Strange wined3d crash

[Henri Verbeet]

On 29 April 2015 at 19:02, Matteo Bruni <matteo.mystral at gmail.com> wrote:
> Essentially it crashes in shader_vaddline() as soon as we have to
> resize the buffer because vsnprintf() tries to use "args" for a second
> time.
Oops. I guess this really got broken with
cf12f51b1520546dc855e8e8e43135a06e7a0cbf already, but the larger
initial buffer size made it work most of the time.

> I attached a fix. Henri, is something like that okay with you?
In principle, but I think va_copy() is C99; I'm not sure we can rely
on it being present. Since shader_vaddline() only has a couple of
callers, it may be better to just move the resizing code into a helper
function and use that from the callers.