fix diagram crash (fixes #15575) (#3504)

nirvn · m-kuhn · commit 9264be89e319 · 2016-09-19T15:13:18.000+02:00
diff --git a/src/core/qgsvectorlayerdiagramprovider.cpp b/src/core/qgsvectorlayerdiagramprovider.cpp
@@ -229,13 +229,14 @@ QgsLabelFeature* QgsVectorLayerDiagramProvider::registerDiagram( QgsFeature& fea
   }
 
   const GEOSGeometry* geos_geom = nullptr;
-  QScopedPointer<QgsGeometry> preparedGeom;
+  QScopedPointer<QgsGeometry> scopedPreparedGeom;
   if ( QgsPalLabeling::geometryRequiresPreparation( geom, context, mSettings.coordinateTransform(), &extentGeom ) )
   {
-    QgsGeometry preparedGeom = QgsPalLabeling::prepareGeometry( geom, context, mSettings.coordinateTransform(), &extentGeom );
-    if ( preparedGeom.isEmpty() )
+    scopedPreparedGeom.reset( new QgsGeometry( QgsPalLabeling::prepareGeometry( geom, context, mSettings.coordinateTransform(), &extentGeom ) ) );
+    QgsGeometry* preparedGeom = scopedPreparedGeom.data();
+    if ( preparedGeom->isEmpty() )
       return nullptr;
-    geos_geom = preparedGeom.asGeos();
+    geos_geom = preparedGeom->asGeos();
   }
   else
   {

Original file line number	Diff line number	Diff line change
`@@ -229,13 +229,14 @@ QgsLabelFeature* QgsVectorLayerDiagramProvider::registerDiagram( QgsFeature& fea`
`229`	`229`	`}`
`230`	`230`
`231`	`231`	`const GEOSGeometry* geos_geom = nullptr;`
`232`		`- QScopedPointer<QgsGeometry> preparedGeom;`
	`232`	`+ QScopedPointer<QgsGeometry> scopedPreparedGeom;`
`233`	`233`	`if ( QgsPalLabeling::geometryRequiresPreparation( geom, context, mSettings.coordinateTransform(), &extentGeom ) )`
`234`	`234`	`{`
`235`		`- QgsGeometry preparedGeom = QgsPalLabeling::prepareGeometry( geom, context, mSettings.coordinateTransform(), &extentGeom );`
`236`		`- if ( preparedGeom.isEmpty() )`
	`235`	`+ scopedPreparedGeom.reset( new QgsGeometry( QgsPalLabeling::prepareGeometry( geom, context, mSettings.coordinateTransform(), &extentGeom ) ) );`
	`236`	`+ QgsGeometry* preparedGeom = scopedPreparedGeom.data();`
	`237`	`+ if ( preparedGeom->isEmpty() )`
`237`	`238`	`return nullptr;`
`238`		`- geos_geom = preparedGeom.asGeos();`
	`239`	`+ geos_geom = preparedGeom->asGeos();`
`239`	`240`	`}`
`240`	`241`	`else`
`241`	`242`	`{`