Re: [gta-list] Imagemagick test fails randomly

[Volker Froehlich]

On Sun, 2013-02-03 at 15:16 +0100, Martin Lambers wrote:
> Hi Volker!
> 
> On Sun, 03 Feb 2013 14:27:32 +0100, Volker Froehlich wrote:
> > The imagemagick test of gtatool 1.5 seems to fail randomly in Fedora
> > 16 and 17. It always seems to pass in Fedora 18 though. I didn't
> > notice this behaviour with gtatool 1.4. libgta version is 1.0.2 in
> > all cases.
> > 
> > Imagemagick versions are:
> > 
> > F16: 6.7.0.10 (fails randomly)
> > F17: 6.7.5.6 (fails randomly)
> > F18: 6.7.7.5 (seems working)
> 
> Thanks for reporting this! I cannot reproduce the problem on Ubuntu,
> but I have two guesses: 
> 1) Some versions of ImageMagick might write a file creation stamp into
> a generated image, so that 'cmp' in the test script fails.
> 2) The random crashes may be related to threading/locking issues inside
> ImageMagick. I have seen similar problems on Windows, but not yet on
> Linux. I have no idea how the test can 'PASS' in that case; the test
> scripts use 'set -e' which should abort immediately.
> 
> I pushed a patch that changes the library initialization, which might
> make it more predictable, and that changes the image format used in the
> test script to ppm, which cannot store metadata. See
> http://git.savannah.gnu.org/cgit/gta.git/commit/?id=8a4cba71a35fa19eb58c111d6a376e181f642ae0
> 
> This should at least fix 1), but I'm not sure about 2).

I'm afraid it fixes neither for me. It still fails at random. I'm
confident now though, that the problem is only connected to ImageMagick
and nothing else: I rebuilt F18's ImageMagick in F16 and the test
doesn't fail anymore.

gtatool 1.4, ImageMagick 6.7.0.10 -- Works fine
gtatool 1.5 (with and without patch), ImageMagick 6.7.0.10 -- Fails
sometimes
gtatool 1.5, ImageMagick 6.7.7.5 -- Works fine (Rebuilt for F16)

Volker

> To be absolutely identical to gtatool-1.4.0 code, I could remove the
> InitializeMagick() call altogether. But that is not recommended and
> does not work on all platforms.
> 
> I also have a patch that replaces ImageMagick with GraphicsMagick, but
> on Windows that leads to the exact same threading problems, so I'm not
> sure it is worth trying that on Linux.
> 
> Greetings,
> Martin