[PATCH v3 0/2] rev-parse options for absolute or relative paths

There are a bunch of different situations in which one would like to have an absolute and canonical or a relative path from Git. In many of these cases, these values are already available from git rev-parse, but some values only come in one form or another.

Many operating systems, such as macOS, lack a built-in realpath command that can canonicalize paths properly, and additionally some programming languages, like Go, currently do as well. It's therefore helpful for us to provide a generic way to request that a path is fully canonicalized before using it. Since users may wish for a relative path, we can provide one of those as well.

The primary impetus for this was Git LFS, which needs paths to be canonicalized in the same way as Git in order to function correctly. See https://github.com/git-lfs/git-lfs/issues/4012 for more details.

Changes from v2:

* Incorporate multiple missing segment support into the strbuf_realpath
  code.
* Switch some invocations to use DEFAULT_UNMODIFIED, which should not
  result in a change in behavior.
* Rebase, resolving some conflicts.

Changes from v1:

* Add a function to handle missing trailing components when
  canonicalizing paths and use it.
* Improve commit messages.
* Fix broken && chain.
* Fix situation where relative paths are not relative.

brian m. carlson (2):
  abspath: add a function to resolve paths with missing components
  rev-parse: add option for absolute or relative path formatting

 Documentation/git-rev-parse.txt |  71 +++++++++++++---------
 abspath.c                       |  33 +++++++++-
 builtin/rev-parse.c             | 104 ++++++++++++++++++++++++++++----
 cache.h                         |   2 +
 t/t1500-rev-parse.sh            |  57 ++++++++++++++++-
 5 files changed, 223 insertions(+), 44 deletions(-)