Prevent always deep-copying in QPixmap::toImage() for raster pixmaps.

Calling paintEngine() can cause a deep copy since it will indirectly
call the bits() function. Since we don't want to create a paint engine
if it doesn't exist we should access the QImageData paintEngine variable
directly instead.

Reviewed-by: Olivier Goffart

2 files changed, 12 insertions, 11 deletions

diff --git a/src/gui/image/qpixmap_raster.cpp b/src/gui/image/qpixmap_raster.cpp
index f080687..29bf5f5 100644
--- a/src/gui/image/qpixmap_raster.cpp
+++ b/src/gui/image/qpixmap_raster.cpp
@@ -50,6 +50,7 @@
 #include "qimage.h"
 #include <QBuffer>
 #include <QImageReader>
+#include <private/qimage_p.h>
 #include <private/qsimd_p.h>
 #include <private/qwidget_p.h>
 #include <private/qdrawhelper_p.h>
@@ -303,11 +304,13 @@ bool QRasterPixmapData::hasAlphaChannel() const
 
 QImage QRasterPixmapData::toImage() const
 {
-    if (image.paintEngine()
-        && image.paintEngine()->isActive()
-        && image.paintEngine()->paintDevice() == &image)
-    {
-        return image.copy();
+    if (!image.isNull()) {
+        QImageData *data = const_cast<QImage &>(image).data_ptr();
+        if (data->paintEngine && data->paintEngine->isActive()
+            && data->paintEngine->paintDevice() == &image)
+        {
+            return image.copy();
+        }
     }
 
     return image;
diff --git a/tests/auto/qpixmap/tst_qpixmap.cpp b/tests/auto/qpixmap/tst_qpixmap.cpp
index d5267b5..419518a1 100644
--- a/tests/auto/qpixmap/tst_qpixmap.cpp
+++ b/tests/auto/qpixmap/tst_qpixmap.cpp
@@ -129,10 +129,7 @@ private slots:
     void isNull();
     void task_246446();
 
-#ifdef Q_WS_QWS
     void convertFromImageNoDetach();
-#endif
-
     void convertFromImageDetach();
 
 #if defined(Q_WS_WIN)
@@ -913,11 +910,13 @@ void tst_QPixmap::isNull()
     }
 }
 
-#ifdef Q_WS_QWS
 void tst_QPixmap::convertFromImageNoDetach()
 {
+    QPixmap randomPixmap(10, 10);
+    if (randomPixmap.pixmapData()->classId() != QPixmapData::RasterClass)
+        QSKIP("Test only valid for raster pixmaps", SkipAll);
+
     //first get the screen format
-    QPixmap randomPixmap(10,10);
     QImage::Format screenFormat = randomPixmap.toImage().format();
     QVERIFY(screenFormat != QImage::Format_Invalid);
 
@@ -932,7 +931,6 @@ void tst_QPixmap::convertFromImageNoDetach()
     const QImage constCopy = copy;
     QVERIFY(constOrig.bits() == constCopy.bits());
 }
-#endif //Q_WS_QWS
 
 void tst_QPixmap::convertFromImageDetach()
 {