fix crash when changing screen while rendering (#8328)

remove this assert since by the time the map is rendered the screen changed and might not have the same DPR.
qgis · Oct 25, 2018 · bf5537e · bf5537e
1 parent 699d848
commit bf5537e
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -690,7 +690,13 @@ QgsRectangle QgsMapCanvas::imageRect( const QImage &img, const QgsMapSettings &m
   // expects (encoding of position and size of the item)
   const QgsMapToPixel &m2p = mapSettings.mapToPixel();
   QgsPointXY topLeft = m2p.toMapCoordinates( 0, 0 );
-  Q_ASSERT( img.devicePixelRatio() == mapSettings.devicePixelRatio() );
+#ifdef QGISDEBUG
+  // do not assert this, since it might lead to crashes when changing screen while rendering
+  if ( img.devicePixelRatio() != mapSettings.devicePixelRatio() )
+  {
+    QgsLogger::warning( QStringLiteral( "The renderer map has a wrong device pixel ratio" ) );
+  }
+#endif
 #if QT_VERSION >= 0x050600
   double res = m2p.mapUnitsPerPixel() / img.devicePixelRatioF();
 #else