[GSoC][PATCH 0/4] teach git repo info to handle path keys

Hi!

The first and second patches are self-explanatory, so I will focus more on the third and fourth patches, which introduce the path-related fields to `git repo info`.

In the last discussion [1] we had on the mailing list about paths in repo info, we didn't reach a definitive conclusion, but adding both options made the most sense based on the feedback.

So in patches 3 and 4, we add both `path.<field>.absolute` and `path.<field>.relative` for `gitdir` and `commondir`. Initially, it was proposed by Ayush to use `path.absolute.<field>`, but this would break the lexicographical order of the internal field array. I tweaked it to place the variant at the end as a suffix instead.

There are still a few open questions that should be addressed by the community. I am tagging members who were involved in the previous discussions:

Justin Tobler, Lucas Seiki Oshiro, Junio, Phillip Wood, brian m. carlson, and Ayush Jha.

Apologies if I missed anyone; I included everyone who reviewed or participated in the discussions of Eslam's and Lucas's patches.

Questions:

1. Should there still be a --path-format flag?
2. Should we consider a default option?
   Currently we have path.gitdir.absolute; should we consider
   an option where a plain path.gitdir returns some default?
   If yes:
     2.1 Should we keep the default the same as rev-parse? Or
         should either relative or absolute be the default?
     2.2 When printing using --all, should the default be
         printed, or should we print both absolute and
         relative?
3. Is printing both absolute and relative in a single call
   using --all acceptable?
   If no:
     3.1 What's a better approach?

I have discussed these changes with both Justin and Lucas internally. This series is presented to gather opinions from the wider community before moving forward.

K Jayatheerth (4):
  path: add strbuf_add_path for formatting paths
  rev-parse: use strbuf_add_path for path formatting
  repo: add path.gitdir with absolute and relative suffix formatting
  repo: add path.commondir with absolute and relative suffix formatting

 Documentation/git-repo.adoc |  15 ++++++
 builtin/repo.c              |  50 ++++++++++++++++++
 builtin/rev-parse.c         | 100 ++++++++----------------------------
 path.c                      |  58 +++++++++++++++++++++
 path.h                      |  16 ++++++
 t/t1900-repo-info.sh        |  32 ++++++++++++
 6 files changed, 192 insertions(+), 79 deletions(-)