Crash in qconflicts when there is conflict in non-versioned file (TypeError: argument 1 of PyQt4.QtCore.QVariant() has an invalid type)

[Philip Peitsch]

A conflict that occurs when attempting to remove a non-empty folder with no versioned children causes the qconflicts dialog to crash. I did check this with 1.1.1 and found it was still occurring.

To reproduce this bug, perform the following steps:

mkdir repo
cd repo

mkdir co1
pushd co1
bzr init
mkdir empty
bzr add
bzr commit -m "Added empty folder"
popd

bzr branch co1 co2

pushd co1
bzr rm empty
bzr commit -m "Removed empty folder"
popd

pushd co2
pushd empty
echo hi > something.txt
popd
bzr merge ../co1
bzr qconflicts # Crashes at this point
popd

Stack trace is:
bzr: ERROR: exceptions.TypeError: argument 1 of PyQt4.QtCore.QVariant() has an invalid type

Traceback (most recent call last):
  File "C:/Program Files/Bazaar/plugins\qbzr\lib\conflicts.py", line 171, in load
TypeError: argument 1 of PyQt4.QtCore.QVariant() has an invalid type

bzr 2.2.1 on python 2.6.4 (win32)
arguments: ['bzr', 'qconflicts']
encoding: 'cp1252', fsenc: 'mbcs', lang: None
plugins:
  bzrtools C:\Program Files\Bazaar\plugins\bzrtools [2.2.0]
  colo C:\Program Files\Bazaar\plugins\colo [0.1.0]
  directory_aliases C:\Source\Bazaar\bzr\directory_aliases [2.2.1]
  explorer C:\Program Files\Bazaar\plugins\explorer [1.1.1]
  fastimport C:\Program Files\Bazaar\plugins\fastimport [0.9.0dev]
  launchpad C:\Program Files\Bazaar\plugins\launchpad [2.2.1]
  loom C:\Program Files\Bazaar\plugins\loom [2.2.1dev]
  netrc_credential_store C:\Program Files\Bazaar\plugins\netrc_credential_store [2.2.1]
  news_merge C:\Program Files\Bazaar\plugins\news_merge [2.2.1]
  pipeline C:\Program Files\Bazaar\plugins\pipeline [unknown]
  qbzr C:\Program Files\Bazaar\plugins\qbzr [0.19.2]
  rewrite C:\Program Files\Bazaar\plugins\rewrite [0.6.1]
  svn C:\Program Files\Bazaar\plugins\svn [1.0.4]
  upload C:\Program Files\Bazaar\plugins\upload [1.0.0dev]
  xmloutput C:\Program Files\Bazaar\plugins\xmloutput [0.8.6]

[Nicholas Kazouris (nkazouris)]

This happens because conflict.file_id in file conflicts.py line 171 is None. If this line is changed to:

item.setData(0, QtCore.Qt.UserRole, QtCore.QVariant(conflict.file_id or ''))

this exception is not thrown, the QConflict dialog opens and the conflict can be resolved. Unfortunately, I don't know what other side effects this change may have, since I don't know Python yet :) or QBzr internals.

Tested with QBzr 0.19.3 and bzrlib 2.2.1

[Alexander Belchenko (bialix)]

Thank you for your report and analysis. I'll fix it.

[Alexander Belchenko (bialix)]

Due the big amount of duplicates the bugfix should be ported to all supported series.

[Alexander Belchenko (bialix)]

It seems this bug has very old roots.

[Alexander Belchenko (bialix)]

But maybe old Qt/PyQt was more tolerant to attempts of storing None in QVariant.

[Alexander Belchenko (bialix)]

I haven't seen any duplicate bug report mentioned qbzr 0.18.x. So I don't plan to apply the patch to that series. If you really need it fixed I'll be able to do so, please say so.