no URL attr leads to crash when output format is cmap

[GoogleCodeExporter]

What steps will reproduce the problem?
import pydot
graph = pydot.Dot('graphname', graph_type='graph')
node_a = pydot.Node("Node A", style="filled", fillcolor="#21e1d2", 
shape="folder")
graph.add_node(node_a)

#graph.write_jpg('hu.jpeg')
#graph.write_gif('hu.gif')
#print graph.create(format="jpeg")
graph.write_cmap('hu.cmap')
print graph.create(format="cmap")
#graph.write_dot('hu.dot')

# leads to
# ========

#Traceback (most recent call last):
#  File "test_pydot2.py", line 9, in <module>
#    graph.write_cmap('hu.cmap')
#  File "build/bdist.linux-i686/egg/pydot.py", line 1602, in <lambda>
#  File "build/bdist.linux-i686/egg/pydot.py", line 1696, in write
#TypeError: argument 1 must be string or buffer, not list

Please provide any additional information below.

patch:

+++ pydot.py    2010-09-01 11:25:11.000000000 +0200
@@ -1807,5 +1807,5 @@

         os.unlink(tmp_name)

-        return stdout_output
+        return stdout_output or ''

Original issue reported on code.google.com by nicolas....@gmail.com on 1 Sep 2010 at 9:29

[GoogleCodeExporter]

Original comment by ero.carr...@gmail.com on 30 Oct 2010 at 10:59

• Changed state: Accepted
• Added labels: ****
• Removed labels: ****

[GoogleCodeExporter]

Original comment by ero.carr...@gmail.com on 31 Oct 2010 at 12:21

• Changed state: Fixed
• Added labels: ****
• Removed labels: ****