Merge remote-tracking branch 'origin/5.6' into 5.7

Conflicts:
	src/angle/src/libGLESv2/libGLESv2.pro
	src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp

Change-Id: If8da4cfe8f57fea9f78e7239f378a6302c01674e

1 files changed, 5 insertions, 1 deletions

diff --git a/src/plugins/platforms/ios/qioscontext.mm b/src/plugins/platforms/ios/qioscontext.mm
index d18e317bfb..50374dc951 100644
--- a/src/plugins/platforms/ios/qioscontext.mm
+++ b/src/plugins/platforms/ios/qioscontext.mm
@@ -217,8 +217,12 @@ void QIOSContext::swapBuffers(QPlatformSurface *surface)
     if (surface->surface()->surfaceClass() == QSurface::Offscreen)
         return; // Nothing to do
 
+    // When using threaded rendering, the render-thread may not have picked up
+    // yet on the fact that a window is no longer exposed, and will try to swap
+    // a non-exposed window. This may in some cases result in crashes, e.g. when
+    // iOS is suspending an application, so we have an extra guard here.
     if (!static_cast<QIOSWindow *>(surface)->isExposed()) {
-        qCWarning(lcQpaGLContext, "Detected swapBuffers on a non-exposed window, skipping flush");
+        qCDebug(lcQpaGLContext, "Detected swapBuffers on a non-exposed window, skipping flush");
         return;
     }