composite: Make compIsAlternateVisual safe even if Composite is off

As of ea483af9 we're calling this unconditionally from the GLX code so
the synthetic visual is in a lower select group. If Composite has been
disabled then GetCompScreen() will return NULL, and this would crash.

Rather than force the caller to check first, just always return FALSE if
Composite is disabled (which is correct, since none of the visuals will
be synthetic in that case).

Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Aaron Plattner <aplattner@nvidia.com>
(cherry picked from commit f80119120c)
This commit is contained in:
Adam Jackson 2017-07-27 16:02:28 -04:00
parent 06d1c83d04
commit 0a73e7bf10

View File

@ -326,7 +326,7 @@ compIsAlternateVisual(ScreenPtr pScreen, XID visual)
CompScreenPtr cs = GetCompScreen(pScreen);
int i;
for (i = 0; i < cs->numAlternateVisuals; i++)
for (i = 0; cs && i < cs->numAlternateVisuals; i++)
if (cs->alternateVisuals[i] == visual)
return TRUE;
return FALSE;