Fixes infinite loop in GestureEngine. lp:942625

GestureEngine::FindCompWindow() would enter in an infinite loop if the window passed to it is the root window since its break condition (parent == root) would never be reached as parent would be zero. Fixes LP: #942625 (bzr r2044.2.1)

1 files changed, 8 insertions, 3 deletions

diff --git a/plugins/unityshell/src/GestureEngine.cpp b/plugins/unityshell/src/GestureEngine.cpp
index 96110111f..5a72843cb 100644
--- a/plugins/unityshell/src/GestureEngine.cpp
+++ b/plugins/unityshell/src/GestureEngine.cpp
@@ -85,13 +85,18 @@ GestureEngine::FindCompWindow(Window window)
 Window parent, root;
 Window* children = NULL;
 unsigned int nchildren;
+ Status status;
 
- XQueryTree(_screen->dpy(), window, &root, &parent, &children, &nchildren);
+ status = XQueryTree(_screen->dpy(), window, &root, &parent, &children, &nchildren);
+ if (status == 0)
+ break;
 
 if (children)
 XFree(children);
 
- if (parent == root)
+ // parent will be zero when the window passed to this method is already the
+ // root one.
+ if (parent == root || parent == 0)
 break;
 
 window = parent;
@@ -215,7 +220,7 @@ GestureEngine::OnRotateFinish(GeisAdapter::GeisRotateData* data)
 void
 GestureEngine::OnTouchStart(GeisAdapter::GeisTouchData* data)
 {
- if (data->touches == 3)
+ if (data->touches == 3 && data->window != 0)
 {
 CompWindow* result = FindCompWindow(data->window);