Fix QOpenGLWidget/QQuickWidget GUI freeze

A window with a renderToTexture child uses the OpenGL path, but when
we open a popup or dialog, that uses the raster compositor, which opens
a separate surface. This patch fixes two issues when combining GL rendering
with the raster compositor:

1. GL-rendered widgets were counted as part of the raster-rendered region,
meaning that we did not punch a hole in the raster surface.

2. We did not destroy the surface when no longer needed.

Task-number: QTBUG-41467
Change-Id: I2a2a0e860cce065b330df1c864d51fd02103aa1b
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>
Reviewed-by: BogDan Vatra <bogdan@kde.org>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/src/plugins/platforms/android/qandroidplatformscreen.cpp b/src/plugins/platforms/android/qandroidplatformscreen.cpp
index 684ae64703..b70f936be1 100644
--- a/src/plugins/platforms/android/qandroidplatformscreen.cpp
+++ b/src/plugins/platforms/android/qandroidplatformscreen.cpp
@@ -284,9 +284,9 @@ void QAndroidPlatformScreen::doRedraw()
     if (m_dirtyRect.isEmpty())
         return;
 
-    // Stop if there no visible raster windows. This is important because if we only have
-    // RasterGLSurface windows that have renderToTexture children (i.e. they need the
-    // OpenGL path) then we must bail out right now.
+    // Stop if there are no visible raster windows. If we only have RasterGLSurface
+    // windows that have renderToTexture children (i.e. they need the OpenGL path) then
+    // we do not need an overlay surface.
     bool hasVisibleRasterWindows = false;
     foreach (QAndroidPlatformWindow *window, m_windowStack) {
         if (window->window()->isVisible() && window->isRaster() && !qt_window_private(window->window())->compositing) {
@@ -294,9 +294,13 @@ void QAndroidPlatformScreen::doRedraw()
             break;
         }
     }
-    if (!hasVisibleRasterWindows)
+    if (!hasVisibleRasterWindows) {
+        if (m_id != -1) {
+            QtAndroid::destroySurface(m_id);
+            m_id = -1;
+        }
         return;
-
+    }
     QMutexLocker lock(&m_surfaceMutex);
     if (m_id == -1 && m_rasterSurfaces) {
         m_id = QtAndroid::createSurface(this, m_availableGeometry, true, m_depth);
@@ -339,6 +343,7 @@ void QAndroidPlatformScreen::doRedraw()
     QRegion visibleRegion(m_dirtyRect);
     foreach (QAndroidPlatformWindow *window, m_windowStack) {
         if (!window->window()->isVisible()
+                || qt_window_private(window->window())->compositing
                 || !window->isRaster())
             continue;