Fix for talloc, in order to improve mesa shader compiler performance on windows from abysmal to m...

Fix for talloc, in order to improve mesa shader compiler performance on windows from abysmal to merely poor.  The vsnprintf() implementation in MSVC's libc does not conform to C99, and returns -1 if the given buffer is too small to hold the given format.  Passing it NULL and a size of zero returns the number of chars required.

BUG=NONE
TEST=all GPU layout tests
R=kbr
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=78710

[Stephen White, 2011-03-18 14:27:02]

This works on all platforms, but I can wrap it in an compiler-specific #ifdef if
you like.

[Ken Russell (switch to Gerrit), 2011-03-18 16:54:10]

Thanks for tracking that down.

LGTM, but could you also update the README.chromium and chromium.patch? To avoid
having to download talloc 2.0.1 you could apply the existing patch with -r to
the current talloc.c to produce the 2.0.1 file.

[Stephen White, 2011-03-18 17:10:12]

On 2011/03/18 16:54:10, kbr wrote:
> Thanks for tracking that down.
> 
> LGTM, but could you also update the README.chromium and chromium.patch?

Done.

[Ken Russell (switch to Gerrit), 2011-03-18 17:14:49]

LGTM; thanks a lot.