[PATCH v3 0/3] Multiple worktrees vs. submodules fixes

After discussions I came to basically same as v1.

* Resubmitting the 2 patches which have not been taken to worktrees reroll -
  they fix visible issue. Mostly unchanged except small cleanup in test.
* Added GIT_COMMON_DIR to local_repo_env. While it is obviously a right
  thing, I wasn't able to observe any change in behavior.

Max Kirillov (3):
  submodule refactor: use git_path_submodule() in add_submodule_odb()
  path: implement common_dir handling in git_path_submodule()
  Add GIT_COMMON_DIR to local_repo_env

 cache.h                          |  1 +
 environment.c                    |  1 +
 path.c                           | 24 ++++++++++++++++++++----
 setup.c                          | 17 ++++++++++++-----
 submodule.c                      | 28 ++++++++++------------------
 t/t7410-submodule-checkout-to.sh | 10 ++++++++++
 6 files changed, 54 insertions(+), 27 deletions(-)