Re: [wishlist?] make submodule commands robust to having non-submodule Subprojects

From: Stefan Beller <sbeller@google.com>
Date: Sep 15, 2016, 18:15 UTC
Message-ID: <CAGZ79kbYEqbr0h_0U=Ed-NRrsjb4XmznL8C45gTyJCVx+X-LTQ@mail.gmail.com>
In-Reply-To: <xmqqwpidniry.fsf@gitster.mtv.corp.google.com>

On Thu, Sep 15, 2016 at 11:02 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 7 quoted lines

> I think that is a more pressing thing to address.  Once we make it
> easier for the user to bring a half-initialized submodule properly
> into the world view of the submodule subsystem, we would have to
> worry about the reported failure case even less and you do not need
> to pile on workaround options to let things continue in a state that
> is half-broken (that is, in a state that is perfectly sane to the
> core layer, but is not liked by the submodule layer).

Heh, I see.

    When searching around the net, some people use half
    initialized submodules intentionally, e.g. I'll store some private keys in
    sub and I publish the superproject asking for collaborators to my new shiny
    webbased thing. The submodule containing the private keys never leaves
    my hard drive, hence no .gitmodules entry is necessary.

Not sure I agree with such a setup, but people use it.

So how about this fictional work flow:

         $ git init top
         $ cd top
         $ git commit --allow-empty -m 'initial in top'
         $ git init sub
         $ git -C sub commit --allow-empty -m 'initial in sub'
         $ git add sub
        You added a gitlink, but no corresponding entry in
        .gitmodules is found. This is fine for gits core functionality, but
        the submodule command gets confused by this unless you add 'sub'
        to your .gitmodules via `git submodule add --already-in-tree \
        --reuse-submodules-origin-as-URL sub`. Alternatively you can make this
        message disappear by configuring advice.gitlinkPitfalls.

         $ git submodule
         ... similar advice goes here...
         fatal: no submodule mapping found in .gitmodules for path 'sub'

         $ git submodule add --fixup-modules-file ./sub sub
         Adding .gitmodule entry only for `sub` to use `git -C remote
show origin` as URL.

         # user is happy now.