IndexError: string index out of range

[Remy Blank]

How to Reproduce

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

This can be reproduced on t.e.o by inserting the following table into a wiki page, and previewing the page:

||column1||||

Admittedly, this syntax is now ill-defined (with the colspan functionality from #1293), but it was legal before. At any rate, this shouldn't trigger an internal error, as it prevents rendering of the whole page.

Request parameters:

{'__FORM_TOKEN': u'2ab0ddb50d29e8ee64e76d63',
 'action': u'edit',
 'comment': u'',
 'from_editor': u'1',
 'page': u'WikiStart',
 'preview': u'Preview Page',
 'readonly': u'on',
 'scroll_bar_pos': u'0',
 'sidebyside': u'on',
 'text': u'{{{\r\n#!div style="float: right; font-size: 90%; margin: 0 2em; text-align: center"\r\n\r\n\'\'\' try out our demos! \'\'\'\r\n[[br]]\r\n[/demo-0.11 Trac 0.11 demo] \r\n[[br]]or[[br]]\r\n[/demo-0.12 Trac 0.12 demo]\r\n\r\n}}}\r\n= Welcome to the Trac Open Source Project. =\r\n\r\n||column1||||\r\n\r\nTrac is an enhanced wiki and issue tracking system for software development projects.\r\nTrac uses a minimalistic approach to web-based software project management.\r\nOur mission is to help developers write great software while staying out of\r\nthe way. Trac should impose as little as possible on a team\'s established\r\ndevelopment process and policies.\r\n\r\n\r\nIt provides an interface to [http://subversion.tigris.org/ Subversion] (or other [PluginList#VersionControlSystems version control systems]), an integrated Wiki and convenient reporting facilities. \r\n\r\nTrac allows [wiki:WikiFormatting wiki markup] in issue descriptions and commit messages, creating \r\nlinks and seamless references between bugs, tasks, changesets, files and wiki pages.  \r\nA [wiki:TracTimeline timeline] shows all current and past project events in order, \r\nmaking the acquisition of an overview of the project and tracking progress very easy.\r\nThe [wiki:TracRoadmap roadmap] shows the road ahead, listing the upcoming milestones.\r\n\r\n== Good Starting Points ==\r\n\r\n * Get started with the software:\r\n  [[span(TracGuide,title=Starting point for Trac documentation)]], \r\n  [[span(TracDownload,title=Trac is open source software\\, available for download)]],\r\n  [[span(TracFaq,title=Frequently asked questions)]], \r\n  [[span(PluginList,title=Plugins for extending Trac)]],\r\n  [[span(CookBook,title=Recipes for installing and maintaining Trac)]]\r\n * Watch it evolve:\r\n  [[span(ChangeLog,title=Recent changes between Trac releases)]],\r\n  [[span(RoadMap,title=The proverbial road ahead)]],\r\n  [[span(SeaChange,title=The long term ambitions)]]\r\n * Communicate:\r\n  \'\'\'[[span(MailingList,title=Join the mailing lists for user and developer discussions)]]\'\'\',\r\n  [[span(IrcChannel,title=Chat and discuss Trac or get support)]]\r\n * Get involved:\r\n  [[span(TracProject,title=Learn more about the project)]],\r\n  \'\'\'[[span(HowToContribute,title=Practical tips for providing useful contributions)]]\'\'\',\r\n  [[span(TracTeam,title=It\'s their fault - well not really)]],\r\n  [[span(AboutTrac,title=Links to presentation materials\\, references\\, etc.)]],\r\n  [[span(TracDev,title=Dive into the internals of Trac)]]\r\n\r\nFor a complete list of available wiki pages, see the TitleIndex.\r\n\r\n== About This Site ==\r\nThis is the TracWiki, editable by its users. This [http://c2.com/cgi/wiki?WikiWikiWeb is a feature]. \r\n\r\nHowever the site you are currently visiting tracks the actual development of the Trac project, so \'\'\'please don\'t make edits here on trac.edgewall.org simply for the sake of testing Trac\'\'\'. [[br]]\r\n\r\nInstead, if you want to test out some of the features in Trac, please use the \'\'\'[/demo-0.11 demo-0.11 site]\'\'\' or \'\'\'[/demo-0.11 demo-0.12 site]\'\'\'.\r\n\r\n== Trac Users ==\r\nAre you curious who is using Trac, or would like to list your own name, visit the TracUsers page.\r\n',
 'version': u'123'}

User Agent was: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7

System Information

Trac	0.12dev-r9030
Python	2.5.2 (r252:60911, Oct 5 2008, 19:29:17) [GCC 4.3.2]
setuptools	0.6c9
psycopg2	2.0.8
Genshi	0.6dev-r1092
Babel	0.9.4
Pygments	1.1.1dev-20091217
Subversion	1.5.1 (r32289)
Docutils	0.6
jQuery	1.3.2

Enabled Plugins

Python Traceback

Traceback (most recent call last):
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 495, in _dispatch_request
    dispatcher.dispatch(req)
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 249, in dispatch
    content_type)
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 854, in render_template
    stream.render(method, doctype=doctype, out=buffer)
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 183, in render
    return encode(generator, method=method, encoding=encoding, out=out)
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 58, in encode
    for chunk in iterator:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 339, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 826, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 670, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 771, in __call__
    for kind, data, pos in chain(stream, [(None, None, None)]):
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 586, in __call__
    for ev in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 939, in _strip_accesskeys
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 928, in _generate
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 380, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 380, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 380, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 330, in _match
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 330, in _match
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 552, in _flatten
    result = _eval_expr(data, ctxt, vars)
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 277, in _eval_expr
    retval = expr.evaluate(ctxt)
  File "build/bdist.linux-x86_64/egg/genshi/template/eval.py", line 178, in evaluate
    return eval(self.code, _globals, {'__data__': data})
  File "/tmp/.lighttpd-egg-cache-0.12-pre-multirepos/Trac-0.12dev_r9030-py2.5.egg-tmp/trac/wiki/templates/wiki_edit.html", line 136, in <Expression u'wiki_to_html(context(page.resource), page.text)'>
    ${wiki_to_html(context(page.resource), page.text)}
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1216, in format_to_html
    return HtmlFormatter(env, context, wikidom).generate(escape_newlines)
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1171, in generate
    escape_newlines)
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 960, in format
    result = re.sub(self.wikiparser.rules, self.replace, line)
  File "/usr/lib/python2.5/re.py", line 150, in sub
    return _compile(pattern, 0).sub(repl, string, count)
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 904, in replace
    replacement = self.handle_match(fullmatch)
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 900, in handle_match
    return internal_handler(match, fullmatch)
  File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 784, in _table_cell_formatter
    alignleft = self.line[end] != ' '
IndexError: string index out of range

[Christian Boos]

A bit more tricky than I thought, but should be fixed in r9050.

[Remy Blank]

Replying to cboos:

A bit more tricky than I thought,

That's what I thought as well :)

but should be fixed in r9050.

Thanks!