On Wed, Mar 28, 2018 at 12:10:21PM +0200, Duy Nguyen wrote:

quoted

I think it might be clearer if a single call is given both the old and
new paths. That requires the caller of chdir() storing getcwd() before
it moves, but I don't think that should be a big deal.

The problem is switching relative paths relies on the old $CWD if I'm
not mistaken and we need  getcwd() for this. I'd love to have one
callback that says "$CWD has been switched from this path to that
path, do whatever you need to" that can be called any time, before or
after chdir(). I'll look more into it.

I think it should be OK to save getcwd() and just construct the original
path after the fact. Here's some patches which do that in a nice way.

For those just joining us, this fixes a regression that was in v2.13 (so
nothing we need to worry about as part of the 2.17-rc track).

  [1/4]: set_git_dir: die when setenv() fails
  [2/4]: add chdir-notify API
  [3/4]: set_work_tree: use chdir_notify
  [4/4]: refs: use chdir_notify to update cached relative paths

 Makefile              |  1 +
 cache.h               |  2 +-
 chdir-notify.c        | 71 +++++++++++++++++++++++++++++++++++++++++++
 chdir-notify.h        | 64 ++++++++++++++++++++++++++++++++++++++
 environment.c         | 22 ++++++++++++--
 refs/files-backend.c  |  4 +++
 refs/packed-backend.c |  3 ++
 setup.c               |  9 ++----
 t/t1501-work-tree.sh  | 12 ++++++++
 9 files changed, 178 insertions(+), 10 deletions(-)
 create mode 100644 chdir-notify.c
 create mode 100644 chdir-notify.h

-Peff