Prevented assert on 1 pixel wide / high images in qt_blurImage.

Don't attempt to run qt_halfScaled on images less than 2px in either
dimension. Particularly, avoid doing this from qt_blurImage, where
that situation can happen as a result of a clipped QGraphicsEffect.

Reviewed-by: Bjørn Erik Nilsen

1 files changed, 4 insertions, 1 deletions

diff --git a/src/gui/image/qpixmapfilter.cpp b/src/gui/image/qpixmapfilter.cpp
index 2792e45..c605880 100644
--- a/src/gui/image/qpixmapfilter.cpp
+++ b/src/gui/image/qpixmapfilter.cpp
@@ -777,6 +777,9 @@ void expblur(QImage &img, qreal radius, bool improvedQuality = false, int transp
 
 Q_GUI_EXPORT QImage qt_halfScaled(const QImage &source)
 {
+    if (source.width() < 2 || source.height() < 2)
+        return QImage();
+
     QImage srcImage = source;
 
     if (source.format() == QImage::Format_Indexed8) {
@@ -869,7 +872,7 @@ Q_GUI_EXPORT void qt_blurImage(QPainter *p, QImage &blurImage, qreal radius, boo
     }
 
     qreal scale = 1;
-    if (radius >= 4) {
+    if (radius >= 4 && blurImage.width() >= 2 && blurImage.height() >= 2) {
         blurImage = qt_halfScaled(blurImage);
         scale = 2;
         radius *= qreal(0.5);