Fix corruption of Direct Show event queue.

The mutex proctecting the queue was being released and reacquired
between when the head and tail are cleared, making it possible to append
a new item to a popped, or even deleted tail, resulting in a lost event.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/plugins/mediaservices/directshow/mediaplayer/directshoweventloop.cpp b/src/plugins/mediaservices/directshow/mediaplayer/directshoweventloop.cpp
index 4f9a19d..07541c2 100644
--- a/src/plugins/mediaservices/directshow/mediaplayer/directshoweventloop.cpp
+++ b/src/plugins/mediaservices/directshow/mediaplayer/directshoweventloop.cpp
@@ -148,13 +148,14 @@ void DirectShowEventLoop::processEvents()
         DirectShowPostedEvent *post = m_postsHead;
         m_postsHead = m_postsHead->next;
 
+        if (!m_postsHead)
+            m_postsTail = 0;
+
         locker.unlock();
         QCoreApplication::sendEvent(post->receiver, post->event);
         delete post;
         locker.relock();
     }
-
-    m_postsTail = 0;
 }
 
 QT_END_NAMESPACE