Fix freeze when loading point pattern fill with distance 0

This results in a QImage with 0 extension which in turn is not acceptable for the painter which in turn results in plenty of QPainter inactive messages being thrown around.
qgis · Nov 7, 2019 · f214b2c · f214b2c
1 parent 845894b
commit f214b2c
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 3 deletions.
diff --git a/src/core/symbology/qgsfillsymbollayer.cpp b/src/core/symbology/qgsfillsymbollayer.cpp
@@ -3183,7 +3183,11 @@ void QgsPointPatternFillSymbolLayer::applyPattern( const QgsSymbolRenderContext
 
   QImage patternImage( width, height, QImage::Format_ARGB32 );
   patternImage.fill( 0 );
-
+  if ( patternImage.isNull() )
+  {
+    brush.setTextureImage( QImage() );
+    return;
+  }
   if ( mMarkerSymbol )
   {
     QPainter p( &patternImage );

diff --git a/src/core/symbology/qgssymbol.cpp b/src/core/symbology/qgssymbol.cpp
@@ -527,8 +527,7 @@ void QgsSymbol::drawPreviewIcon( QPainter *painter, QSize size, QgsRenderContext
     context->setExpressionContext( expContext );
   }
 
-  const auto constMLayers = mLayers;
-  for ( QgsSymbolLayer *layer : constMLayers )
+  for ( QgsSymbolLayer *layer : qgis::as_const( mLayers ) )
   {
     if ( !layer->enabled()  || ( customContext && !customContext->isSymbolLayerEnabled( layer ) ) )
       continue;