[raster] fix raster blending (cherry-pick 93c59f4)

qgis · May 17, 2017 · 14a8df4 · 14a8df4
1 parent 126cf5f
commit 14a8df4
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/core/raster/qgsrasterdrawer.cpp b/src/core/raster/qgsrasterdrawer.cpp
@@ -99,7 +99,10 @@ void QgsRasterDrawer::draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsM
 
     delete block;
 
-    p->setCompositionMode( QPainter::CompositionMode_SourceOver );  // go back to the default composition mode
+    if ( feedback && feedback->renderPartialOutput() )
+    {
+      p->setCompositionMode( QPainter::CompositionMode_SourceOver );  // go back to the default composition mode
+    }
 
     // ok this does not matter much anyway as the tile size quite big so most of the time
     // there would be just one tile for the whole display area, but it won't hurt...