Fix bug in PropertyMap.get_array() for edge properties

The reserved size for the array was set to g.num_edges(), but it should
be set to the maximum edge index + 1, since some edges might have been
deleted.

src/graph/graph_bind.cc

@@ -366,6 +366,7 @@ BOOST_PYTHON_MODULE(libgraph_tool_core)
         .def("ClearEdges", &GraphInterface::ClearEdges)
         .def("GetVertexIndex", &GraphInterface::GetVertexIndex)
         .def("GetEdgeIndex", &GraphInterface::GetEdgeIndex)
+        .def("GetMaxEdgeIndex", &GraphInterface::GetMaxEdgeIndex)
         .def("GetGraphIndex", &GraphInterface::GetGraphIndex)
         .def("CopyVertexProperty", &GraphInterface::CopyVertexProperty)
         .def("CopyEdgeProperty", &GraphInterface::CopyEdgeProperty);

src/graph_tool/core.py

@@ -185,7 +185,7 @@ class PropertyMap(object):
         if self.__key_type == 'v':
             n = self.__g().num_vertices()
         elif self.__key_type == 'e':
-            n = self.__g().num_edges()
+            n = self.__g()._Graph__graph.GetMaxEdgeIndex() + 1
         else:
             n = 1
         self.__g().pop_filter(edge=True, vertex=True)