3 files changed, 21 insertions, 4 deletions

diff --git a/etc/NEWS b/etc/NEWS
index d06f0a59528..d6a7231474e 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -2134,6 +2134,8 @@ disabled: by default, they enable tab-bar-mode in that case.
 The X resource "tabBar", class "TabBar" enables the tab bar
 when its value is "on", "yes" or "1".
 
+The variable 'tab-bar-position' specifies where to show the tab bar.
+
 Read the new Info node "(emacs) Tab Bars" for full description
 of all related features.
 
diff --git a/lisp/cus-start.el b/lisp/cus-start.el
index 89a96a9f51c..d1278192ef7 100644
--- a/lisp/cus-start.el
+++ b/lisp/cus-start.el
@@ -591,6 +591,12 @@ since it could result in memory overflow and make Emacs crash."
                       (const :tag "Text-image-horiz" :value text-image-horiz)
                       (const :tag "System default" :value nil)) "24.1")
              (tool-bar-max-label-size frames integer "24.1")
+             (tab-bar-position tab-bar boolean "27.1"
+                               :set (lambda (sym val)
+                                      (set-default sym val)
+                                      ;; Redraw the bars:
+                                      (tab-bar-mode -1)
+                                      (tab-bar-mode 1)))
              (auto-hscroll-mode scrolling
                                 (choice
                                  (const :tag "Don't scroll automatically"
diff --git a/src/dispnew.c b/src/dispnew.c
index 4dd5ee2a1e0..4cdc76f5bcf 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -2166,8 +2166,10 @@ adjust_frame_glyphs_for_window_redisplay (struct frame *f)
 
     w->pixel_left = 0;
     w->left_col = 0;
-    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f);
-    w->top_line = FRAME_MENU_BAR_LINES (f);
+    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f)
+      + (!NILP (Vtab_bar_position) ? FRAME_TOOL_BAR_HEIGHT (f) : 0);
+    w->top_line = FRAME_MENU_BAR_LINES (f)
+      + (!NILP (Vtab_bar_position) ? FRAME_TOOL_BAR_LINES (f) : 0);
     w->total_cols = FRAME_TOTAL_COLS (f);
     w->pixel_width = (FRAME_PIXEL_WIDTH (f)
                        - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));
@@ -2196,8 +2198,10 @@ adjust_frame_glyphs_for_window_redisplay (struct frame *f)
 
     w->pixel_left = 0;
     w->left_col = 0;
-    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f) + FRAME_TAB_BAR_HEIGHT (f);
-    w->top_line = FRAME_MENU_BAR_LINES (f) + FRAME_TAB_BAR_LINES (f);
+    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f)
+      + (NILP (Vtab_bar_position) ? FRAME_TAB_BAR_HEIGHT (f) : 0);
+    w->top_line = FRAME_MENU_BAR_LINES (f)
+      + (NILP (Vtab_bar_position) ? FRAME_TAB_BAR_LINES (f) : 0);
     w->total_cols = FRAME_TOTAL_COLS (f);
     w->pixel_width = (FRAME_PIXEL_WIDTH (f)
                        - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));
@@ -6569,6 +6573,11 @@ See `buffer-display-table' for more information.  */);
      beginning of the next redisplay).  */
   redisplay_dont_pause = true;
 
+  DEFVAR_LISP ("tab-bar-position", Vtab_bar_position,
+               doc: /* Specify on which side from the tool bar the tab bar shall be.
+Possible values are `t' (below the tool bar), `nil' (above the tool bar).
+This option affects only builds where the tool bar is not external.  */);
+
   pdumper_do_now_and_after_load (syms_of_display_for_pdumper);
 }