Bug#812093: libimager-perl: FTBFS: Failed 1/65 test programs. 0/4481 subtests failed.

[Tony Cook]

On Wed, Jan 20, 2016 at 10:38:27PM +0200, Niko Tyni wrote:
> On Wed, Jan 20, 2016 at 02:42:04PM +0100, Chris Lamb wrote:
> > Source: libimager-perl
> > Version: 1.004+dfsg-1
> > Severity: serious
> > Justification: fails to build from source
> > User: reproducible-builds at lists.alioth.debian.org
> > Usertags: ftbfs
> > X-Debbugs-Cc: reproducible-builds at lists.alioth.debian.org
> 
> > libimager-perl fails to build from source in unstable/amd64:
> 
> It broke with src:giflib 5.1.2-0.1 -> 5.1.1-0.2. Don't know
> why yet.
> 
> % perl -MImager -e 'Imager->new->read(type => "gif", file => "GIF/testimg/expected.gif") or die'
> 
> dies with the new giflib but not the old one.
> 
> Cc'ing Matthias Klose as a heads-up, he uploaded 5.1.1-0.2.

The read failures are caused by a bug present in both 5.1.1 and 5.1.2,
partly fixed in giflib git at commit
ef0cb9b4be572262b49fbc26fb2348683f44a517.

A similar fix is required to DGifOpen() for Imager's GIF support to
work (reliably), reported upstream as
https://sourceforge.net/p/giflib/bugs/81/

Without the fix the Private member RunningBits isn't initialized,
leaving RunningBits as whatever happened to be in memory at that
point, so the check in DGifSetupDecompress() has a large chance of
failing with a D_GIF_ERR_READ_FAILED error.

Adding the initialization allows Imager to pass its tests.

That said, there is a bug in that test script, since its custom ok()
doesn't have a prototype, the tests on line 65 and 78 pass when they
should fail, leading to the crash on line 79 when it tries to compare
uninitialized images.

Adding a prototype fixes it, though I'll probably end up tossing the
custom code and using Test::More.

Tony