[RFC 0/6] git-check-attr should work for relative paths

Currently, git-check-attr gets confused if it is passed certain types of unnormalized paths or is invoked from a non-top-level directory. For example, using the test repo created by t0003-attributes.sh, inquiring about a path that starts with "./" causes git-check-attr to emit a spurious warning:

    $ git check-attr test ./f
    [attr]notest !test
     not allowed: ./.gitattributes:1
    ./f: test: f
    $ git check-attr test ./a/i
    [attr]notest !test
     not allowed: ./.gitattributes:1
    ./a/i: test: a/i

In these cases it seems to find the right values, even including the application of macros from the top-level .gitattributes file. (My guess is that it is loading the top-level .gitattributes file twice--once as a top-level file, and once believing that it is in a subdirectory.)

Invoking git-check-attr from a subdirectory using a relative path gives incorrect answers; for example:

    $ (cd a; git check-attr test i )
    i: test: unspecified

(On the other hand, if invoked using the full path of a file, it "works":

    $ (cd a; git check-attr test a/i )
    a/i: test: a/i

.) I think that this behavior is confusing and inconsistent with other git commands. It is also inconsistent with the behavior of .gitignore, which works from subdirectories.

The patches in this series add tests demonstrating the problem, propose a possible solution, and add a couple of subcommands to test-path-utils.

I am far from confident that the solution proposed in patch 4 is correct; please see the notes in that email for discussion.

The changes to test-path-utils helped me figure out how the corresponding functions work (comments? we don't need no stinkin' comments) but they are not used anywhere. Take 'em or leave 'em.

Michael Haggerty (6):
  git-check-attr: test that no output is written to stderr
  git-check-attr: Demonstrate problems with unnormalized paths
  git-check-attr: Demonstrate problems with relative paths
  git-check-attr: Normalize paths
  test-path-utils: Add subcommand "absolute_path"
  test-path-utils: Add subcommand "prefix_path"

 builtin/check-attr.c  |   20 ++++++++++++--------
 t/t0003-attributes.sh |   29 ++++++++++++++++++++++++++---
 test-path-utils.c     |   22 ++++++++++++++++++++++
 3 files changed, 60 insertions(+), 11 deletions(-)