On Thu, Jan 19, 2017 at 10:54:02AM -0800, Junio C Hamano wrote:
> Stefan Hajnoczi <stefanha@redhat.com> writes:
> 
> > If the tree contains a sub-directory then git-grep(1) output contains a
> > colon character instead of a path separator:
> >
> >   $ git grep malloc v2.9.3:t
> >   v2.9.3:t:test-lib.sh:	setup_malloc_check () {
> >   $ git show v2.9.3:t:test-lib.sh
> >   fatal: Path 't:test-lib.sh' does not exist in 'v2.9.3'
> 
> I am slightly less negative on this compared to 1/2, but not by a
> big margin.  The user wanted to feed a subtree to the command,
> instead of doing the more natural
> 
>     $ git grep -e malloc v2.9.3 -- t

I find <rev>:<path> vs <rev> -- <path> confusing:

            | <rev>:<path>         | <rev> -- <path>
  ----------+----------------------+---------------------
  git grep  | OK                   | OK
  ----------+----------------------+---------------------
  git show  | OK                   | <path> ignored
  ----------+----------------------+---------------------
  git log   | no output            | OK
  ----------+----------------------+---------------------

Neither syntax always does what I expect.  If git show <rev> -- <path>
honored <path> then I could use that syntax consistently.

Sorry for going on a tangent.  Does it seem reasonable to handle <path>
in git-show(1) as a UI convenience?

> So again, "contains a colon character" is not coming from what Git
> does, but the user gave Git "a colon character" when she didn't have
> to.
> 
> Having said that, if we wanted to start ignoring what the end-user
> said in the initial input like 1/2 and 2/2 does (i.e. "this specific
> tree object" as an input), I think the approach to solve for 1/2 and
> 2/2 should be the same.  I think we should decide to do a slash
> instead of a colon, not because v2.9.3: has colon at the end and
> v2.9.3:t has colon in it, but because both of these are both bare
> tree objects.  The patches presented does not seem to base their
> decision on the actual object type but on the textual input, which
> seems wrong.

Yes, reparsing the name is ugly and I hoped to get feedback with this
RFC.  Thanks for the quick review!