RFC patch, 2 partscustom format for interactive rebase todo

I'm sorry if this shows up twice. I messed up the first time.

I was recently in a situation of rebasing a topic branch with many commits by several colleagues and I thought it would be useful if I could see the author of the commit in the commit table in the rebase todo file. I wanted try to squash commits by the same author where appropriate. With the help of Matt Boeh, we figured out how to patch in custom formatting of this line, and I have been trying it out for the last couple of weeks and it seems to work pretty well.

A couple of examples:

- `git config sequence.format "%<(12,trunc)%ae %s"`
- `git config sequence.format "%s <%aN %aE>"`
- `git config sequence.format "%s%n%%n%b"`

The first one tries to conserve linespace, which is a good idea for these formats. The second one could be really long but otherwise harmless. I'm unsure what would happen if I tried to rebase with the third style unedited or uncommented. I'm wary of casually testing it. It does not seem like a good idea, and should perhaps be discouraged.

Please let me know what you think.

William Clifford (2):
  Add sequence.format to interactive rebase
  Add documentation of sequence.format to interactive rebase

 Documentation/config.txt   |  9 +++++++++
 git-rebase--interactive.sh | 14 +++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

William Clifford <mr.william.clifford@gmail.com> writes:

It should be simply forbidden. The body part may have a line that is similar enough (i.e. starting with one of the command words and then a hexadecimal string) to confuse the sequencing machinery.

Other than that safety issue, I am not fundamentally opposed to the idea.

As to the implementation in 1/2, your unconditional use of ">%h" is wrong (you would end up including the commits from the left side).

Use '%m' instead of a hardcoded '>', perhaps?

Junio C Hamano <gitster@pobox.com> writes:

Also, I do not think you want to make the prepending of "%m%h " conditional. If the user for whatever silly reason asks to use a format "%m%h %m%h %m%h", let her have that _after_ the "%m%h " the machinery needs to operate, i.e. "%m%h %m%h %m%h %m%h". It is far easier to explain to the users and you can lose three lines from the second patch.

Thanks! I've set it up just this way and it seems to work fine.

It turns out the formatted string is processed by the shell `read` later on, which happens to ignore everything after the first line, so it seems like it should be safe. But doing something explicit about it seems like a good idea in this case. I will see about actually reading in additional lines and raising an error, but it occurs to me that if I can read in the additional lines, I could also insert them as comments, and then it should be as safe as any of the other comments inserted in the rebase todo. In any case I will look into it and prepare another patch.

On Tue, Sep 9, 2014 at 10:07 AM, Junio C Hamano <gitster@pobox.com> wrote:

William Clifford <mr.william.clifford@gmail.com> writes:

;-)