* src/xdisp.c (tab-bar-truncate): New variable (bug#78953).

(tab_bar_height): Use it.

2 files changed, 18 insertions, 1 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 3889cb0e8f1..a81d1105443 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -398,6 +398,11 @@ normally shown in the echo area or via tooltips.  See the variable's
 docstring for arguments passed to a help-text function.
 
 ---
+*** New variable 'tab-bar-truncate'.
+When non-nil, it truncates the tab bar, and therefore prevents
+wrapping and resizing the tab bar to more than one line.
+
+---
 *** New command 'tab-line-move-tab-forward' ('C-x M-<right>').
 Together with the new command 'tab-line-move-tab-backward'
 ('C-x M-<left>'), it can be used to move the current tab
diff --git a/src/xdisp.c b/src/xdisp.c
index 15a88f0868a..992d162f2e3 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14739,11 +14739,19 @@ tab_bar_height (struct frame *f, int *n_rows, bool pixelwise)
   it.paragraph_embedding = L2R;
 
   clear_glyph_row (temp_row);
-  while (!ITERATOR_AT_END_P (&it))
+  if (tab_bar_truncate)
     {
       it.glyph_row = temp_row;
       display_tab_bar_line (&it, -1);
     }
+  else
+    {
+      while (!ITERATOR_AT_END_P (&it))
+        {
+          it.glyph_row = temp_row;
+          display_tab_bar_line (&it, -1);
+        }
+    }
   clear_glyph_row (temp_row);
 
   /* f->n_tab_bar_rows == 0 means "unknown"; -1 means no tab-bar.  */
@@ -38209,6 +38217,10 @@ window, nil if it's okay to leave the cursor partially-visible.  */);
   DEFSYM (Qmake_window_start_visible, "make-window-start-visible");
   Fmake_variable_buffer_local (Qmake_window_start_visible);
 
+  DEFVAR_BOOL ("tab-bar-truncate", tab_bar_truncate,
+    doc: /* Non-nil means truncate tab-bar and show only one line.  */);
+  tab_bar_truncate = false;
+
   DEFSYM (Qclose_tab, "close-tab");
   DEFVAR_LISP ("tab-bar-border", Vtab_bar_border,
     doc: /* Border below tab-bar in pixels.