3 files changed, 8 insertions, 0 deletions
diff --git a/src/gui/image/qpixmap_raster.cpp b/src/gui/image/qpixmap_raster.cpp
index 5c188f0362..30463f3c0d 100644
--- a/src/gui/image/qpixmap_raster.cpp
+++ b/src/gui/image/qpixmap_raster.cpp
@@ -353,7 +353,9 @@ void QRasterPlatformPixmap::createPixmapForImage(QImage &sourceImage, Qt::ImageC
     is_null = (w <= 0 || h <= 0);
 
     image.d->devicePixelRatio = sourceImage.devicePixelRatio();
+    //ensure the pixmap and the image resulting from toImage() have the same cacheKey();
     setSerialNumber(image.cacheKey() >> 32);
+    setDetachNumber(image.d->detach_no);
 }
 
 QImage* QRasterPlatformPixmap::buffer()
diff --git a/src/gui/image/qplatformpixmap.cpp b/src/gui/image/qplatformpixmap.cpp
index 2e12ae2e91..1d147e3d3c 100644
--- a/src/gui/image/qplatformpixmap.cpp
+++ b/src/gui/image/qplatformpixmap.cpp
@@ -173,6 +173,11 @@ void QPlatformPixmap::setSerialNumber(int serNo)
     ser_no = serNo;
 }
 
+void QPlatformPixmap::setDetachNumber(int detNo)
+{
+    detach_no = detNo;
+}
+
 QImage QPlatformPixmap::toImage(const QRect &rect) const
 {
     if (rect.contains(QRect(0, 0, w, h)))
diff --git a/src/gui/image/qplatformpixmap.h b/src/gui/image/qplatformpixmap.h
index af3abecaf8..d54f31099e 100644
--- a/src/gui/image/qplatformpixmap.h
+++ b/src/gui/image/qplatformpixmap.h
@@ -132,6 +132,7 @@ public:
 protected:
 
     void setSerialNumber(int serNo);
+    void setDetachNumber(int detNo);
     int w;
     int h;
     int d;