Re: [PATCH] git-commit --amend: respect grafted parents.

Hi,

On Wed, 26 Sep 2007, Johannes Sixt wrote:

Johannes Schindelin schrieb:

quoted

On Wed, 26 Sep 2007, Johannes Sixt wrote:

quoted

This allows a poor-mans-filter-branch of the top-most commit.

Specifically, I had this history:

   --o--o--A'    <-- amended version of A
         \
          A
           \
    --o--B--M

I now wanted to "amend" M to pull in A' instead of A as its second 
parent. For various reasons I didn't want to redo the merge M again, 
in particular, it already contained the changes that were amended 
into A'. So I figured I would just install a graft that lists B and 
A' as parents of M and then do a simple git commit --amend. Alas, 
git commit looks at the real parents instead of the grafted ones, so 
the amended M' would still have A as its second parent. Here is the 
fix that picks the grafted parents instead.

I do not think that this is a "fix".

I'd really suggest that you fix it up (before the amend!) by 
installing the graft, and running git-filter-branch -1 <branch>.  
(Note: I did not test this, but it _should_ work.  If it does not, 
please let me know.)

The problem with filter-branch is that it leaves a committer date in M 
that is before A', and for this reason is not the right tool for this 
task. So I do think that this fix is necessary.

But that's easily fixed with "--env-filter 'export 
GIT_COMMITTER_DATE=$(date +%s)'" or something similar.

The reason why I insist on not putting this into --amend is that I think 
this is not really an amend, but actively a rewrite of the merge commit.  

Ciao,
Dscho