Fix crash when trying to insert geometry into collection with bad index

src/core/geometry/qgsgeometrycollection.cpp

@@ -128,6 +128,8 @@ bool QgsGeometryCollection::insertGeometry( QgsAbstractGeometry *g, int index )
     return false;
   }
 
+  index = std::min( mGeometries.count(), index );
+
   mGeometries.insert( index, g );
   clearCache(); //set bounding box invalid
   return true;