IndexError when Diffing content.xml from ODT

[Brian Pitts]

Binary package hint: xmldiff

[append-first, /,
Traceback (most recent call last):
  File "/usr/bin/xmldiff", line 4, in <module>
    main.run()
  File "/usr/lib/python2.5/site-packages/xmldiff/main.py", line 256, in run
    encoding, html)
  File "/usr/lib/python2.5/site-packages/xmldiff/main.py", line 118, in process_files
    strategy.process_trees(tree1, tree2)
  File "/usr/lib/python2.5/site-packages/xmldiff/fmes.py", line 104, in process_trees
    self._formatter.end()
  File "/usr/lib/python2.5/site-packages/xmldiff/format.py", line 80, in end
    self.format_action(action)
  File "/usr/lib/python2.5/site-packages/xmldiff/format.py", line 105, in format_action
    xml_print(action[A_N2])
  File "/usr/lib/python2.5/site-packages/xmldiff/objects.py", line 180, in xml_print
    _xml_print_internal_format(node, indent, stream)
  File "/usr/lib/python2.5/site-packages/xmldiff/objects.py", line 191, in _xml_print_internal_format
    n[N_CHILDS][0][N_VALUE])
IndexError: list index out of range

[Guillaume Desmottes (cassidy)]

Got that crash too when trying to use xmldiff.

[Tom Rowlands (tom-rowlands)]

What appears to be the same bug is triggered even with very simple input. No difference is detected between:

<testfile/>

and

<testfile>
</testfile>

Faulty behaviour, possibly the same bug, is triggered whenever there is more than one element in the file, not including the XML declaration. (That comment is for clarity; formally the declaration may not be considered an element.) Consequently, the following is also considered the same as both the above by the broken xmldiff:

<?xml version="1.0" encoding="UTF-8"?>
<testfile>
</testfile>

However, the xmldiff is used to compare:

<t><q/></t>

with

<t><q></q></t>

it returns that the files are logically different and that the following is the difference:

<?xml version="1.0"?>
<xupdate:modifications xmlns:xupdate="http://www.xmldb.org/xupdate" version="1.0">
  <xupdate:append select="/" child="first()">
    <xupdate:element name="t"> </xupdate:element>
  </xupdate:append>
  <xupdate:remove select="/t[2]/q[1]"/>
  <xupdate:append select="/t[1]">
    <xupdate:element name="q"> </xupdate:element>
  </xupdate:append>
  <xupdate:remove select="/t[2]"/>
</xupdate:modifications>

[Lincoln Stoll (lstoll)]

A quick test shows this is related to python 2.6 - if xmldiff is run with python2.5 (e.g /usr/bin/python2.5 /usr/bin/xmldiff bwah) it works.