Fix crash in QgsGeometry::unaryUnion with empty geometries

nyalldawson · nyalldawson · commit b61641dc72b1 · 2016-07-14T08:24:47.000+10:00
diff --git a/src/core/geometry/qgsgeometry.cpp b/src/core/geometry/qgsgeometry.cpp
@@ -1618,7 +1618,7 @@ QgsGeometry *QgsGeometry::unaryUnion( const QList<QgsGeometry*> &geometryList )
   QList<QgsGeometry*>::const_iterator it = geometryList.constBegin();
   for ( ; it != geometryList.constEnd(); ++it )
   {
-    if ( *it )
+    if ( *it && !(( *it )->isEmpty() ) )
     {
       geomV2List.append(( *it )->geometry() );
     }
diff --git a/tests/src/core/testqgsgeometry.cpp b/tests/src/core/testqgsgeometry.cpp
@@ -90,6 +90,8 @@ class TestQgsGeometry : public QObject
     void bufferCheck();
     void smoothCheck();
 
+    void unaryUnion();
+
     void dataStream();
 
     void exportToGeoJSON();
@@ -3256,6 +3258,20 @@ void TestQgsGeometry::smoothCheck()
   QVERIFY( QgsGeometry::compare( multipoly, expectedMultiPoly ) );
 }
 
+void TestQgsGeometry::unaryUnion()
+{
+  //test QgsGeometry::unaryUnion with null geometry
+  QString wkt1 = "Polygon ((0 0, 10 0, 10 10, 0 10, 0 0 ))";
+  QString wkt2 = "Polygon ((2 2, 4 2, 4 4, 2 4, 2 2))";
+  QScopedPointer< QgsGeometry > geom1( QgsGeometry::fromWkt( wkt1 ) );
+  QScopedPointer< QgsGeometry > geom2( QgsGeometry::fromWkt( wkt2 ) );
+  QScopedPointer< QgsGeometry > empty( new QgsGeometry() );
+  QList< QgsGeometry* > list;
+  list << geom1.data() << empty.data() << geom2.data();
+
+  QScopedPointer< QgsGeometry > result( QgsGeometry::unaryUnion( list ) );
+}
+
 void TestQgsGeometry::dataStream()
 {
   QString wkt = "Point (40 50)";

Original file line number	Diff line number	Diff line change
`@@ -1618,7 +1618,7 @@ QgsGeometry QgsGeometry::unaryUnion( const QList<QgsGeometry> &geometryList )`
`1618`	`1618`	`QList<QgsGeometry*>::const_iterator it = geometryList.constBegin();`
`1619`	`1619`	`for ( ; it != geometryList.constEnd(); ++it )`
`1620`	`1620`	`{`
`1621`		`- if ( *it )`
	`1621`	`+ if ( it && !(( it )->isEmpty() ) )`
`1622`	`1622`	`{`
`1623`	`1623`	`geomV2List.append(( *it )->geometry() );`
`1624`	`1624`	`}`