Re: Find out on which branch a commit was originally made

[lists@haller-berlin.de (Stefan Haller)]

Ævar Arnfjör? Bjarmason <avarab@gmail.com> wrote:

>     You want to do X, and you think Y is the best way of doing so.
> Instead of asking about X, you ask about Y.

Erm, not really; I explicitly mentioned Y as "a possible workaround"
only.  Anyway...

> Why do your co-workers think this is essential to the point that they
> can't get by without it? What problem are they trying to solve?

It's a common situation that you want to know why a certain piece of
code is written the way it is.  So you blame it, you eventually end up
at a certain interesting changeset, and hopefully the commit message
tells you enough about why the change was made.  If it doesn't, then it
can help a lot to know a bit more about the context of the change, i.e.
what topic it was part of.

> What Git *does* track however when you do `git merge topic` is the
> name of the `topic` branch you're merging into some other branch,
> e.g. here (from git-merge(1)):
> 
>                      A---B---C topic
>                     /         \
>                D---E---F---G---H master
> 
> Even though A B and C might have been commited on branches called
> `blah`, `bluh` and `blarghl` you'll never know. You'll just know that
> someone put them all together on a branch called `topic` and that
> someone later merged that into master in the main repository. E.g.:
> 
>     Merge: A G
>     Author: Some Guy <some-guy@example.com>
>     Date:   <....>
> 
>         Merge branch 'topic'
> 
> From there you can *infer* that A-B-C came from the topic branch,

OK, that's pretty much the same as what I had in mind.  (We're
simple-minded, so for us "original branch" and topic branch is the same
most of the time.)

The question is the same though: if I hit commit B while blaming, how do
I know what topic it was a part of?  For that, I need to find commit H
which will tell me, right?  How do I do that?

-Stefan


-- 
Stefan Haller
Berlin, Germany
http://www.haller-berlin.de/