new file mode 100644

@@ -0,0 +1,8 @@

+graph {

+	graph [layout=fdp]

+	subgraph cluster_d2dd739afc71e4eabc8b572ae98ca5e9 {}

+	node_0831ce381fb8a3782996a1d40cf8935d

+	node_166562e3c47ae9436f911047fb660528

+	cluster_d2dd739afc71e4eabc8b572ae98ca5e9 -- node_166562e3c47ae9436f911047fb660528

+	cluster_d2dd739afc71e4eabc8b572ae98ca5e9 -- node_0831ce381fb8a3782996a1d40cf8935d

+}

@@ -325,6 +325,8 @@ class DotParser(Parser):

             if self.lookahead.type == ID:

                 id = self.lookahead.text

                 self.consume()

+                # A subgraph is also a node.

+                self.handle_node(id, {})

         if self.lookahead.type == LCURLY:

             self.consume()

             while self.lookahead.type != RCURLY:

@@ -477,6 +479,12 @@ class XDotParser(DotParser):

         try:

             pos = attrs['pos']

         except KeyError:

+            # Node without pos attribute, most likely a subgraph.  We need to

+            # create a Node object nevertheless, so that any edges to/from it

+            # don't get lost.

+            # TODO: Extract the position from subgraph > graph > bb attribute.

+            node = elements.Node(id, 0.0, 0.0, 0.0, 0.0, [], None)

+            self.node_by_name[id] = node

             return

         x, y = self.parse_node_pos(pos)