Re: [PATCH] Drop some dashes from built-in invocations in scripts

On 8/7/17, Junio C Hamano [off-list ref] wrote:

Just to avoid possible confusion, the above is not to say "once it
is decided, you are not allowed to bring fresh arguments to the
discussion".  As Peff said [*2*] in that old discussion thread, the
circumstances may have changed over 9 years, and it may benefit to
revisit some old decisions.

So in that sense, I do not mind somebody makes a fresh proposal,
which would probably be similar to what I did back then in [*3*],
which is at the beginning of that old thread.  But I do not think I
would be doing so myself, and I suspect that I would not be very
supportive for such a proposal, because my gut feeling is that the
upside is not big enough compared to downsides.

The obvious upside is that you do not have to have many built-in
commands on the filesystem, either as a hardlink, a copy, or a
symbolic link.  But we will be breaking people's scripts by breaking
the 11-year old promise that we will keep their "git-foo" working as
long as they prepend $GIT_EXEC_PATH to their $PATH we we did so.
Another downside is that we now will expose which subcommands are
built-in and which are not, which is unnecessarily implementation
detail we'd want end-users to rely on.

The "'git co' may stop working" I mentioned in my previous message
is not counted as a downside---if the upside is large enough, I
think that "we respawn git-foo as dashed built-in when running an
alias that expands to 'foo'" can be fixed to respawn "git foo"
instead of "git-foo".  But there may be other downside that we may
not be able to fix, and I suspect that "we'd be breaking the 11-year
old promise" is something we would not be able to fix.  That is why
I doubt that I would be advocating the removal of "git-foo" from the
filesystem myself.

Thanks for the history and explanation, Junio. I agree with your analysis.

I didn't know that git aliases invoke the `git-foo` path for built-ins
(I don't use them much myself, so didn't notice).

I also didn't know that it was supported to add GIT_EXEC_DIR to your
PATH to be able to call `git-foo`. I generally think of /libexec as
implementation-specific executables that a tool may call internally
(in that sense, whether or not the commands are built-ins would remain
an implementation-detail).

However, I still think the patch should be applied for
self-consistency at least (git-submodule.sh currently calls both `git
rev-parse` and `git-rev-parse`). Also, based on Johannes' reply, it
may still be useful for git-for-windows.

[References]

*1*
https://public-inbox.org/git/alpine.LFD.1.10.0808261114070.3363@nehalem.linux-foundation.org/

*2*
https://public-inbox.org/git/20080826145719.GB5046@coredump.intra.peff.net/

*3* https://public-inbox.org/git/7vprnzt7d5.fsf@gitster.siamese.dyndns.org/