backport of bugfix for #1495

git-svn-id: http://svn.osgeo.org/qgis/branches/Version-1_0@10124 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/core/qgsvectorlayer.cpp

@@ -1648,7 +1648,7 @@ int QgsVectorLayer::addIsland( const QList<QgsPoint>& ring )
     }
   }
 
-  //else, if must be contained in mCachedGeometries
+  //is the feature contained in the view extent (mCachedGeometries) ?
   QgsGeometryMap::iterator cachedIt = mCachedGeometries.find( selectedFeatureId );
   if ( cachedIt != mCachedGeometries.end() )
   {
@@ -1660,6 +1660,23 @@ int QgsVectorLayer::addIsland( const QList<QgsPoint>& ring )
     }
     return errorCode;
   }
+  else //maybe the selected feature has been moved outside the visible area and therefore is not contained in mCachedGeometries
+  {
+    QgsFeature f;
+    QgsGeometry* fGeom = 0;
+    if(featureAtId( selectedFeatureId, f, true, false ))
+    {
+      fGeom = f.geometryAndOwnership();
+      if(fGeom)
+      {
+        int errorCode = fGeom->addIsland(ring);
+        mChangedGeometries.insert( selectedFeatureId, *fGeom);
+        setModified( true, true );
+        delete fGeom;
+        return errorCode;
+      }
+    }
+  }
 
   return 6; //geometry not found
 }