bug#37137: Setting font-lock-case-fold-search to t causes hangs on certain types in c-mode

[Zachary Napier]

Hello Alen and Stefan,

> May I ask why you're making this setting?

> How did you end up with that?
> font-lock-keywords-case-fold-search is not a customize variable, so you
> should not set it with custom-set-variables.

I inherited this .emacs file from someone else who had this
set. I'm guessing it used to be customizable? If it really isn't
proper to customize it this way thats fine. I can disable it with
no real issues. I can just change the regexps I am using in
font-lock-add-keywords. I assumed that it could be customized
because if I did a search the customize option for it showed up,
but maybe improperly setting it with custom-set-variables just
adds it to Customize.

On Sun, Aug 25, 2019 at 11:12 AM Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> I have in my .emacs file only these two lines:
>
>     (custom-set-variables
>      '(font-lock-keywords-case-fold-search t))

How did you end up with that?
font-lock-keywords-case-fold-search is not a customize variable, so you
should not set it with custom-set-variables.

> Then if I visit an empty or nonexistent C file and just type "LONG"
> (in all caps or with at least one letter being capital), Emacs will
> hang after typing the final G but before the G appears on screen

Clearly not a desirable behavior, indeed, but the above var setting is
clearly a pilot error.  Of course

    (setq-default font-lock-keywords-case-fold-search t)

would give the same result, but I'd also argue that it'd be
a pilot error.


        Stefan