bug#46025: 28.0.50; warning suppression buttons truncate warnings

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Tue, 20 Apr 2021 22:19:31 -0500
> Cc: 46025@debbugs.gnu.org
> 
> Yes, it seems useless to have these buttons in their current form.
> 
> Could we at least disable them until they are fixed to not truncate
> warnings?  They hide the contents of legitimate warnings.

AFAIK, the warnings are only truncated when they are VERY long, as in
the case above, where they show the backtrace from the Lisp debugger.
Originally, there was a bug that would cause almost every message be
truncated, but that was fixed.

Not sure what to do with warnings that show backtraces.