Hi,
On Thu, Sep 15, 2016 at 03:28:21PM -0700, Stefan Beller wrote:
> On Thu, Sep 15, 2016 at 3:08 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote:
> > Brandon Williams <bmwill@xxxxxxxxxx> writes:
> >
> >> You're right that seems like the best course of action and it already falls
> >> inline with what I did with a first patch to ls-files to support submodules.
> >> In that patch I did exactly as you suggest and pass in the prefix to the
> >> submodule and make the child responsible for prepending the prefix to all of
> >> its output. This way we can simply pass through the whole pathspec (as apposed
> >> to my original idea of stripping the prefix off the pathspec prior to passing
> >> it to the child...which can get complicated with wild characters) to the
> >> childprocess and when checking if a file matches the pathspec we can check if
> >> the prefix + file path matches.
> >
> > That's brilliant. A few observations.
> >
> > * With that change to tell the command that is spawned in a
> > submodule directory where the submodule repository is in the
> > context of the top-level superproject _and_ require it to take a
> > pathspec as relative to the top-level superproject, you no longer
> > worry about having to find where to cut the pathspec given at the
> > top-level to adjust it for the submodule's context. That may
> > simplify things.
>
> I wonder how this plays together with the prefix in the superproject, e.g.
>
> cd super/unrelated-path
> # when invoking a git command the internal prefix is "unrelated-path/"
> git ls-files ../submodule-*
> # a submodule in submodule-A would be run in submodule-A
> # with a superproject prefix of super/ ? but additionally we nned
> to know we're
> # not at the root of the superproject.
Do we need to know that? The internal prefix is internal to each
repository and can be treated as such. I would expect that the prefix is
only prefixed when needed. E.g. when we display output to the user,
match files, ...
How about "../submodule-A" as the submodule prefix in the situation you
describe? The wildcard would be resolved by the superproject since the
directory is still in its domain.
I would think of the submodule prefix as the path relative to the
command that started everything. E.g. if we have a tree like this:
*--subA
/
super *--subB--subsubB
\
*--dirC
where subA, subB and subsubB are submodules and dirC is just a
directory inside super.
We would get the following prefixes when issuing a command in dirC that
has a pathspec for subsubB:
subB: ../subB
subsubB: ../subB/subsubB
An interesting case is when we issue a command in subA:
super: ..
subB: ../subB
subsubB: ../subB/subsubB
A rule for the prefix option could be: Always specified when crossing a
repository boundary with the pathspec (including upwards).
I have not completely thought this through though so just take this as
some food for thought. Since I am not sure what Junio's rationale behind
making the prefix relative to the toplevel superproject was, but I guess
finding it could be a challenge in some situations. I.e. is the
repository in home directory tracking all the dot-files really the
superproject or was it that other one I found before?
> > So we may have to rethink what this option name should be. "You
> > are running in a repository that is used as a submodule in a
> > larger context, which has the submodule at this path" is what the
> > option tells the command; if any existing command already has
> > such an option, we should use it. If we are inventing one,
> > perhaps "--submodule-path" (I didn't check if there are existing
> > options that sound similar to it and mean completely different
> > things, in which case that name is not usable)?
>
> Would it make sense to add the '--submodule-path' to a more generic
> part of the code? It's not just ls-files/grep that have to solve exactly this
> problem. Up to now we just did not go for those commands, though.
Yes I think so, since it should also handle starting from a submodule
with a pathspec to the superproject or other submodule. In case we
go with my above suggestion I would suggest a more generic name since
the option could also be passed to processes handling the superproject.
E.g. something like --module-prefix or --repository-prefix comes to my
mind, not checked though.
Cheers Heiko