bug#47162: Mouse Wheel Won't Work When Emacs Built without Any Window System

[Basil L. Contovounesios]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 张强 <johnson9009@163.com>, 47162@debbugs.gnu.org
>> Date: Fri, 30 Jul 2021 09:32:22 +0100
>> From:  "Basil L. Contovounesios" via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> > I've now made this change in Emacs 28.
>> 
>> FYI, as a result of this change mwheel is now effectively preloaded even
>> --without-x, in the sense that (featurep 'mwheel) returns non-nil even
>> when starting nox builds with -Q (see my signature for details).
>> 
>> Bother or feature?
>
> It's probably a bother, but could you please show the details, like
> what causes mwheel to be loaded at startup or at loadup time in the
> "--without-x" builds?

I built Emacs before and after commit 0aad4d134f, and attach the
resulting configurations as well as their diff.  Note that some other
libraries such as pp are also being loaded in the latter configuration.

After the autoload, I get the attached GDB backtrace with the following:

0. gdb ./emacs
1. set logging file gdb-after.txt
2. set logging on
3. b lread.c:1215 if !strncmp (SDATA (file), "mwheel", 6)
4. r -Q
5. bt

So it seems to be the reevaluation of custom-delayed-init-variables in
command-line that is loading mwheel at startup.

-- 
Basil

configuration-before.txt
Description: Emacs configuration before autoload

configuration-after.txt
Description: Emacs configuration after autoload

configuration.diff
Description: Diff of Emacs configurations before and after autoload

gdb-after.txt
Description: GDB backtrace after autoload