bug#54629: 29.0.50; Emacs crashes when I try to move scroll bar by grabbing it with mouse

[Po Lu]

Eric Spero <eric@ericspero.com> writes:

> Ok, here are the steps I took.
>
> 1. gdb /usr/bin/emacs
> 2. run -Q
> 3. [try to pull scroll bar down]
> 4. bt
>
> gdb produced a bit output after I tried to pull the scroll bar down,
> starting at "Fatal error 6: Aborted".
>
> Please let me know if I've done anything wrong, or if there is
> anything else I can provide.

Thanks.  This is because the PGTK port assumes toolkit scroll bars are
always available, but compiling without them causes the wrong code to be
enabled in keyboard.c, which then aborts upon "unexpected" scroll bar
events.

I will update the configure script to disallow this specific
configuration, but in the meantime, please tell the Gentoo developers to
fix their build script.

Please tell them to also turn PGTK off by default, people shouldn't be
using it on X.