Re: [PATCH] cherry-pick: Add an option to prepend a string to the commit message

On 06/11/2010 11:28 PM, Jeff King wrote:

On Sat, Jun 12, 2010 at 12:58:32AM -0500, Jonathan Nieder wrote:

quoted

I would be interested to hear from those who might know whether
something generic like the applypatch-msg hook could work (which is
not to say a convenient command-line option would not be handy to have
in addition to that.)

What bothers me is how specific this munging is. What if I want to
append to the message? Or put something after the subject line, but
before the commit body? Or add a pseudo-header (like signed-off-by) to
the set of pseudo-headers at the end, properly adding a newline if it is
the first such pseudo-header.

What prompted this was a large project I had checked out through 
git-svn.  I had made a number of commits to trunk, interspersed with 
other dev's work.  I needed to cherry-pick my work into a stable branch, 
but each commit needed to start with 'cherry-pick rXXX:', where XXX was 
the subversion commit number.

My solution was the following:

$ git checkout $RELEASE_BRANCH
$ export WHAT="my-subsystem:"
$ export SINCE="Jun 1 2010"
$ for i in `git log --grep="$WHAT" --oneline master --after="$SINCE" \
             | cut -d ' ' -f 1 | tac`;                                \
       do git cherry-pick $i -x                                       \
              --prepend "cherry pick r$(echo $(git log -1 $i) | perl  \
                                   -pe 's|.*/trunk@(\d+).*|\1|'): ";  \
   done

but, as you point out, I could have accomplished the same thing through 
other means.

FWIW, we can already do this kind of stuff with:

   GIT_EDITOR="sed -i 1i$prefix" git cherry-pick -e $ref

or

   git cherry-pick -n $ref&&
   sed -i 1i$prefix .git/MERGE_MSG
   GIT_EDITOR=true git commit

I'll admit the first one is not very intuitive. But it is easy to script
around the second form. For one of my examples, I would probably do:

   git cherry-pick -n $ref&&
   git log -1 --format='%s%n%ncontent between subject and body%n%b' |
   git commit -F -

I like this; it clearly hadn't occurred to me.  I can just use this 
format instead.

yours,
Bobby

The specifics aren't important, but I think you can see that the "don't
commit automatically, make a message as you like, and then use the
regular message-specifiers for commit to commit it" technique is pretty
straightforward and very flexible.

It's obviously more typing for occasional interactive use, but in that
case, why not just use "git cherry-pick -e" and use your editor?

-Peff