QWindowCompositor: Prevent double delete.

With a SHM client, if a null attach happened, then the old buffer would be
deleted but left with a dangling pointer which would be deleted again on the
destructor.

This was revealed by tst_dialog.

Change-Id: I89e22487e7ec982789a4b7dfd45e5db7db3222d1
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/examples/qwindow-compositor/qwindowcompositor.cpp b/examples/qwindow-compositor/qwindowcompositor.cpp
index a17af929d..73182ba33 100644
--- a/examples/qwindow-compositor/qwindowcompositor.cpp
+++ b/examples/qwindow-compositor/qwindowcompositor.cpp
@@ -75,10 +75,12 @@ public:
     void attach(const QWaylandBufferRef &ref) Q_DECL_OVERRIDE
     {
         if (bufferRef) {
-            if (bufferRef.isShm())
+            if (bufferRef.isShm()) {
                 delete shmTex;
-            else
+                shmTex = 0;
+            } else {
                 bufferRef.destroyTexture();
+            }
         }
 
         bufferRef = ref;