Dot output broken in Python 3

[ronaldoussoren]

Original report by elnuno (Bitbucket: elnuno, GitHub: elnuno).

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When asking for dot output in Python 3, only (empty) subgraphs were being rendered.

In Python 3, map returns an iterator, not a list. itergraphreport creates nodes as such an iterator which gets exhausted the first time we iterate it. Then we try to use it again.

The simplest fix is to turn nodes into a list:

#!diff

diff --git a/modulegraph/modulegraph.py b/modulegraph/modulegraph.py
--- a/modulegraph/modulegraph.py
+++ b/modulegraph/modulegraph.py
@@ -1874,5 +1874,5 @@
     def itergraphreport(self, name='G', flatpackages=()):
         # XXX: Can this be implemented using Dot()?
-        nodes = map(self.graph.describe_node, self.graph.iterdfs(self))
+        nodes = list(map(self.graph.describe_node, self.graph.iterdfs(self)))
         describe_edge = self.graph.describe_edge
         edges = deque()

[ronaldoussoren]

Original comment by Ronald Oussoren (Bitbucket: ronaldoussoren, GitHub: ronaldoussoren).

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Thanks for the patch!

[ronaldoussoren]

Original comment by Ronald Oussoren (Bitbucket: ronaldoussoren, GitHub: ronaldoussoren).

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I've committed the patch in changeset 252fb9c919d8