bug#21716: 25.0.50; highlight-regexp gets confused when the highlighted text is pasted

bug#21716: 25.0.50; highlight-regexp gets confused when the highlighted text is pasted

[Dima Kogan]

Hi. I'm running a recent build of emacs: 

  https://github.com/emacs-mirror/emacs/commit/ce402dd

and I'm observing highlight-regexp get confused some times. Recipe:

1. emacs -Q

2. open or type a tiny .c source file such as:
=====================
int main(void)
{

}
=====================

3. mark 'main' and M-w

4. highlight 'main': M-s h r main, accept default face

5. yank on the empty line between {}. I expect the yanked text 'main' to
be highlighted. Instead I sometimes see "mai" being highlighted but not
the "n"; at other times I see nothing highlighted, but "mai" being
rendered with a different face than the "n". In any case, it's never
highlighted correctly.

bug#21716: 25.0.50; highlight-regexp gets confused when the highlighted text is pasted

[Eli Zaretskii]

> From: Dima Kogan <dima@secretsauce.net>
> Date: Mon, 19 Oct 2015 23:13:19 -0700
> 
> 1. emacs -Q
> 
> 2. open or type a tiny .c source file such as:
> =====================
> int main(void)
> {
> 
> }
> =====================
> 
> 3. mark 'main' and M-w
> 
> 4. highlight 'main': M-s h r main, accept default face
> 
> 5. yank on the empty line between {}. I expect the yanked text 'main' to
> be highlighted. Instead I sometimes see "mai" being highlighted but not
> the "n"; at other times I see nothing highlighted, but "mai" being
> rendered with a different face than the "n". In any case, it's never
> highlighted correctly.

What I see here is that the moment 'main' becomes a complete C symbol,
like if I type a ';' or a '(' after yanking it, "main" becomes
highlighted exactly as expected.  So maybe this is a feature?

I do see that Emacs 24.5 highlighted "main" as soon as it was yanked,
so this is at least a change in behavior.

bug#21716: 25.0.50; highlight-regexp gets confused when the highlighted text is pasted

[Lars Ingebrigtsen]

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Dima Kogan <dima@secretsauce.net> writes:

> 2. open or type a tiny .c source file such as:
> =====================
> int main(void)
> {
>
> }
> =====================
>
> 3. mark 'main' and M-w
>
> 4. highlight 'main': M-s h r main, accept default face
>
> 5. yank on the empty line between {}. I expect the yanked text 'main' to
> be highlighted. Instead I sometimes see "mai" being highlighted but not
> the "n"; at other times I see nothing highlighted, but "mai" being
> rendered with a different face than the "n". In any case, it's never
> highlighted correctly.

I've tried the recipe in Emacs 28, and this seems to work better now:


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So I'm going to go ahead and guess that this has been fixed in the five
years since this was reported, and I'm closing this bug report.  If you
can still see the bug, please respond to the debbugs address and we'll
reopen.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#21716: 25.0.50; highlight-regexp gets confused when the highlighted text is pasted

[Dima Kogan]

Yeah, it appears to work now. Thanks much for going through the old
reports.