[Emacs-diffs] master fb10834: Avoid that unwind_format_mode_line messes up buffer points (Bug#32777)

[Martin Rudalics]

branch: master
commit fb10834a602416f8422131d5ce9dabcc28e57be4
Author: Martin Rudalics <address@hidden>
Commit: Martin Rudalics <address@hidden>

    Avoid that unwind_format_mode_line messes up buffer points (Bug#32777)
    
    * src/xdisp.c (format_mode_line_unwind_data): Before
    temporarily selecting a window on another frame, separately save
    the point of that window's buffer too.
    (unwind_format_mode_line): After undoing the temporary
    selection of a window on another frame, separately restore the
    buffer point of that window.  This is needed since the
    operation that deselects that window will have stored back the
    point of that window into its buffer's point which is wrong
    since that window was never "officially" selected (Bug#32777).
---
 src/xdisp.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/xdisp.c b/src/xdisp.c
index 4201bdc..65a61a0 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -11850,7 +11850,7 @@ format_mode_line_unwind_data (struct frame 
*target_frame,
   Vmode_line_unwind_vector = Qnil;
 
   if (NILP (vector))
-    vector = make_nil_vector (10);
+    vector = make_nil_vector (12);
 
   ASET (vector, 0, make_fixnum (mode_line_target));
   ASET (vector, 1, make_fixnum (MODE_LINE_NOPROP_LEN (0)));
@@ -11867,12 +11867,24 @@ format_mode_line_unwind_data (struct frame 
*target_frame,
   ASET (vector, 7, owin);
   if (target_frame)
     {
+      Lisp_Object buffer = XWINDOW (target_frame->selected_window)->contents;
+      struct buffer *b = XBUFFER (buffer);
+      struct buffer *cb = current_buffer;
+
       /* Similarly to `with-selected-window', if the operation selects
         a window on another frame, we must restore that frame's
         selected window, and (for a tty) the top-frame.  */
       ASET (vector, 8, target_frame->selected_window);
       if (FRAME_TERMCAP_P (target_frame))
        ASET (vector, 9, FRAME_TTY (target_frame)->top_frame);
+
+      /* If we select a window on another frame, make sure that that
+        selection does not leave its buffer's point modified when
+        unwinding (Bug#32777).  */
+      ASET (vector, 10, buffer);
+      current_buffer = b;
+      ASET (vector, 11, build_marker (current_buffer, PT, PT_BYTE));
+      current_buffer = cb;
     }
 
   return vector;
@@ -11912,6 +11924,24 @@ unwind_format_mode_line (Lisp_Object vector)
        }
 
       Fselect_window (old_window, Qt);
+
+      /* Restore point of target_frame_window's buffer (Bug#32777).
+        But do this only after old_window has been reselected to
+        avoid that the window point of target_frame_window moves.  */
+      if (!NILP (target_frame_window))
+       {
+         Lisp_Object buffer = AREF (vector, 10);
+
+         if (BUFFER_LIVE_P (XBUFFER (buffer)))
+           {
+             struct buffer *cb = current_buffer;
+
+             current_buffer = XBUFFER (buffer);
+             set_point_from_marker (AREF (vector, 11));
+             ASET (vector, 11, Qnil);
+             current_buffer = cb;
+           }
+       }
     }
 
   if (!NILP (AREF (vector, 6)))