Assertion Error when "diffing" index during cherry pick conflict.

[Agecaf]

I am trying to use gitpython to make a tool for helping in cherry-picking. The "repo.git.cherry_pick('hexsha')" command works perfectly, but, when I want to check the files with conflicts via

repo.index.diff(None)

I get the following Assertion Error;

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\git\index\util.py", line 69, in check_default_index
    return func(self, *args, **kwargs)
  File "C:\Python27\lib\site-packages\git\index\base.py", line 1197, in diff
    return super(IndexFile, self).diff(other, paths, create_patch, **kwargs)
  File "C:\Python27\lib\site-packages\git\diff.py", line 109, in diff
    index = diff_method(self.repo, proc.stdout)
  File "C:\Python27\lib\site-packages\git\diff.py", line 391, in _index_from_raw_format
    new_file, deleted_file, rename_from, rename_to, '')
  File "C:\Python27\lib\site-packages\git\diff.py", line 226, in __init__
    assert self.a_mode
AssertionError

Similarly, when comparing with head,

repo.index.diff('HEAD')

I get a slightly different error (a_mode -> b_mode);

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\git\index\util.py", line 69, in check_default_index
    return func(self, *args, **kwargs)
  File "C:\Python27\lib\site-packages\git\index\base.py", line 1189, in diff
    return other.diff(self.Index, paths, create_patch, **kwargs)
  File "C:\Python27\lib\site-packages\git\diff.py", line 109, in diff
    index = diff_method(self.repo, proc.stdout)
  File "C:\Python27\lib\site-packages\git\diff.py", line 391, in _index_from_raw_format
    new_file, deleted_file, rename_from, rename_to, '')
  File "C:\Python27\lib\site-packages\git\diff.py", line 231, in __init__
    assert self.b_mode
AssertionError

I'll be using the items with status non 0 in the index as a workaround for now (there are three per item with conflict).

Just for completeness, "diffing" works perfectly fine when not in cherry-picking conflict resolution (I tested it in the same session as the one that produced the errors).

Regards,
Agecaf

[Byron]

Thanks for the report.

Which version of GitPython are you using (possibly via print(git.__version__)) ? In case it is 1.0.1 or later, it would be great if you could create a test-repository with just enough files to help reproducing the issue. Only then a fix would be possible.

[Agecaf]

Hello, I've checked the version and it is 1.0.1.

I made a very simple merge conflict; "Hello World!" is changed into "Hola World!" and "Hello Mundo!" in two different branches (master and topic).

Here's how the bug appears (I also show what my index looks like);

>>> import git
>>> git.__version__
'1.0.1'
>>> try:
...     git.cmd.Git('.').cherry_pick('1c3cc')
... except git.GitCommandError as err:
...     print(err.status)
...     print(err.stderr)
...
1
error: could not apply 1c3cc4f... Changed Hello
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add <paths>' or 'git rm <paths>'
hint: and commit the result with 'git commit'
>>> repo = git.Repo('.')
>>> for (stage, blob) in repo.index.iter_blobs():
...     print(stage)
...     print(blob.data_stream.read())
...
2
Hello Mundo!
1
Hello World!
3
Hola World!
>>> repo.index.diff(None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\git\index\util.py", line 69, in check_default_index
    return func(self, *args, **kwargs)
  File "C:\Python27\lib\site-packages\git\index\base.py", line 1197, in diff
    return super(IndexFile, self).diff(other, paths, create_patch, **kwargs)
  File "C:\Python27\lib\site-packages\git\diff.py", line 109, in diff
    index = diff_method(self.repo, proc.stdout)
  File "C:\Python27\lib\site-packages\git\diff.py", line 391, in _index_from_raw_format
    new_file, deleted_file, rename_from, rename_to, '')
  File "C:\Python27\lib\site-packages\git\diff.py", line 226, in __init__
    assert self.a_mode
AssertionError
>>> repo.index.diff('HEAD')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\git\index\util.py", line 69, in check_default_index
    return func(self, *args, **kwargs)
  File "C:\Python27\lib\site-packages\git\index\base.py", line 1189, in diff
    return other.diff(self.Index, paths, create_patch, **kwargs)
  File "C:\Python27\lib\site-packages\git\diff.py", line 109, in diff
    index = diff_method(self.repo, proc.stdout)
  File "C:\Python27\lib\site-packages\git\diff.py", line 391, in _index_from_raw_format
    new_file, deleted_file, rename_from, rename_to, '')
  File "C:\Python27\lib\site-packages\git\diff.py", line 231, in __init__
    assert self.b_mode
AssertionError
>>> repo.head.commit.diff(None)
[<git.diff.Diff object at 0x026BB9C0>]

As you can see, diffing HEAD with the working directory does work, just not comparisons with the index (which has three copies of each file, one for the common ancestor, one for 'ours' and one for 'theirs', with different stages).

Thanks,
Agecaf

[Byron]

You can watch the development stream on youtube.

GitPython #17 [issue 323 - a buggy assertion]