Jonathan Nieder venit, vidit, dixit 09/30/2010 04:32 PM:
> Hi,
>
> Michael J Gruber wrote:
>
>> Introduce a new --parent=<commit> option for the revision walker which
>> limits the commits to those which have <commit> as one of their parents.
>
> So this lists the direct children for a given commit. Could you
> mention a use case? Why would one want to use this instead of
>
> the_commit=$(git rev-parse --verify <commit>) &&
> git rev-list --parents ... ^<commit> |
> grep -F " $the_commit"
| cut -d' ' -f1 # or such :)
>
> ?
Full disclosure: I didn't see that it can be scripted that easily,
simply because the description of "--parents" does not indicate at all
that it lists the commit along with its parents. I had the impression
that it outputs the parents only (same goes for --children.) so that
looping over the rev-list output would be required, which would have
been much slower.
As a use case, it not only tells you whether a specific commit is a fork
point, it's also a reverse of "rev-parse commit^@", so to say.
Personally, this was some exercise with the revision walker before
approaching something else there.
[It also helps with "Heck, I committed on top of a detached origin/next
yesterday, how did I tag that commit.", but there are other solutions,
of course...]
Speaking of that: It helps you "going forward(!)" from a commit that you
checked out (maybe for inspection). Just imagine trying to understand a
history by checking out versions iteratively. Say, you want to review
the last 10 revs, do a "checkout HEAD~10", then a "checkout HEAD~9" and
notice that's not quite the way to do it... (Again, there are
alternatives, of course.)
>> --- a/revision.c
>> +++ b/revision.c
>> @@ -1149,6 +1149,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
>> {
>> const char *arg = argv[0];
>> const char *optarg;
>> + unsigned char sha1[20];
>
> Could this be given narrower scope?
Sure! I expected more rough edges (and some resistance) which is why I
sent a WIP first.
Michael
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html