Subject: Re: bug#48157: Emacs-28 on Mac: corrupted GUI when setting default-frame-alist

From: martin rudalics <[email-masked]>
Date: Mon, 3 May 2021 09:56:45 +0200

> I retried a couple of minutes ago and it continues to startup weirdly on my
 > MacBook Air

Did you try Alan's latest fixes (I attach them here)?

martin
>>From c4048b3cd6841a7f2ccdfb3f6c880c9ee176390a Mon Sep 17 00:00:00 2001
From: Alan Third <[email-masked]>
Date: Sun, 2 May 2021 22:38:13 +0100
Subject: [PATCH] Fix incorrect resizing behaviour on macOS (bug#48157,
 bug#48162)

* src/nsterm.m ([EmacsView viewDidResize:]): The drawing buffer can be
resized independently of Emacs's idea of the frame size.

Co-authored-by: martin rudalics <[email-masked]>
---
 src/nsterm.m | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/src/nsterm.m b/src/nsterm.m
index 6e7ab1266b..bb20886ab1 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -7303,16 +7303,34 @@ - (void)viewDidResize:(NSNotification *)notification

   NSTRACE ("[EmacsView viewDidResize]");

+#ifdef NS_DRAW_TO_BUFFER
+  /* If the buffer size doesn't match the view's backing size, destroy
+     the buffer and let it be recreated at the correct size later.  */
+  if ([self wantsUpdateLayer] && surface)
+    {
+      NSRect surfaceRect = {{0, 0}, [surface getSize]};
+      NSRect frameRect = [[self window] convertRectToBacking:frame];
+
+      if (!NSEqualRects (frameRect, surfaceRect))
+        {
+          [surface release];
+          surface = nil;
+
+          [self setNeedsDisplay:YES];
+        }
+    }
+#endif
+
   neww = (int)NSWidth (frame);
   newh = (int)NSHeight (frame);
   oldw = FRAME_PIXEL_WIDTH (emacsframe);
   oldh = FRAME_PIXEL_HEIGHT (emacsframe);

   /* Don't want to do anything when the view size hasn't changed. */
-  if ((oldh == newh && oldw == neww)
-      || (emacsframe->new_size_p
-          && newh == emacsframe->new_height
-          && neww == emacsframe->new_width))
+  if (emacsframe->new_size_p
+      ? (newh == emacsframe->new_height
+         && neww == emacsframe->new_width)
+      : (oldh == newh && oldw == neww))
     {
       NSTRACE_MSG ("No change");
       return;
@@ -7321,16 +7339,6 @@ - (void)viewDidResize:(NSNotification *)notification
   NSTRACE_SIZE ("New size", NSMakeSize (neww, newh));
   NSTRACE_SIZE ("Original size", NSMakeSize (oldw, oldh));

-#ifdef NS_DRAW_TO_BUFFER
-  if ([self wantsUpdateLayer])
-    {
-      [surface release];
-      surface = nil;
-
-      [self setNeedsDisplay:YES];
-    }
-#endif
-
   change_frame_size (emacsframe, neww, newh, false, YES, false);

   SET_FRAME_GARBAGED (emacsframe);
--
2.30.2