Don't crash when source or target is null

Change-Id: I4992867ad764bd1bd175478c6be1094ca8a72812
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

1 files changed, 18 insertions, 2 deletions

diff --git a/src/gui/opengl/qopenglframebufferobject.cpp b/src/gui/opengl/qopenglframebufferobject.cpp
index 6714ea3d49..5e22554303 100644
--- a/src/gui/opengl/qopenglframebufferobject.cpp
+++ b/src/gui/opengl/qopenglframebufferobject.cpp
@@ -1142,8 +1142,24 @@ void QOpenGLFramebufferObject::blitFramebuffer(QOpenGLFramebufferObject *target,
                                                QOpenGLFramebufferObject *source,
                                                GLbitfield buffers, GLenum filter)
 {
-    blitFramebuffer(target, QRect(QPoint(0, 0), target->size()),
-                    source, QRect(QPoint(0, 0), source->size()),
+    if (!target && !source)
+        return;
+
+    QSize targetSize;
+    QSize sourceSize;
+
+    if (target)
+        targetSize = target->size();
+    if (source)
+        sourceSize = source->size();
+
+    if (targetSize.isEmpty())
+        targetSize = sourceSize;
+    else if (sourceSize.isEmpty())
+        sourceSize = targetSize;
+
+    blitFramebuffer(target, QRect(QPoint(0, 0), targetSize),
+                    source, QRect(QPoint(0, 0), sourceSize),
                     buffers, filter);
 }