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From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: [PATCH] Fix compilation erorr when --enable-gcc-warnings passed
Date: Sat, 23 Jan 2016 11:23:11 +0200
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To: Paul Eggert <eggert@cs.ucla.edu>
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> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sat, 23 Jan 2016 01:08:08 -0800
> Cc: emacs-devel@gnu.org
> 
> I installed a patch into emacs-25 to replace the compile-time warning with a 
> run-time crash, if you configure --with-cairo --enable-checking and visit a .png 
> file.

If we know in advance that some scenario doesn't work, then eassert is
not TRT.  We should signal an error instead.  eassert is for things
that "cannot happen", i.e. they are there to help us discover the
(unknown) scenarios where our assumptions are false.  In this case,
the scenario is already known, and moreover it is very simple to
trigger, so aborting is not the best strategy.