Re: BUG in fetching non-checked out submodule

>> On 03.12.20 00:06, Junio C Hamano wrote:
>>> Philippe Blain <levraiphilippeblain@gmail.com> writes:
>>>
>>>> Thanks for bisecting it. That commit wanted to fix a different bug
>>>> related to nested submodules, and the route taken was simply
>>>> reverting an earlier commit (a62387b (submodule.c: fetch in
>>>> submodules git directory instead of in worktree, 2018-11-28).
>>>>
>>>> As you discovered, it breaks other scenarios.
>>>>
>>>>>
>>>>> $ git version
>>>>> git version 2.29.2.435.g72ffeb997e
>>>>>
>>>>> $ git config --get submodule.recurse
>>>>> true
>>>
>>> I think the current situation is probably worse.
>>>
>>> As a short-term fix, we should revert 1b7ac4e6d4 until we can come
>>> up with a real fix, probably.
>>
>> Junio: This is why I originally intended to commit the test case for the
>> testsuite separated from the revert and wanted to start a discussion
>> about the actual real fix for the issue:
>> https://public-inbox.org/git/1604413399-63090-1-git-send-email-peter.kaestle@nokia.com/
>>
>> My proposal would be to revert 1b7ac4e6d4 and isolate the test case
>> "test_expect_success 'setup nested submodule fetch test' '" make it
>> "test_expect_failure" and apply it instead, until we come up with a real
>> solution.
> 
> 
> I think I have the real solution. I did some debugging and I think it
> is quite easy:
> In 'get_next_submodule', 'get_submodule_repo_for(spf->r, task->sub)'
> fails to get a repo pointer for the submodule repository, since it is
> not initialized. That
> is normal. Then we go in the "else" branch, and hit this code:
> 
> /*
> * An empty directory is normal,
> * the submodule is not initialized
> */
> if (S_ISGITLINK(ce->ce_mode) &&
> !is_empty_dir(ce->name)) {
> 
> 'is_empty_dir' receives ce->name, but the current working directory is the
> Git directory of 'middle', so clearly is_empty_dir returns false, as
> 
> /path/to/git/t/trash
> directory.t5526-fetch-submodules/B/.git/modules/middle/inner
> 
> is a non-existent path. The path that we should send is the worktree
> of inner, ie.
> the concatenation of spf->r->worktree and ce->name. This would give
> 
> /path/to/git/t/trash directory.t5526-fetch-submodules/B/middle/inner,
> 
> which is an empty directory since the inner submodule is not initialized,
> and we would not get the "Could not access submodule inner" error
> that you wanted to solve.