sna: Fixup early assert of xf86ScrnToScreen

During early init, xf86ScrnToScreen() may return NULL, so handle that
possibility inside the assert.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/sna/sna.h b/src/sna/sna.h
index c9097d3d..3ccc74c8 100644
--- a/src/sna/sna.h
+++ b/src/sna/sna.h
@@ -509,7 +509,7 @@ to_sna_from_screen(ScreenPtr screen)
 pure static inline ScreenPtr to_screen_from_sna(struct sna *sna)
 {
 	ScreenPtr screen = xf86ScrnToScreen(sna->scrn);
-	assert(sna == to_sna_from_screen(screen));
+	assert(!screen || sna == to_sna_from_screen(screen));
 	return screen;
 }