[MERGE #102747] pre_commit hook

[Ian Clatworthy]

Aaron Bentley wrote:
> John Arbash Meinel wrote:

>> I think you are misunderstanding this.

Yes I did - apologies. Nam and I discussed it on IRC shortly after my
review and we agreed it did indeed look OK.

> I agree.  The commit doesn't take effect until the branch has been updated.
> 
> But I think it's easy to misunderstand.  Perhaps CommitBuilder's commit
> method could be renamed to something like "finish_revision"?

That's a good idea I think. Rob has just provided a thoughtful response
to some other changes to CommitBuilder I had up for review. I'll include
that change in the resubmit unless there are objections to it.

FWIW, what isn't obvious to me though is whether it's better or worse to
run the pre-commit hooks before or after the commit() method. Does it
matter either way? If there are multiple places in the code where we
*could* run them, should the policy with pre-commit hooks be to do them
as early as possible or as late as possible?

Ian C.