Avoid deadlock during window hiding.

Because we do event processing in polishAndSync, hide() or
handleObscurity() might have been called by the time we
continue execution. We already handled that windowDestroyed()
was called.

Change-Id: If45bcf3fa18cef1a60ca31bc26d3830045f581d9
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index 38318fdd00..f8771e68cf 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -886,6 +886,10 @@ void QSGThreadedRenderLoop::handleExposure(QQuickWindow *window)
         w = &m_windows.last();
     }
 
+    // set this early as we'll be rendering shortly anyway and this avoids
+    // specialcasing exposure in polishAndSync.
+    w->thread->window = window;
+
     if (w->window->width() <= 0 || w->window->height() <= 0
             || !w->window->geometry().intersects(w->window->screen()->availableGeometry())) {
 #ifndef QT_NO_DEBUG
@@ -1074,7 +1078,7 @@ void QSGThreadedRenderLoop::polishAndSync(Window *w, bool inExpose)
     QSG_GUI_DEBUG(w->window, "polishAndSync()");
 
     QQuickWindow *window = w->window;
-    if (!window->isExposed() || !window->isVisible() || window->size().isEmpty()) {
+    if (!w->thread || !w->thread->window) {
         QSG_GUI_DEBUG(w->window, " - not exposed, aborting...");
         killTimer(w->timerId);
         w->timerId = 0;
@@ -1093,7 +1097,7 @@ void QSGThreadedRenderLoop::polishAndSync(Window *w, bool inExpose)
         QQuickWindowPrivate::get(window)->flushDelayedTouchEvent();
         w = windowFor(m_windows, window);
     }
-    if (!w) {
+    if (!w || !w->thread || !w->thread->window) {
         QSG_GUI_DEBUG(w->window, " - removed after event flushing..");
         killTimer(w->timerId);
         w->timerId = 0;