Fix for merge of adjacent multipolygons, ticket #2188

git-svn-id: http://svn.osgeo.org/qgis/trunk@12327 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

python/core/qgsgeometry.sip

@@ -309,5 +309,10 @@ not disjoint with existing polygons of the feature*/
       @note added in version 1.2 */
     bool deletePart( int partNum );
 
+    /**Converts single type geometry into multitype geometry
+     e.g. a polygon into a multipolygon geometry with one polygon
+    @return true in case of success and false else*/
+    bool convertToMultiType();
+
 }; // class QgsGeometry
 

src/app/qgisapp.cpp

@@ -4229,6 +4229,15 @@ QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList&
     }
   }
 
+  //convert unionGeom to a multipart geometry in case it is necessary to match the layer type
+  QGis::WkbType t = vl->wkbType();
+  bool layerIsMultiType = ( t == QGis::WKBMultiPoint || t == QGis::WKBMultiPoint25D || t == QGis::WKBMultiLineString \
+                            || t == QGis::WKBMultiLineString25D || t == QGis::WKBMultiPolygon || t == QGis::WKBMultiPoint25D );
+  if ( layerIsMultiType && !unionGeom->isMultipart() )
+  {
+    unionGeom->convertToMultiType();
+  }
+
   QApplication::restoreOverrideCursor();
   progress.setValue( featureList.size() );
   return unionGeom;

src/core/qgsgeometry.h

@@ -348,6 +348,11 @@ class CORE_EXPORT QgsGeometry
       @note added in version 1.2 */
     bool deletePart( int partNum );
 
+    /**Converts single type geometry into multitype geometry
+     e.g. a polygon into a multipolygon geometry with one polygon
+    @return true in case of success and false else*/
+    bool convertToMultiType();
+
 
   private:
     // Private variables
@@ -410,11 +415,6 @@ class CORE_EXPORT QgsGeometry
                        const GEOSCoordSequence*  old_sequence,
                        GEOSCoordSequence** new_sequence );
 
-    /**Converts single type geometry into multitype geometry
-     e.g. a polygon into a multipolygon geometry with one polygon
-    @return true in case of success and false else*/
-    bool convertToMultiType();
-
     /**Translates a single vertex by dx and dy.
      @param ptr pointer to the wkb fragment containing the vertex
     @param wkbPosition position in wkb array. Is increased automatically by the function