[PATCH v2 0/3] safe.directory clean-up

Changes since v1:

 - two "extra" patches for optimization that are unnecessary have
   been dropped.
 - a patch to add test for safe.directory="." use case has been
   added. 

Recently we discussed what we should do when either the path configured in the safe.directory configuration or coming from the caller of ensure_valid_ownership() function as a result of repository discovery is not normalized and textual equality check is not sufficient. See the thread the contains

  https://lore.kernel.org/git/6d5b75a6-639d-429b-bd37-232fc6f475af@gmail.com/

Here are three patches that implement the comparison between normalized path and configuration value.

Imagine that you have a repository at /mnt/disk4/repos/frotz directory but in order to make it simpler to manage and use, you have your users use /projects/frotz to access the repository. A symlink /projects/frotz pointing at /mnt/disk4/repos/frotz directory allows you to do so.

 - The first patch normalizes the path to the directory that we
   suspect is a usable repository, before comparing it with the
   safe.directory configuration variable.  The safe.directory may
   say /mnt/disk4/repos/frotz or /mnt/disk4/repos/*, but the path to
   the repository for the users may be /mnt/disk4/repos/frotz or
   /projects/frotz, depending on where they come from and what their
   $PWD makes getcwd() to say.

 - The second patch normalizes the value of the safe.directory
   variable.  This allows safe.directory to say /projects/frotz
   or /projects/* and have them match /mnt/disk4/repos/frotz (which
   is how the first patch normalizes the repository path to).

 - The third patch only adds a test to illustrate what happens when
   the safe.directory configuration is set to ".", which was a
   plausible setting for those who run "git daemon".  The
   normalization done by the first two patches is sufficient to make
   this just work.

Junio C Hamano (3):
  safe.directory: normalize the checked path
  safe.directory: normalize the configured path
  safe.directory: setting safe.directory="." allows the "current"
    directory

 setup.c                   |  28 ++++++--
 t/t0033-safe-directory.sh | 146 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 170 insertions(+), 4 deletions(-)

Range-diff against v1:
1:  20e1160946 ! 1:  86d5c83ee7 safe.directory: normalize the checked path
    @@ t/t0033-safe-directory.sh: test_expect_success 'local clone of unowned repo acce
     +		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
     +		git config --global safe.directory "$(pwd)/repository"
     +	) &&
    -+	git -C repository/ for-each-ref >/dev/null &&
    -+	git -C repo/ for-each-ref
    ++	git -C repository for-each-ref &&
    ++	git -C repository/ for-each-ref &&
    ++	git -C repo for-each-ref &&
    ++	git -C repo/ for-each-ref &&
    ++	test_must_fail git -C repository/.git for-each-ref &&
    ++	test_must_fail git -C repository/.git/ for-each-ref &&
    ++	test_must_fail git -C repo/.git for-each-ref &&
    ++	test_must_fail git -C repo/.git/ for-each-ref
     +'
     +
     +test_expect_success SYMLINKS 'checked leading paths are normalized' '
    @@ t/t0033-safe-directory.sh: test_expect_success 'local clone of unowned repo acce
     +		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
     +		git config --global safe.directory "$(pwd)/repository/*"
     +	) &&
    -+	git -C repository/s for-each-ref >/dev/null &&
    -+	git -C repo/s for-each-ref
    ++	git -C repository/s for-each-ref &&
    ++	git -C repository/s/ for-each-ref &&
    ++	git -C repo/s for-each-ref &&
    ++	git -C repo/s/ for-each-ref &&
    ++	git -C repository/s/.git for-each-ref &&
    ++	git -C repository/s/.git/ for-each-ref &&
    ++	git -C repo/s/.git for-each-ref &&
    ++	git -C repo/s/.git/ for-each-ref
     +'
     +
      test_done
2:  06de9038b7 ! 2:  c4998076da safe.directory: normalize the configured path
    @@ setup.c: static int safe_directory_cb(const char *key, const char *value,
     
      ## t/t0033-safe-directory.sh ##
     @@ t/t0033-safe-directory.sh: test_expect_success SYMLINKS 'checked leading paths are normalized' '
    - 	git -C repo/s for-each-ref
    + 	git -C repo/s/.git/ for-each-ref
      '
      
     +test_expect_success SYMLINKS 'configured paths are normalized' '
    @@ t/t0033-safe-directory.sh: test_expect_success SYMLINKS 'checked leading paths a
     +		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
     +		git config --global safe.directory "$(pwd)/repo"
     +	) &&
    -+	git -C repository/ for-each-ref >/dev/null &&
    -+	git -C repo/ for-each-ref
    ++	git -C repository for-each-ref &&
    ++	git -C repository/ for-each-ref &&
    ++	git -C repo for-each-ref &&
    ++	git -C repo/ for-each-ref &&
    ++	test_must_fail git -C repository/.git for-each-ref &&
    ++	test_must_fail git -C repository/.git/ for-each-ref &&
    ++	test_must_fail git -C repo/.git for-each-ref &&
    ++	test_must_fail git -C repo/.git/ for-each-ref
     +'
     +
     +test_expect_success SYMLINKS 'configured leading paths are normalized' '
    @@ t/t0033-safe-directory.sh: test_expect_success SYMLINKS 'checked leading paths a
     +	git init repository/s &&
     +	ln -s repository repo &&
     +	(
    -+		cd repository &&
    ++		cd repository/s &&
     +		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
     +		test_commit sample
     +	) &&
    @@ t/t0033-safe-directory.sh: test_expect_success SYMLINKS 'checked leading paths a
     +		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
     +		git config --global safe.directory "$(pwd)/repo/*"
     +	) &&
    -+	git -C repository/s for-each-ref >/dev/null &&
    -+	git -C repo/s for-each-ref
    ++	git -C repository/s for-each-ref &&
    ++	git -C repository/s/ for-each-ref &&
    ++	git -C repository/s/.git for-each-ref &&
    ++	git -C repository/s/.git/ for-each-ref &&
    ++	git -C repo/s for-each-ref &&
    ++	git -C repo/s/ for-each-ref &&
    ++	git -C repo/s/.git for-each-ref &&
    ++	git -C repo/s/.git/ for-each-ref
     +'
     +
      test_done
-:  ---------- > 3:  ffc3f7364e safe.directory: setting safe.directory="." allows the "current" directory