[FFmpeg-devel] Workaround for VS 2015 Update 1 bug

[Bruce Dawson]

> Can you elaborate which test should be failing?

Sure.

The test that is failing is not in the ffmpeg repo, but it uses the ffmpeg
repo. The Chromium test that fails (debug and release because we always
compile ffmpeg optimized) is this one:

media_unittests.exe --single-process-tests
--gtest_filter=AudioVideoMetadataExtractorTest.AudioWAV

Because ff_read_riff_info() ends up not null-terminating the key array it
means that the value of 'key' passed to av_dict_set() is undefined. In some
cases it might actually be correct, or it could be an arbitrarily long
string, or their could be an access violation.

It is also possible to verify the bug through inspection of the generated
code, but that is tedious. More details, including a minimal repro, can be
found in the connect bug:

https://connect.microsoft.com/VisualStudio/feedback/details/2291638

On Thu, Jan 28, 2016 at 1:52 PM, Hendrik Leppkes <h.leppkes at gmail.com>
wrote:

> Am 28.01.2016 22:14 schrieb "Bruce Dawson" <brucedawson at google.com>:
> >
> > I hit a VS 2015 Update 1 code-gen bug that causes an string array to not
> be
> > null-terminated. I've already landed a patch in Chromium's downstream
> copy,
> > to unblock the failing test and I wanted to offer up the same patch for
> the
> > main ffmpeg repo.
>
> Can you elaborate which test should be failing? I run both x86 and x64
> setups with MSVC 2015 U1 in our FATE setup and everything seems to be
> perfectly fine on that end.
>
> >
> > The patch is attached. It's quite simple. There are other workarounds
> that
> > also work but this is the one that landed in Chromium's copy so I prefer
> > it, to avoid conflicts.
> >
> > The bug has been confirmed by Microsoft and should be fixed in the next
> > version of the compiler.
> >
> > --
> > Bruce Dawson
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
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-- 
Bruce Dawson