Make sure to do a deep copy of a QImage when it's being painted on.

Not doing so can produce some hard-to-track-down bugs in the app.

Task-number: QTBUG-15749
Reviewed-by: Gunnar Sletta

2 files changed, 25 insertions, 8 deletions

diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 1157b93..6ba3858 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -1121,9 +1121,14 @@ QImage::QImage(const char * const xpm[])
 QImage::QImage(const QImage &image)
     : QPaintDevice()
 {
-    d = image.d;
-    if (d)
-        d->ref.ref();
+    if (image.paintingActive()) {
+        d = 0;
+        operator=(image.copy());
+    } else {
+        d = image.d;
+        if (d)
+            d->ref.ref();
+    }
 }
 
 #ifdef QT3_SUPPORT
@@ -1320,11 +1325,15 @@ QImage::~QImage()
 
 QImage &QImage::operator=(const QImage &image)
 {
-    if (image.d)
-        image.d->ref.ref();
-    if (d && !d->ref.deref())
-        delete d;
-    d = image.d;
+    if (image.paintingActive()) {
+        operator=(image.copy());
+    } else {
+        if (image.d)
+            image.d->ref.ref();
+        if (d && !d->ref.deref())
+            delete d;
+        d = image.d;
+    }
     return *this;
 }
 
diff --git a/src/gui/image/qpixmap_raster.cpp b/src/gui/image/qpixmap_raster.cpp
index 53f3559..f080687 100644
--- a/src/gui/image/qpixmap_raster.cpp
+++ b/src/gui/image/qpixmap_raster.cpp
@@ -44,6 +44,7 @@
 #include "qpixmap_raster_p.h"
 #include "qnativeimage_p.h"
 #include "qimage_p.h"
+#include "qpaintengine.h"
 
 #include "qbitmap.h"
 #include "qimage.h"
@@ -302,6 +303,13 @@ bool QRasterPixmapData::hasAlphaChannel() const
 
 QImage QRasterPixmapData::toImage() const
 {
+    if (image.paintEngine()
+        && image.paintEngine()->isActive()
+        && image.paintEngine()->paintDevice() == &image)
+    {
+        return image.copy();
+    }
+
     return image;
 }