[U-Boot] [Patman Bug Report] Patman breaks git-log during git-rebase

[Simon Glass]

Hi Masahiro,

On 4 June 2014 04:32, Masahiro Yamada <yamada.m at jp.panasonic.com> wrote:
> Hi Simon,
>
> On Mon, 2 Jun 2014 20:28:48 -0600
> Simon Glass <sjg at chromium.org> wrote:
>
>> Hi Masahiro,
>>
>> On 2 June 2014 01:44, Masahiro Yamada <yamada.m at jp.panasonic.com> wrote:
>> > Hi Simon,
>> >
>> > I found an odd behavior of Patman.
>> >
>> > If I run Patman during "git rebase -i",
>> > Patman rewrites git-log, stripping all the Patman-tags.
>> > (I lost some important tags such as "Series-changes".)
>> >
>> > I think git-log should be read-only during Patman operation.
>> > I can't understand why Patman needs to directly edit git-log.
>> > Is this a fixable problem?
>>
>> Probably you shouldn't do that. For me patman normally complains that
>> it can't find patches to process, and stops.
>>
>> Can you give me the repeat steps? I think I have seen this before but
>> I'm not sure how to make it.
>>
>> Also, patman never edits commits. I wonder if patman is moving you to
>> the wrong commit somehow. Try 'git reflog' to find something to get
>> back to.
>
>
> Please try this procedure:

Thanks for the steps.

>
> [1] Let's start our topic branch
>
>  git  checkout -b test  master
>
>
> [2] Add some commits on the topic branch
>
> echo  a  >> README
> git add  README
> git commit
>
> Input the commit message like this:
>  ----->8-----
> Test commit 1
>
> This is log. Blah Blah.
>
> Series-to: u-boot at lists.denx.de
> Series-version: 2
> Series-changes: 2
>    - Blah Blah
> -----8<-----
>
> echo  b >> README
> git add  README
> git commit -m "Test commit 2"
>
>
> [3]  Now we have two commits on the branch. Git-log is like this
>
> git log
> commit cedf7627e215135b594cd40b87b8f4a9b80375a6
> Author: Masahiro Yamada <yamada.m at jp.panasonic.com>
> Date:   Wed Jun 4 17:15:55 2014 +0900
>
>     Test commit 2
>
> commit 74a2b72c0d4201fc478e530b886c3ab3791a703e
> Author: Masahiro Yamada <yamada.m at jp.panasonic.com>
> Date:   Wed Jun 4 17:04:57 2014 +0900
>
>     Test commit 1
>
>     This is log. Blah Blah.
>
>     Series-to: u-boot at lists.denx.de
>     Series-version: 2
>     Series-changes: 2
>       - Blah Blah
>
> [4] Run "git rebase -i"
>
> git rebase -i  master
>
>
> [5] Edit the first one
>
> e   74a2b72 test commit 1
> pick cedf762 Test commit 2
>
>
> [6]  Run  "git commit  --amend"  and  edit the git-log
>
> git commit  --amend
>
> Test commit 1
>
> This is log. Blah Blah.
> Some additional log.     <-----  Add
>
> Series-to: u-boot at lists.denx.de
> Series-version: 2
> Series-changes: 2
>   - Blah Blah
>
>
> [7] Run patman
>
> tools/patman/patman  -t  -c  1
>
>
> [8] Cansel the patman  and  check the git-log
> and you will find  Patman tags are gone!!

By cancel I guess you mean to press 'q' when it asks to send the first email?

In that case I end up on an 'undefined' branch. It doesn't have any
commits. I then need to do 'git rebase --abort' to get things back to
normal, but in that case yes I have lost my changes.

>
>
> git log
>
> commit 7bfec19aebaaefba9f7062e909fa38c071191b71
> Author: Masahiro Yamada <yamada.m at jp.panasonic.com>
> Date:   Wed Jun 4 17:04:57 2014 +0900
>
>     Test commit 1
>
>     This is log. Blah Blah.
>     Some additional log.
>
>     Signed-off-by: Masahiro Yamada <yamada.m at jp.panasonic.com>
>

If you give the -a flag it will avoid trying to apply the patches, and
the problem does not happen.

The problem is that when patman applies the patches it checks out a
new branch, uses 'git am' to apply the patches one by one, and then
tries to go back to the old branch. Since the branch is called
'undefined' these doesn't really work. It seems that 'undefined' is
created by git and is persistent after it is created. It's a bit odd
but I may be missing something.

Anyway I think I can put in a check for the 'undefined' branch and avoid this.

Regards,
Simon