Subject: Re: bug#43973: 28.0.50; [NS] Two crashes on macOS

From: Alan Third <[email-masked]>
Date: Sat, 2 Jan 2021 18:25:36 +0000

On Thu, Oct 15, 2020 at 12:33:44AM +0300, Andrii Kolomoiets wrote:
> Alan Third <[email-masked]> writes:
> 
> >> The frame must be small enough to not all the toolbar buttons fits the
> >> toolbar:
> >> 
> >> (setq test-frame (make-frame `((parent-frame . ,(selected-frame))
> >> 			                   (width . 41))))
> >> 
> >> The last button (isearch) is replaced by ">>".
> >
> > Funnily enough that ">>" is what I was looking at. I guess it's a
> > toolkit image and not something we provide with Emacs...?
> >
> >> There are no crash if '(width . 42)'.
> >
> > Can you try this:

Can you please try the attached patch. It looks like NSToolbarItem
makes a copy of the image, but EmacsImage is not set up to create
copies of itself correctly.
-- 
Alan Third
>From d111484d44744e3f68775a47b7f15ddf0d9b38c0 Mon Sep 17 00:00:00 2001
From: Alan Third <[email-masked]>
Date: Sat, 2 Jan 2021 18:19:39 +0000
Subject: [PATCH] Fix crash in NS toolbar image releasing (bug#43973)

The toolbar fails to make a proper copy of EmacsImage objects, so
releasing the copy incorrectly released instance variables from the
original objects.

* src/nsimage.m ([EmacsImage copyWithZone:]): New function to enable
correct copying of EmacsImage.
---
 src/nsimage.m | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/nsimage.m b/src/nsimage.m
index f0014b50b9..fa81a41a51 100644
--- a/src/nsimage.m
+++ b/src/nsimage.m
@@ -293,6 +293,18 @@ - (void)dealloc
 }

+- (id)copyWithZone:(NSZone *)zone
+{
+  EmacsImage *copy = [super copyWithZone:zone];
+
+  copy->stippleMask = [stippleMask copyWithZone:zone];
+  copy->bmRep = [bmRep copyWithZone:zone];
+  copy->transform = [transform copyWithZone:zone];
+
+  return copy;
+}
+
+
 /* Create image from monochrome bitmap. If both FG and BG are 0
    (black), set the background to white and make it transparent.  */
 - (instancetype)initFromXBM: (unsigned char *)bits width: (int)w height: (int)h
-- 
2.29.2