Subject: bug#72692: Emacs 31.05 (40eecd594ac) get SIGSEGV on Linux (Linux 6.6.45 Kde Wayland)

From: Pip Cet <[email-masked]>
Date: Wed, 28 Aug 2024 17:56:08 +0000

"Juri Linkov" <[email-masked]> writes:

>>> > I see Eli reverted the change, which makes sense for now.  We'll have to
>>> > find another way to fix this, I think.
>>>
>>> I'm ready to test any changes when you'll find another way to fix this.
>>
>> Thanks, please test the patch below.  If it doesn't adversely affect
>> performance, I will install it.
>
> With the previous change, when leaning on an arrow key, cursor motion
> was visibly laggy since the cursor skipped 3-4 characters.
>
> Now with this patch, the cursor visits every character without delays.

Excellent.

> OTOH, I tried to set a breakpoint inside 'if (non_basic_faces_cached)',
> and it's never visited.  So it seems this change has no effect
> in normal circumstances.

I'm not sure that's the right way around: we try to execute the code
inside 'if (non_basic_faces_cached)' as rarely as possible, with Eli's
change, and never executing it at all is the best possible outcome (and
the expected one if no non-standard faces or non-ASCII characters are in
use).

Pip