Confused on git commit tree about Lib/datetime.py

[Thomas Jollans]

On 01/08/18 05:16, Jeffrey Zhang wrote:
> I found a interesting issue when checking the Lib/datetime.py
> implementation in python3
>
> This patch is introduced by cf86e368ebd17e10f68306ebad314eea31daaa1e [0].
> But if you
> check the github page[0], or using git tag --contains, you will find v2.7.x
> includes this commit too.
>
> $ git tag --contains cf86e368ebd17e10f68306ebad314eea31daaa1e
> 3.2
> v2.7.10
> v2.7.10rc1
> v2.7.11
> v2.7.11rc1
> ...
>
> whereas, if you check the v2.7.x code base, nothing is found
>
> $ git log v2.7.4 -- Lib/datetime.py
> <nothing here>
>
> I guess it maybe a git tool bug, or the commit tree is messed up. Is there
> any guys could explain this
> situation?
>
> [0]
> https://github.com/python/cpython/commit/cf86e368ebd17e10f68306ebad314eea31daaa1e
>
There are some crazy merges in the repository history, that are easy to 
see with gitk (and not so easy to see with github or the command-line 
porcelain)

In this case, it appears that d26b658f1433a28b611906c078f47bc804a63dd1, 
in the mercurial days, cherry-picked a patch from the 3.2 branch at 
f8b9dfd9a1a3d611d43e3c3ef8031fed96c8dd25.

I don't know why the git tools don't find this by themselves. I suppose 
this is a quirk of the hg-git transition and the different ways hg and 
git have of doing things.

-- Thomas