IndexError: list index out of range (Too big changeset?)

[kutzera@…]

How to Reproduce

While doing a GET operation on /changeset/495, Trac issued an internal error.

I think the changeset is too big. The unified diff file is about 2000 lines. Other changesets do work.

Request parameters:

{'new': u'495'}

System Information

Trac	0.11dev-r6000
Python	2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)]
setuptools	0.6c6
SQLite	3.3.4
pysqlite	2.3.2
Genshi	0.4.4
Subversion	1.4.4 (r25188)

Python Traceback

Traceback (most recent call last):
  File "c:\python25\lib\site-packages\Trac-0.11dev_r6000-py2.5.egg\trac\web\main.py", line 381, in dispatch_request
    dispatcher.dispatch(req)
  File "c:\python25\lib\site-packages\Trac-0.11dev_r6000-py2.5.egg\trac\web\main.py", line 213, in dispatch
    data, content_type)
  File "c:\python25\lib\site-packages\Trac-0.11dev_r6000-py2.5.egg\trac\web\chrome.py", line 601, in render_template
    return stream.render(method, doctype=doctype)
  File "build/bdist.macosx-10.3-fat/egg/genshi/core.py", line 154, in render
    return encode(generator, method=method, encoding=encoding)
  File "build/bdist.macosx-10.3-fat/egg/genshi/output.py", line 45, in encode
    output = u''.join(list(iterator))
  File "build/bdist.macosx-10.3-fat/egg/genshi/output.py", line 274, in __call__
    for kind, data, pos in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/output.py", line 519, in __call__
    for kind, data, pos in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/output.py", line 679, in __call__
    for kind, data, pos in chain(stream, [(None, None, None)]):
  File "build/bdist.macosx-10.3-fat/egg/genshi/output.py", line 459, in __call__
    for ev in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/core.py", line 212, in _ensure
    for event in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/core.py", line 212, in _ensure
    for event in stream:
  File "c:\python25\lib\site-packages\Trac-0.11dev_r6000-py2.5.egg\trac\web\chrome.py", line 631, in _strip_accesskeys
    for kind, data, pos in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/core.py", line 212, in _ensure
    for event in stream:
  File "c:\python25\lib\site-packages\Trac-0.11dev_r6000-py2.5.egg\trac\web\chrome.py", line 620, in _generate
    for kind, data, pos in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 252, in _include
    for event in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 322, in _match
    content = list(self._include(content, ctxt))
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 263, in _include
    for event in tmpl.generate(ctxt):
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 252, in _include
    for event in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 297, in _match
    for event in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/markup.py", line 242, in _exec
    for event in stream:
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/base.py", line 421, in _eval
    result = data.evaluate(ctxt)
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/eval.py", line 136, in evaluate
    return eval(self.code, _globals, {'data': data})
  File "C:\Python25\lib\site-packages\trac-0.11dev_r6000-py2.5.egg\trac\templates\diff_div.html", line 118, in <Expression u'block.changed.lines[idx]'>
    <th>$to_n</th><td class="r"><span>${block.changed.lines[idx]}</span>&nbsp;</td>
  File "build/bdist.macosx-10.3-fat/egg/genshi/template/eval.py", line 281, in lookup_item
    return obj[key]
IndexError: list index out of range

[Christian Boos]

Would it be possible for you to attach the diff here?

svn diff -c495

(if the code is not public, maybe it would still be possible for you to e-mail it to me?)

Also don't forget to mention the diff options you used in Trac (mode, lines of context, etc.) so that I can reproduce the issue.

[anonymous]

I posted to your email. Hope it arrived.

My diff options are:

• Side by side
• 4 lines around each change
• ignore blank lines
• ignore white spaces

[Christian Boos]

Sorry, I had the fix pending for some time but didn't commit.

Fixed in [6176].

Example diff that would trigger the bug, when viewed as a side-by-side diff with Blank lines ignored and a context of 4:

Index: thinglight.cpp
===================================================================
--- thinglight.cpp    (.../thinglight.cpp)  (revision 201)
+++ thinglight.cpp    (.../c/thinglight.cpp)        (revision 204)
@@ -99,17 +99,6 @@
 //------------------------------------------------------------------------------
 void thinglightSetIntensity(DWORD level)
 {
-/*
-       static UINT8 stuff = 0x0;
-
-       if(level == 0)
-               stuff = 0x1;
-
-       if((stuff == 0x1) && (level != 0x0))
-               stuff = 0x0;
-*/
-
     // set the current level for max
     doSetStuff((UINT8)level);
-
 }