Merge lp:~dandrader/unity/lp942625 into lp:unity

[Daniel d'Andrada]

Fixes 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.

Also includes some other safeguards around the same issue.

UNBLOCK

[Andrea Cimitan (cimi)]

8 + Status status;
9
10 XQueryTree(_screen->dpy(), window, &root, &parent, &children, &nchildren);
11 + if (status == 0)
12 + break;

Did you forget to initialize 'status'?

review: Needs Fixing

[Daniel d'Andrada (dandrader)]

> 8 + Status status;
> 9
> 10 XQueryTree(_screen->dpy(), window, &root, &parent, &children,
> &nchildren);
> 11 + if (status == 0)
> 12 + break;
>
> Did you forget to initialize 'status'?

Yes indeed.

[Daniel d'Andrada (dandrader)]

Patch updated.

[Andrea Cimitan (cimi)]

Fixes the bug for me

[Marco Trevisan (Treviño) (3v1n0)]

+1

review: Approve

=== modified file 'plugins/unityshell/src/GestureEngine.cpp'
--- plugins/unityshell/src/GestureEngine.cpp	2012-02-04 05:28:23 +0000
+++ plugins/unityshell/src/GestureEngine.cpp	2012-03-01 20:53:28 +0000
@@ -85,13 +85,18 @@
     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 @@
 void
 GestureEngine::OnTouchStart(GeisAdapter::GeisTouchData* data)
 {
-  if (data->touches == 3)
+  if (data->touches == 3 && data->window != 0)
   {
     CompWindow* result = FindCompWindow(data->window);