master 8a4bb6b: Fix a problem with x_set_tab_bar_lines (Bug#46827)

[Martin Rudalics]

branch: master
commit 8a4bb6b0560ef3f4890789a574488f7cf69ee237
Author: Martin Rudalics <rudalics@gmx.at>
Commit: Martin Rudalics <rudalics@gmx.at>

    Fix a problem with x_set_tab_bar_lines (Bug#46827)
    
    * src/xfns.c (x_set_tab_bar_lines): Call
    x_change_tab_bar_height only if the number of tab bar lines
    changed from or to zero (Bug#46827).
    * src/xterm.c (x_make_frame_visible): Make frame_size_history
    update less noisy by doing it only if the frame wasn't visible
    before.
---
 src/xfns.c  |  9 ++++++---
 src/xterm.c | 12 +++++++-----
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/xfns.c b/src/xfns.c
index 2c95065..782e0a4 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -1608,13 +1608,15 @@ x_set_menu_bar_lines (struct frame *f, Lisp_Object 
value, Lisp_Object oldval)
 
 /* Set the number of lines used for the tab bar of frame F to VALUE.
    VALUE not an integer, or < 0 means set the lines to zero.  OLDVAL
-   is the old number of tab bar lines.  This function changes the
+   is the old number of tab bar lines.  This function may change the
    height of all windows on frame F to match the new tab bar height.
-   The frame's height doesn't change.  */
+   The frame's height may change if frame_inhibit_implied_resize was
+   set accordingly.  */
 
 static void
 x_set_tab_bar_lines (struct frame *f, Lisp_Object value, Lisp_Object oldval)
 {
+  int olines = FRAME_TAB_BAR_LINES (f);
   int nlines;
 
   /* Treat tab bars like menu bars.  */
@@ -1627,7 +1629,8 @@ x_set_tab_bar_lines (struct frame *f, Lisp_Object value, 
Lisp_Object oldval)
   else
     nlines = 0;
 
-  x_change_tab_bar_height (f, nlines * FRAME_LINE_HEIGHT (f));
+  if (nlines != olines && (olines == 0 || nlines == 0))
+    x_change_tab_bar_height (f, nlines * FRAME_LINE_HEIGHT (f));
 }
 
 
diff --git a/src/xterm.c b/src/xterm.c
index 189e3a4..88a393c 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -11823,12 +11823,14 @@ x_make_frame_visible (struct frame *f)
     poll_suppress_count = old_poll_suppress_count;
 #endif
 
-    if (CONSP (frame_size_history))
-      frame_size_history_plain
-       (f, build_string ("x_make_frame_visible"));
+    if (!FRAME_VISIBLE_P (f))
+      {
+       if (CONSP (frame_size_history))
+         frame_size_history_plain
+           (f, build_string ("x_make_frame_visible"));
 
-    if (! FRAME_VISIBLE_P (f))
-      x_wait_for_event (f, MapNotify);
+       x_wait_for_event (f, MapNotify);
+      }
   }
 }