[PATCH] t7400: fix bogus test failure with symlinked trash

One of the tests in t7400 fails if the trash directory has a symlink anywhere in its path. E.g.:

  $ mkdir /tmp/git-test
  $ mkdir /tmp/git-test/real
  $ ln -s real /tmp/git-test/link

  $ ./t7400-submodule-basic --root=/tmp/git-test/real
  ...
  # passed all 44 test(s)

  $ ./t7400-submodule-basic --root=/tmp/git-test/link
  ...
  not ok - 41 use superproject as upstream when path is relative and no url is set there

The failing test does:

  git submodule add ../repo relative &&
  ...
  git submodule sync relative &&
  test "$(git config submodule.relative.url)" = "$submodurl/repo"

where $submodurl comes from the $TRASH_DIRECTORY the user gave us. However, git will resolve symlinks when converting the relative path into an absolute one, leading them to be textually different (even though they point to the same directory).

Fix this by asking git to canonicalize the name of the trash directory for us.

Signed-off-by: Jeff King <peff@peff.net>
---
This feels a little funny, because we are probably using the same
"convert relative to absolute" code to generate our expected value, as
well as in the test itself. So any bug in that code is likely to be
masked. But this test isn't really about checking the absolute path
code, but rather making sure that it is invoked properly.

 t/t7400-submodule-basic.sh |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)