Re: git submodules implementation question

From: Uma Srinivasan <usrinivasan@twitter.com>
Date: Aug 29, 2016, 23:04 UTC
Message-ID: <CAN5XQfsg_sJbyjfdc=-e85jiCQNUqagwgh6TVOXN+NskZ7KkVw@mail.gmail.com>
In-Reply-To: <CAN5XQfty6Fshzf6kN7eXhFekU9+=VPwbzEPN1a92yVB=9nm0Vg@mail.gmail.com>

With respect to my original problem with a corrupted .git directory under the submodule directory, I am thinking of adding the following 4 lines marked with ### to is_submodule_modified() to detect the corrupted dir and die quickly instead of forking several child processes:

               strbuf_addf(&buf, "%s/.git", path);
               git_dir = read_gitfile(buf.buf);
               if (!git_dir) {
                 ### strbuf_addf(&head_ref, "%s/HEAD",buf.buf);
                 ### if (strbuf_read_file(&temp_ref, head_ref.buf,0) < 0) {
                          ### die("Corrupted .git dir in submodule %s", path);
                 ###}
                         git_dir = buf.buf;
              }

This fixes my issue but what do you think? Is this the right way to fix it? Is there a better way?

Thanks, Uma

On Mon, Aug 29, 2016 at 2:13 PM, Uma Srinivasan <usrinivasan@twitter.com> wrote:

Show 33 quoted lines

> Ok that makes sense. Thanks much.
>
> Uma
>
> On Mon, Aug 29, 2016 at 2:09 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> On Mon, Aug 29, 2016 at 2:03 PM, Uma Srinivasan <usrinivasan@twitter.com> wrote:
>>> On Mon, Aug 29, 2016 at 1:03 PM, Junio C Hamano <gitster@pobox.com> wrote:
>>>>
>>>> A top-level superproject can have a submodule bound at its "dir/"
>>>> directory, and "dir/.git" can either be a gitfile which you can read
>>>> with read_gitfile() and point into somewhere in ".git/modules/" of
>>>> the top-level superproject.  "dir/.git" can _ALSO_ be a fully valid
>>>> Git directory.  So at the top of a superproject, you could do
>>>>
>>>>         git clone $URL ./dir2
>>>>         git add dir2
>>>>
>>>> to clone an independent project into dir2 directory, and add it as a
>>>> new submodule.  The fallback is to support such a layout.
>>>>
>>> Thanks for the reply. However, in this case....
>>>
>>>       git clone $URL ./dir2
>>>       git add dir2
>>>
>>> how will "dir2" get ever get registered as a submodule?
>>
>> With a separate invocation of "git config -f .gitmodules", of course.
>> The layout to use gitfile to point into .git/modules/ is a more recent
>> invention than the submodule support itself that "git add" knows about.
>> The code needs to support both layout as well as it can, and that
>> is what the "can we read it as gitfile?  If not, that directory itself may
>> be a git repository" codepath you asked about is doing.