Re: [PATCH v2 0/3] submodule: port subcommand add from shell to C

> Hello all,
> 
> This is the v2 of the patch with the same title, delivered more than a
> month ago as a part of my GSoC. Link to v1:
> https://lore.kernel.org/git/20200824090359.403944-1-shouryashukla.oo@gmail.com/

> The changelog is as follows:
> 
>     1. Introduce PATCH[1/3](dir: change the scope of function
>        'directory_exists_in_index()', 2020-10-06). This was done since
>        the above mentioned function will be used in the patch that
>        follows.
> 
>     2. There are multiple changes in this commit:
> 
>             A. Improve the part which checks if the 'path' given as
>                argument exists or not. Implementing Kaartic's
>                suggestions on the patch, I had to make sure that the
>                case for checking if the path has tracked contents or
>                not also works.
> 
>             B. Also, wrap the aforementioned segment in a function
>                since it became very long. The function is called
>                'check_sm_exists()'.
> 
>             C. Also, use the function 'is_nonbare_repository_dir()'
>                instead of 'is_directory()' when trying to resolve
>                gitlink.
> 
>             D. Append keyword 'fatal' in front of the expected output of
>                test t7400.6 since the command die()s out in case of
>                absence of commits in a submodule.
> 
>             E. Remove the extra `#include "dir.h"` from
>                'submodule--helper.c'.
> 
>     3. Introduce PATCH[3/3] (t7400: add test to check 'submodule add'
>        for tracked paths, 2020-10-07). Kaartic pointed out that a test
>        for path with tracked contents did not exist and hence it was
>        necessary to write one. Therefore, this commit introduces a new
>        test 't7400.18: submodule add to path with tracked contents
>        fails'.