Franck Pommereau

fixed unexpected None value for stderr in plugin gv

......@@ -141,7 +141,7 @@ class Graph (Cluster) :
if not debug :
os.unlink(outfile.name)
if dot.returncode != 0 :
if stdout.strip() + stderr.strip() :
if (stdout or "").strip() + (stderr or "").strip() :
stdout = "\n*** Original error message follows ***\n " + stdout
raise IOError("%s exited with status %s%s"
% (engine, dot.returncode, stdout))
......