Restructured Text parsing - problem with leading spaces before a heading

[andre@…]

To reproduce the problem:

Create a new Wiki page, define Restructured Text formatting, then add a ReST heading in the normal manner, but with one or more leading spaces. Hit 'save', or 'preview'.

Trac then issues the following error, and a traceback.

Apologies in advance if this is a false alarm - I know it's bad formatting as far as docutils is concerned. But shouldn't Trac catch the exception gracefully, rather than dumping a traceback?

Here is the error that's produced:

Trac detected an internal error:

:3: (SEVERE/4) Unexpected section title.

Here is the traceback that's produced:

Traceback (most recent call last):
  File "/usr/local/lib/python2.3/site-packages/trac/core.py", line 475, in cgi_start
    real_cgi_start()
  File "/usr/local/lib/python2.3/site-packages/trac/core.py", line 470, in real_cgi_start
    dispatch_request(path_info, args, req, env, database)
  File "/usr/local/lib/python2.3/site-packages/trac/core.py", line 380, in dispatch_request
    module.run()
  File "/usr/local/lib/python2.3/site-packages/trac/Module.py", line 41, in run
    self.render()
  File "/usr/local/lib/python2.3/site-packages/trac/Wiki.py", line 766, in render
    Formatter(self.req.hdf, self.env).format(self.page.text, out)
  File "/usr/local/lib/python2.3/site-packages/trac/Wiki.py", line 493, in format
    self.handle_code_block(line)
  File "/usr/local/lib/python2.3/site-packages/trac/Wiki.py", line 454, in handle_code_block
    self.out.write(self.code_processor(self.hdf, self.code_text, self.env))
  File "/usr/local/lib/python2.3/site-packages/trac/wikimacros/rst.py", line 142, in execute
    html = publish_string(text, writer_name = 'html', parser = _parser)
  File "/usr/local/lib/python2.3/site-packages/docutils/core.py", line 336, in publish_string
    return pub.publish(enable_exit=enable_exit)
  File "/usr/local/lib/python2.3/site-packages/docutils/core.py", line 168, in publish
    document = self.reader.read(self.source, self.parser, self.settings)
  File "/usr/local/lib/python2.3/site-packages/docutils/readers/__init__.py", line 65, in read
    self.parse()
  File "/usr/local/lib/python2.3/site-packages/docutils/readers/__init__.py", line 71, in parse
    self.parser.parse(self.input, document)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/__init__.py", line 122, in parse
    self.statemachine.run(inputlines, document, inliner=self.inliner)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 170, in run
    input_source=document['source'])
  File "/usr/local/lib/python2.3/site-packages/docutils/statemachine.py", line 232, in run
    context, next_state, result = self.check_line(
  File "/usr/local/lib/python2.3/site-packages/docutils/statemachine.py", line 416, in check_line
    return method(match, context, next_state)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 1236, in indent
    blockquote, messages = self.block_quote(indented, line_offset)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 1247, in block_quote
    self.nested_parse(blockquote_lines, line_offset, blockquote)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 273, in nested_parse
    node=node, match_titles=match_titles)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 202, in run
    results = StateMachineWS.run(self, input_lines, input_offset)
  File "/usr/local/lib/python2.3/site-packages/docutils/statemachine.py", line 232, in run
    context, next_state, result = self.check_line(
  File "/usr/local/lib/python2.3/site-packages/docutils/statemachine.py", line 416, in check_line
    return method(match, context, next_state)
  File "/usr/local/lib/python2.3/site-packages/docutils/parsers/rst/states.py", line 2619, in underline
    nodes.literal_block(blocktext, blocktext), line=lineno)
  File "/usr/local/lib/python2.3/site-packages/docutils/utils.py", line 225, in severe
    return self.system_message(4, *args, **kwargs)
  File "/usr/local/lib/python2.3/site-packages/docutils/utils.py", line 184, in system_message
    raise SystemMessage(msg)
SystemMessage: :3: (SEVERE/4) Unexpected section title.

heading 1
=========

[daniel]

I believe it is a correct rest error, although a nicer error output would be nice.

[daniel]

Fixed in [826].