Changes installed in d22d7d6be8c

[Po Lu]

I see the following code in nsterm.m:

d22d7d6be8c (Alan Third            2021-09-27  7934)   NSRect dstRect = 
NSMakeRect (dest.x, dest.y, NSWidth (srcRect),
d22d7d6be8c (Alan Third            2021-09-27  7935)                            
    NSHeight (srcRect));
d22d7d6be8c (Alan Third            2021-09-27  7936)   NSRect frame = [self 
frame];
d22d7d6be8c (Alan Third            2021-09-27  7937) 
d22d7d6be8c (Alan Third            2021-09-27  7938)   /* TODO: This check is 
an attempt to debug a rare graphical glitch
d22d7d6be8c (Alan Third            2021-09-27  7939)      on macOS and should 
be removed before the Emacs 28 release.  */
d22d7d6be8c (Alan Third            2021-09-27  7940)   if (!NSContainsRect 
(frame, srcRect)
d22d7d6be8c (Alan Third            2021-09-27  7941)       || !NSContainsRect 
(frame, dstRect))
d22d7d6be8c (Alan Third            2021-09-27  7942)     {
d22d7d6be8c (Alan Third            2021-09-27  7943)       NSLog (@"[EmacsView 
copyRect:to:] Attempting to copy to or "
d22d7d6be8c (Alan Third            2021-09-27  7944)              "from an area 
outside the graphics buffer.");
d22d7d6be8c (Alan Third            2021-09-27  7945)       NSLog (@"  Frame: 
(%f, %f) %f×%f",
d22d7d6be8c (Alan Third            2021-09-27  7946)              NSMinX 
(frame), NSMinY (frame),
d22d7d6be8c (Alan Third            2021-09-27  7947)              NSWidth 
(frame), NSHeight (frame));
d22d7d6be8c (Alan Third            2021-09-27  7948)       NSLog (@"  Source: 
(%f, %f) %f×%f",
d22d7d6be8c (Alan Third            2021-09-27  7949)              NSMinX 
(srcRect), NSMinY (srcRect),
d22d7d6be8c (Alan Third            2021-09-27  7950)              NSWidth 
(srcRect), NSHeight (srcRect));
d22d7d6be8c (Alan Third            2021-09-27  7951)       NSLog (@"  
Destination: (%f, %f) %f×%f",
d22d7d6be8c (Alan Third            2021-09-27  7952)              NSMinX 
(dstRect), NSMinY (dstRect),
d22d7d6be8c (Alan Third            2021-09-27  7953)              NSWidth 
(dstRect), NSHeight (dstRect));
d22d7d6be8c (Alan Third            2021-09-27  7954)     }

Could someone explain exactly how the graphical glitch here manifests?

It's also getting close to the Emacs 28 release, so maybe this should be
removed there.

Thanks in advance.