_MENU_BAR_LINES (f) - FRAME_TAB_BAR_LINES (f),
+            change_frame_size (f, width, height - FRAME_MENU_BAR_LINES (f)
+                               - FRAME_TAB_BAR_LINES (f),
                                0, 0, 0, 0);
           SET_FRAME_VISIBLE (XFRAME (t->display_info.tty->top_frame), 1);
         }
diff --git a/src/w32term.c b/src/w32term.c
index 4d230a2293c..82256db1721 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -5994,7 +5994,8 @@ w32_draw_window_cursor (struct window *w, struct glyph_row *glyph_row,
             = (WINDOW_TO_FRAME_PIXEL_Y (w, w->phys_cursor.y)
                + glyph_row->ascent - w->phys_cursor_ascent);
           w32_system_caret_window = w;
-          w32_system_caret_hdr_height = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
+          w32_system_caret_hdr_height = WINDOW_TAB_LINE_HEIGHT (w)
+            + WINDOW_HEADER_LINE_HEIGHT (w);
           w32_system_caret_mode_height = WINDOW_MODE_LINE_HEIGHT (w);
 
           PostMessage (hwnd, WM_IME_STARTCOMPOSITION, 0, 0);
diff --git a/src/window.c b/src/window.c
index 6749ffde4c1..1d0716eb776 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1321,7 +1321,8 @@ coordinates_in_window (register struct window *w, int x, int y)
                && y < top_y + CURRENT_TAB_LINE_HEIGHT (w)
                && (part = ON_TAB_LINE))
            || (window_wants_header_line (w)
-               && y < top_y + CURRENT_TAB_LINE_HEIGHT (w) + CURRENT_HEADER_LINE_HEIGHT (w)
+               && y < top_y + CURRENT_TAB_LINE_HEIGHT (w)
+                            + CURRENT_HEADER_LINE_HEIGHT (w)
                && (part = ON_HEADER_LINE)))
     {
       /* If it's under/over the scroll bar portion of the mode/header
@@ -5808,8 +5809,9 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror)
       move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
       if (IT_CHARPOS (it) == PT
           && it.current_y >= this_scroll_margin
-          && it.current_y <= last_y - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w)
-          && (NILP (Vscroll_preserve_screen_position)
+          && it.current_y <= last_y - WINDOW_TAB_LINE_HEIGHT (w)
+                                    - WINDOW_HEADER_LINE_HEIGHT (w)
+          && (NILP (Vscroll_preserve_screen_position)
               || EQ (Vscroll_preserve_screen_position, Qt)))
         /* We found PT at a legitimate height.  Leave it alone.  */
         ;
@@ -5824,7 +5826,8 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror)
                  is necessary because we set it.current_y to 0, above.  */
               move_it_to (&it, -1,
                           window_scroll_pixel_based_preserve_x,
-                          goal_y - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w),
+                          goal_y - WINDOW_TAB_LINE_HEIGHT (w)
+                                 - WINDOW_HEADER_LINE_HEIGHT (w),
                           -1, MOVE_TO_Y | MOVE_TO_X);
             }
 
@@ -5860,8 +5863,9 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror)
                   /* We subtract WINDOW_HEADER_LINE_HEIGHT because
                      it.y is relative to the bottom of the header
                      line, see above.  */
-                  (it.last_visible_y - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w)
-                   - partial_line_height (&it) - this_scroll_margin - 1),
+                  (it.last_visible_y - WINDOW_TAB_LINE_HEIGHT (w)
+                                     - WINDOW_HEADER_LINE_HEIGHT (w)
+                   - partial_line_height (&it) - this_scroll_margin - 1),
                   -1,
                   MOVE_TO_POS | MOVE_TO_Y);
 
@@ -5899,13 +5903,15 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror)
       if (it.what == IT_EOB)
         partial_p =
           it.current_y + it.ascent + it.descent
-          > it.last_visible_y - this_scroll_margin - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w);
+          > it.last_visible_y - this_scroll_margin
+          - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w);
       else
         {
           move_it_by_lines (&it, 1);
           partial_p =
             it.current_y
-            > it.last_visible_y - this_scroll_margin - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w);
+            > it.last_visible_y - this_scroll_margin
+              - WINDOW_TAB_LINE_HEIGHT (w) - WINDOW_HEADER_LINE_HEIGHT (w);
         }
 
       if (charpos == PT && !partial_p
diff --git a/src/xdisp.c b/src/xdisp.c
index 0e18c5adbc6..28ef741f074 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1809,7 +1809,7 @@ pos_visible_p (struct window *w, ptrdiff_t charpos, int *x, int *y,
           *rowh = max (0, (min (it2.current_y + it2.max_ascent + it2.max_descent,
                                 it.last_visible_y)
                            - max (max (it2.current_y,
-                                       WINDOW_TAB_LINE_HEIGHT (w)),
+                                       WINDOW_TAB_LINE_HEIGHT (w)),
                                   WINDOW_HEADER_LINE_HEIGHT (w))));
           *vpos = it2.vpos;
           if (it2.bidi_it.paragraph_dir == R2L)
@@ -2532,8 +2532,8 @@ remember_mouse_glyph (struct frame *f, int gx, int gy, NativeRectangle *rect)
       gr = (part == ON_TAB_LINE
             ? MATRIX_TAB_LINE_ROW (w->current_matrix)
             : (part == ON_HEADER_LINE
-               ? MATRIX_HEADER_LINE_ROW (w->current_matrix)
-               : MATRIX_MODE_LINE_ROW (w->current_matrix)));
+               ? MATRIX_HEADER_LINE_ROW (w->current_matrix)
+               : MATRIX_MODE_LINE_ROW (w->current_matrix)));
       gy = gr->y;
       area = TEXT_AREA;
       goto text_glyph_row_found;
@@ -2579,7 +2579,8 @@ remember_mouse_glyph (struct frame *f, int gx, int gy, NativeRectangle *rect)
               gx += (x / width) * width;
             }
 
-          if (part != ON_MODE_LINE && part != ON_HEADER_LINE && part != ON_TAB_LINE)
+          if (part != ON_MODE_LINE && part != ON_HEADER_LINE
+              && part != ON_TAB_LINE)
             {
               gx += window_box_left_offset (w, area);
               /* Don't expand over the modeline to make sure the vertical
@@ -2594,7 +2595,8 @@ remember_mouse_glyph (struct frame *f, int gx, int gy, NativeRectangle *rect)
           gx = (x / width) * width;
           y -= gy;
           gy += (y / height) * height;
-          if (part != ON_MODE_LINE && part != ON_HEADER_LINE && part != ON_TAB_LINE)
+          if (part != ON_MODE_LINE && part != ON_HEADER_LINE
+              && part != ON_TAB_LINE)
             /* See comment above.  */
             height = min (height,
                           max (0, WINDOW_BOX_HEIGHT_NO_MODE_LINE (w) - gy));
@@ -12688,7 +12690,9 @@ display_tab_bar (struct window *w)
 
 #if defined (USE_X_TOOLKIT) || defined (USE_GTK)
   eassert (!FRAME_WINDOW_P (f));
-  init_iterator (&it, w, -1, -1, f->desired_matrix->rows + (FRAME_MENU_BAR_LINES (f) > 0 ? 1 : 0), TAB_BAR_FACE_ID);
+  init_iterator (&it, w, -1, -1, f->desired_matrix->rows
+                 + (FRAME_MENU_BAR_LINES (f) > 0 ? 1 : 0),
+                 TAB_BAR_FACE_ID);
   it.first_visible_x = 0;
   it.last_visible_x = FRAME_PIXEL_WIDTH (f);
 #elif defined (HAVE_X_WINDOWS) /* X without toolkit.  */
@@ -12708,7 +12712,8 @@ display_tab_bar (struct window *w)
     {
       /* This is a TTY frame, i.e. character hpos/vpos are used as
          pixel x/y.  */
-      init_iterator (&it, w, -1, -1, f->desired_matrix->rows + (FRAME_MENU_BAR_LINES (f) > 0 ? 1 : 0),
+      init_iterator (&it, w, -1, -1, f->desired_matrix->rows
+                     + (FRAME_MENU_BAR_LINES (f) > 0 ? 1 : 0),
                      TAB_BAR_FACE_ID);
       it.first_visible_x = 0;
       it.last_visible_x = FRAME_COLS (f);
@@ -17164,7 +17169,8 @@ compute_window_start_on_continuation_line (struct window *w)
 
       /* Find the start of the continued line.  This should be fast
          because find_newline is fast (newline cache).  */
-      row = w->desired_matrix->rows + window_wants_tab_line (w) + window_wants_header_line (w);
+      row = w->desired_matrix->rows + window_wants_tab_line (w)
+                                    + window_wants_header_line (w);
       init_iterator (&it, w, CHARPOS (start_pos), BYTEPOS (start_pos),
                      row, DEFAULT_FACE_ID);
       reseat_at_previous_visible_line_start (&it);
@@ -18677,7 +18683,7 @@ redisplay_window (Lisp_Object window, bool just_this_one_p)
       /* This means that the window has a mode line.  */
       && (window_wants_mode_line (w)
           || window_wants_header_line (w)
-          || window_wants_tab_line (w)))
+          || window_wants_tab_line (w)))
     {
 
       display_mode_lines (w);
@@ -20822,7 +20828,8 @@ do nothing.  */)
   EMACS_INT vpos;
 
   if (NILP (row))
-    vpos = WINDOWP (sf->tab_bar_window) ? 0 : FRAME_MENU_BAR_LINES (sf) > 0 ? 1 : 0;
+    vpos = WINDOWP (sf->tab_bar_window) ? 0 :
+      FRAME_MENU_BAR_LINES (sf) > 0 ? 1 : 0;
   else
     {
       CHECK_FIXNUM (row);
@@ -32350,8 +32357,8 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
       row = (area == ON_MODE_LINE
              ? MATRIX_MODE_LINE_ROW (w->current_matrix)
              : (area == ON_TAB_LINE
-                ? MATRIX_TAB_LINE_ROW (w->current_matrix)
-                : MATRIX_HEADER_LINE_ROW (w->current_matrix)));
+                ? MATRIX_TAB_LINE_ROW (w->current_matrix)
+                : MATRIX_HEADER_LINE_ROW (w->current_matrix)));
 
       /* Find the glyph under the mouse pointer.  */
       if (row->mode_line_p && row->enabled_p)
@@ -32466,7 +32473,8 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
 
               /* Change the mouse pointer according to what is under X/Y.  */
               if (NILP (pointer)
-                  && (area == ON_MODE_LINE || area == ON_HEADER_LINE || area == ON_TAB_LINE))
+                  && (area == ON_MODE_LINE || area == ON_HEADER_LINE
+                      || area == ON_TAB_LINE))
                 {
                   Lisp_Object map;
 
@@ -32492,7 +32500,8 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
     {
       mouse_face = Fget_text_property (pos, Qmouse_face, string);
       if (!NILP (Vmouse_highlight) && !NILP (mouse_face)
-          && ((area == ON_MODE_LINE) || (area == ON_HEADER_LINE) || (area == ON_TAB_LINE))
+          && ((area == ON_MODE_LINE) || (area == ON_HEADER_LINE)
+              || (area == ON_TAB_LINE))
           && glyph)
         {
           Lisp_Object b, e;
@@ -32564,10 +32573,10 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
           vpos = (area == ON_MODE_LINE
                   ? (w->current_matrix)->nrows - 1
                   : (area == ON_TAB_LINE
-                     ? 0
-                     : (w->current_matrix->tab_line_p
-                        ? 1
-                        : 0)));
+                     ? 0
+                     : (w->current_matrix->tab_line_p
+                        ? 1
+                        : 0)));
 
           /* If GLYPH's position is included in the region that is
              already drawn in mouse face, we have nothing to do.  */
@@ -32623,7 +32632,8 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
 
   /* If mouse-face doesn't need to be shown, clear any existing
      mouse-face.  */
-  if ((area == ON_MODE_LINE || area == ON_HEADER_LINE || area == ON_TAB_LINE) && !mouse_face_shown)
+  if ((area == ON_MODE_LINE || area == ON_HEADER_LINE
+       || area == ON_TAB_LINE) && !mouse_face_shown)
     clear_mouse_face (hlinfo);
 
   define_frame_cursor1 (f, cursor, pointer);
@@ -34372,10 +34382,6 @@ vertical margin.  */);
     doc: /* Relief thickness of tab-bar buttons.  */);
   tab_bar_button_relief = DEFAULT_TAB_BAR_BUTTON_RELIEF;
 
-  DEFVAR_INT ("tab-bar-max-label-size", tab_bar_max_label_size,
-    doc: /* Maximum number of characters a label can have to be shown.  */);
-  tab_bar_max_label_size = DEFAULT_TAB_BAR_LABEL_SIZE;
-
   DEFVAR_LISP ("tool-bar-border", Vtool_bar_border,
     doc: /* Border below tool-bar in pixels.
 If an integer, use it as the height of the border.
diff --git a/src/xfaces.c b/src/xfaces.c
index ccf33795071..4e404dc49a9 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -6585,8 +6585,8 @@ syms_of_xfaces (void)
   DEFSYM (Qtool_bar, "tool-bar");
   DEFSYM (Qtab_bar, "tab-bar");
   DEFSYM (Qfringe, "fringe");
-  DEFSYM (Qheader_line, "header-line");
   DEFSYM (Qtab_line, "tab-line");
+  DEFSYM (Qheader_line, "header-line");
   DEFSYM (Qscroll_bar, "scroll-bar");
   DEFSYM (Qmenu, "menu");
   DEFSYM (Qcursor, "cursor");
diff --git a/src/xfns.c b/src/xfns.c
index be869fdd244..20e63a26501 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -2820,7 +2820,6 @@ xic_set_statusarea (struct frame *f)
   area.x = FRAME_PIXEL_WIDTH (f) - area.width - FRAME_INTERNAL_BORDER_WIDTH (f);
   area.y = (FRAME_PIXEL_HEIGHT (f) - area.height
             - FRAME_MENUBAR_HEIGHT (f)
-            - FRAME_TABBAR_TOP_HEIGHT (f)
             - FRAME_TOOLBAR_TOP_HEIGHT (f)
             - FRAME_INTERNAL_BORDER_WIDTH (f));
   XFree (needed);
diff --git a/src/xterm.c b/src/xterm.c
index 428d970206e..0b9cbdebd6b 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -3223,8 +3223,8 @@ x_draw_image_relief (struct glyph_string *s)
       thick = (tab_bar_button_relief < 0
                ? DEFAULT_TAB_BAR_BUTTON_RELIEF
                : (tool_bar_button_relief < 0
-                  ? DEFAULT_TOOL_BAR_BUTTON_RELIEF
-                  : min (tool_bar_button_relief, 1000000)));
+                  ? DEFAULT_TOOL_BAR_BUTTON_RELIEF
+                  : min (tool_bar_button_relief, 1000000)));
       raised_p = s->hl == DRAW_IMAGE_RAISED;
     }
   else
@@ -10222,7 +10222,7 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
                              false, Qfont);
 #ifndef USE_X_TOOLKIT
           if ((FRAME_MENU_BAR_HEIGHT (f) != old_menu_bar_height
-               || FRAME_TAB_BAR_HEIGHT (f) != old_tab_bar_height)
+               || FRAME_TAB_BAR_HEIGHT (f) != old_tab_bar_height)
               && !f->after_make_frame
               && (EQ (frame_inhibit_implied_resize, Qt)
                   || (CONSP (frame_inhibit_implied_resize)
@@ -10232,7 +10232,8 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
             /* If the menu/tab bar height changes, try to keep text height
                constant.  */
             adjust_frame_size
-              (f, -1, FRAME_TEXT_HEIGHT (f) + FRAME_MENU_BAR_HEIGHT (f) + FRAME_TAB_BAR_HEIGHT (f)
+              (f, -1, FRAME_TEXT_HEIGHT (f) + FRAME_MENU_BAR_HEIGHT (f)
+               + FRAME_TAB_BAR_HEIGHT (f)
                - old_menu_bar_height - old_tab_bar_height, 1, false, Qfont);
 #endif /* USE_X_TOOLKIT  */
         }
@@ -11168,7 +11169,7 @@ x_check_fullscreen (struct frame *f)
         case FULLSCREEN_WIDTH:
           lval = Qfullwidth;
           width = x_display_pixel_width (dpyinfo);
-          height = height + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f);
+          height = height + FRAME_MENUBAR_HEIGHT (f);
           break;
         case FULLSCREEN_HEIGHT:
           lval = Qfullheight;
@@ -11190,7 +11191,7 @@ x_check_fullscreen (struct frame *f)
         x_wait_for_event (f, ConfigureNotify);
       else
         {
-          change_frame_size (f, width, height - FRAME_MENUBAR_HEIGHT (f) - FRAME_TABBAR_HEIGHT (f),
+          change_frame_size (f, width, height - FRAME_MENUBAR_HEIGHT (f),
                              false, true, false, true);
           x_sync (f);
         }
@@ -11366,10 +11367,10 @@ x_set_window_size_1 (struct frame *f, bool change_gravity,
     {
       frame_size_history_add
         (f, Qx_set_window_size_1, width, height,
-         list2i (old_height, pixelheight + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f)));
+         list2i (old_height, pixelheight + FRAME_MENUBAR_HEIGHT (f)));
 
       XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
-                     old_width, pixelheight + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f));
+                     old_width, pixelheight + FRAME_MENUBAR_HEIGHT (f));
     }
   else if (EQ (fullscreen, Qfullheight) && height == FRAME_TEXT_HEIGHT (f))
     {
@@ -11385,12 +11386,13 @@ x_set_window_size_1 (struct frame *f, bool change_gravity,
     {
       frame_size_history_add
         (f, Qx_set_window_size_3, width, height,
-         list3i (pixelwidth + FRAME_TOOLBAR_WIDTH (f) + FRAME_TABBAR_WIDTH (f),
-                 (pixelheight + FRAME_TOOLBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f) + FRAME_MENUBAR_HEIGHT (f)),
-                 FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f)));
+         list3i (pixelwidth + FRAME_TOOLBAR_WIDTH (f),
+                 (pixelheight + FRAME_TOOLBAR_HEIGHT (f)
+                  + FRAME_MENUBAR_HEIGHT (f)),
+                 FRAME_MENUBAR_HEIGHT (f)));
 
       XResizeWindow (FRAME_X_DISPLAY (f), FRAME_OUTER_WINDOW (f),
-                     pixelwidth, pixelheight + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f));
+                     pixelwidth, pixelheight + FRAME_MENUBAR_HEIGHT (f));
       fullscreen = Qnil;
     }
 
@@ -11467,7 +11469,7 @@ x_set_window_size (struct frame *f, bool change_gravity,
 #ifdef USE_X_TOOLKIT
       /* The menu bar is not part of text lines.  The tool bar
          is however.  */
-      pixelh -= FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f);
+      pixelh -= FRAME_MENUBAR_HEIGHT (f);
 #endif
       text_width = FRAME_PIXEL_TO_TEXT_WIDTH (f, FRAME_PIXEL_WIDTH (f));
       text_height = FRAME_PIXEL_TO_TEXT_HEIGHT (f, pixelh);
@@ -12263,7 +12265,7 @@ x_wm_set_size_hint (struct frame *f, long flags, bool user_position)
 
     size_hints.flags |= PBaseSize;
     size_hints.base_width = base_width;
-    size_hints.base_height = base_height + FRAME_MENUBAR_HEIGHT (f) + FRAME_TABBAR_HEIGHT (f);
+    size_hints.base_height = base_height + FRAME_MENUBAR_HEIGHT (f);
     size_hints.min_width  = base_width;
     size_hints.min_height = base_height;
   }
diff --git a/src/xterm.h b/src/xterm.h
index 5b4d47d3b62..69af552e078 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -505,16 +505,6 @@ struct x_output
   int menubar_height;
 #endif
 
-  /* Height of tab bar widget, in pixels.  top_height is used if tab bar
-     at top, bottom_height if tab bar is at the bottom.
-     Zero if not using an external tab bar or if tab bar is vertical.  */
-  int tabbar_top_height, tabbar_bottom_height;
-
-  /* Width of tab bar widget, in pixels.  left_width is used if tab bar
-     at left, right_width if tab bar is at the right.
-     Zero if not using an external tab bar or if tab bar is horizontal.  */
-  int tabbar_left_width, tabbar_right_width;
-
   /* Height of tool bar widget, in pixels.  top_height is used if tool bar
      at top, bottom_height if tool bar is at the bottom.
      Zero if not using an external tool bar or if tool bar is vertical.  */
@@ -582,11 +572,6 @@ struct x_output
   GtkWidget *hbox_widget;
   /* The menubar in this frame.  */
   GtkWidget *menubar_widget;
-  /* The tab bar in this frame  */
-  GtkWidget *tabbar_widget;
-  /* True if tab bar is packed into the hbox widget (i.e. vertical).  */
-  bool_bf tabbar_in_hbox : 1;
-  bool_bf tabbar_is_packed : 1;
   /* The tool bar in this frame  */
   GtkWidget *toolbar_widget;
   /* True if tool bar is packed into the hbox widget (i.e. vertical).  */
@@ -830,15 +815,6 @@ extern void x_mark_frame_dirty (struct frame *f);
 
 #define FRAME_FONT(f) ((f)->output_data.x->font)
 #define FRAME_FONTSET(f) ((f)->output_data.x->fontset)
-#define FRAME_TABBAR_TOP_HEIGHT(f) ((f)->output_data.x->tabbar_top_height)
-#define FRAME_TABBAR_BOTTOM_HEIGHT(f) \
-  ((f)->output_data.x->tabbar_bottom_height)
-#define FRAME_TABBAR_HEIGHT(f) \
-  (FRAME_TABBAR_TOP_HEIGHT (f) + FRAME_TABBAR_BOTTOM_HEIGHT (f))
-#define FRAME_TABBAR_LEFT_WIDTH(f) ((f)->output_data.x->tabbar_left_width)
-#define FRAME_TABBAR_RIGHT_WIDTH(f) ((f)->output_data.x->tabbar_right_width)
-#define FRAME_TABBAR_WIDTH(f) \
-  (FRAME_TABBAR_LEFT_WIDTH (f) + FRAME_TABBAR_RIGHT_WIDTH (f))
 #define FRAME_TOOLBAR_TOP_HEIGHT(f) ((f)->output_data.x->toolbar_top_height)
 #define FRAME_TOOLBAR_BOTTOM_HEIGHT(f) \
   ((f)->output_data.x->toolbar_bottom_height)