TypeError: argument 1 must be string or read-only buffer, not None

[Christian Boos]

How to Reproduce

While doing a POST operation on /wiki/GraphVizExample, Trac issued an internal error.

When click Preview key i'm get this error

Request parameters:

{'__FORM_TOKEN': u'07fdea90a905373de022904f',
 'action': u'edit',
 'comment': u'',
 'editrows': u'20',
 'page': u'GraphVizExample',
 'preview': u'Preview Page',
 'scroll_bar_pos': u'0',
 'text': u'{{{\r\n#!graphviz\r\n  digraph G {\r\n    rankdir = "LR"\r\n    GraphViz [ URL=GraphvizPlugin ]\r\n    Trac [ \r\n      URL="http://trac.edgewall.org/"   \r\n      fontcolor=blue\r\n    ]\r\n    GraphViz -> Trac\r\n    }\r\n}}}',
 'version': u'0'}

User Agent was: Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_4_11; en) AppleWebKit/525.18 (KHTML, like Gecko) Version/3.1.2 Safari/525.22

System Information

Trac	0.11.1
Python	2.4.4 (#2, Apr 15 2008, 23:43:20) [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)]
setuptools	0.6c9
SQLite	3.3.8
pysqlite	2.3.2
Genshi	0.5.1
Pygments	0.11.1
Subversion	1.4.2 (r22196)
jQuery:	1.2.6

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/web/main.py", line 423, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/web/main.py", line 219, in dispatch
    data, content_type)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/web/chrome.py", line 715, in render_template
    return stream.render(method, doctype=doctype)
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 179, in render
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 60, in encode
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 311, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 753, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 592, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 698, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/output.py", line 532, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/web/chrome.py", line 767, in _strip_accesskeys
    for kind, data, pos in stream:
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/web/chrome.py", line 756, in _generate
    for kind, data, pos in stream:
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 686, in _unmark
  File "build/bdist.linux-i686/egg/timingandestimationplugin/tande_filters.py", line 60, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 713, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 682, in _mark
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 686, in _unmark
  File "build/bdist.linux-i686/egg/timingandestimationplugin/tande_filters.py", line 60, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 713, in __call__
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/filters/transform.py", line 682, in _mark
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 569, in _include
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/markup.py", line 298, in _match
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/markup.py", line 298, in _match
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/markup.py", line 245, in _match
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 543, in _exec
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 533, in _eval
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 496, in _eval
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 551, in _flatten
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/path.py", line 141, in _generate
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 569, in _include
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/markup.py", line 234, in _strip
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 543, in _exec
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 533, in _eval
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 496, in _eval
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 551, in _flatten
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/core.py", line 283, in _ensure
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/path.py", line 141, in _generate
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 569, in _include
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/markup.py", line 234, in _strip
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 543, in _exec
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 520, in _eval
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/base.py", line 286, in _eval_expr
  File "/usr/lib/python2.4/site-packages/Genshi-0.5.1-py2.4-linux-i686.egg/genshi/template/eval.py", line 180, in evaluate
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/templates/wiki_edit.html", line 56, in <Expression u'wiki_to_html(context(page.resource), page.text)'>
    ${wiki_to_html(context(page.resource), page.text)}
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/util/compat.py", line 133, in newfunc
    return func_(*(args + fargs), **dict(kwargs, **fkwargs))
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 1096, in format_to_html
    return HtmlFormatter(env, context, wikidom).generate(escape_newlines)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 1055, in generate
    escape_newlines)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 833, in format
    self.handle_code_block(line)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 764, in handle_code_block
    processed = self.code_processor.process(code_text)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 179, in process
    text = self.processor(text)
  File "/usr/lib/python2.4/site-packages/Trac-0.11.1-py2.4.egg/trac/wiki/formatter.py", line 166, in _macro_processor
    text)
  File "build/bdist.linux-i686/egg/graphviz/graphviz.py", line 348, in expand_macro
  File "build/bdist.linux-i686/egg/graphviz/graphviz.py", line 534, in _launch
TypeError: argument 1 must be string or read-only buffer, not None

[Christian Boos]

It's a typo - input should have been encoded_input. No NameError exception was raised because input is also a builtin...

I should also try to build rsvg in order to test the "antialias using SVG" code path one day ;-) In the meantime, could you please check the fix?

Index: graphviz/graphviz.py
===================================================================
--- graphviz/graphviz.py        (revision 4495)
+++ graphviz/graphviz.py        (working copy)
@@ -530,7 +530,7 @@
             encoded_cmd.append(arg)
         p = subprocess.Popen(encoded_cmd, stdin=subprocess.PIPE,
                              stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        if input:
+        if encoded_input:
             p.stdin.write(encoded_input)
         p.stdin.close()
         out = p.stdout.read()

[Christian Boos]

(In [4536]) GraphvizPlugin: fix typo which went unnoticed because the missing variable name is actually a builtin (closes #3912)