surface: Fix crash when accessing null

This patch adds a null check before accessing the return value of
ds_subsurface_from_surface().

The return value of ds_subsurface_from_surface() can be null even though
the ds_surface_is_subsurface() returns true. That's the case when the
subsurface has been destroyed.

Change-Id: I112dd4770b678f73e946be9773633083db8ce68b

diff --git a/src/compositor/surface.c b/src/compositor/surface.c
index 5f883cc..b6a103b 100644 (file)
--- a/src/compositor/surface.c
+++ b/src/compositor/surface.c
@@ -582,8 +582,8 @@ surface_handle_commit(struct wl_client *client, struct wl_resource *resource)
 
     ds_dbg("ds_surface(%p) commit", surface);
 
-    if (ds_surface_is_subsurface(surface)) {
-        subsurface = ds_subsurface_from_surface(surface);
+    subsurface = ds_subsurface_from_surface(surface);
+    if (subsurface) {
         subsurface_commit(subsurface);
         return;
     }