Re: [GSoC][PATCH 4/8] submodule: port submodule subcommand 'status' from shell to C

[Stefan Beller <sbeller@google.com>]

On Tue, Jul 18, 2017 at 3:32 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Stefan Beller <sbeller@google.com> writes:
>
>>> +       if (!lstat(list_item->name, &st) && !ce_match_stat(list_item, &st, 0)) {
>>> +               print_status(info, ' ', list_item->name, sub_sha1, displaypath);
>>
>> The question from the last round still stands
>> https://public-inbox.org/git/CAGZ79kb18z5zc9iu3Vv5aVZWJmoZzmwbMVpy89VC-t-ei2M+bw@mail.gmail.com/
>>
>>   I am not an expert in the diff area  and wonder how
>>   the cmd_diff_files functionality is achieved with just a stat call
>>   and then comparing it to  ce_match_stat. 'Using "dirty" ignores
>>   all changes to the work tree of submodules, only changes to the
>>   commits stored in the superproject are shown.' So I'd have
>>   expected ce->oid to be compared (is there an index entry differing,
>>   i.e. more than one stage?)
>
> ce_match_stat() calls into ce_compare_gitlink() for a 160000 entry,
> which would resolve HEAD ref there and compares ce->oid with it.

Oh in that case this should be fine, as in the original we did
"git diff-files --ignore-submodules=dirty <path>",
which did precisely that.

> But as you said, this is probably insufficient to emulate the
> original.  Shouldn't it call into run_diff_files(), which is the
> in-core way to run the equivalent of "diff-files"?

Oh, your comment in [1] was related to cmd_diff_files,
which is more complicated than run_diff_files?
run_diff_files also iterates over all cache entries.
I think we need to be looking at match_stat_with_submodule
to figure out what we need to do.

[1] https://public-inbox.org/git/xmqq60fdoyyt.fsf@gitster.mtv.corp.google.com/