Re: [long] worktree setup cases

On Thu, Oct 21, 2010 at 2:07 AM, Jonathan Nieder [off-list ref] wrote:

quoted

So there are 2^5 = 32 cases in total. Let's look at them one by
one.

Thanks!  To summarize (and make sure I understand correctly):
anything not following the below rules is a bug, yes?

Let's see.

A. Weird cases.

 - using a .git file is just like setting GIT_DIR;

Yes, except that GIT_DIR can be detected early when cwd has not been
moved. When .git is found a file, cwd could have been changed.

B. Repository search.

 - if GIT_DIR was set explicitly, GIT_WORK_TREE defaults to
  "." (for legacy reasons).

Correct.

 - otherwise, if original cwd was under repository, it will not
  prompt a search for work tree, even if the repo happens
  to be named ".git" or core.bare is false.  That is, in
  this case, GIT_WORK_TREE defaults to unset.

What do you mean by "under repository"? If the repo is /tmp/git/.git,
then cwd is at /tmp/git/.git?

 - otherwise, if original cwd was under a directory containing
  repository as ".git", GIT_WORK_TREE defaults to that
  directory (i.e., parent to .git dir).

Yes.

 - otherwise, there is no repository.  GIT_DIR is unset,
  GIT_WORK_TREE defaults to unset.

- Otherwise, move up one dir and repeat?

C. Working directory and prefix

 - if GIT_WORK_TREE is still unset after repository search,
  stay in the original cwd, prefix = NULL.

if GIT_WORK_TREE and core.worktree are still unset, we get a bare repo
here (or force it to be a bare repo), so yes, cwd should stay in
original cwd and prefix = NULL.

 - if original cwd is inside worktree, chdir to toplevel,
  prefix = path to original cwd.

Yes.

 - otherwise, stay in the original cwd, prefix = NULL.

I'm not really happy with this, which is why I wrote the
--cwd-to-worktree and --worktree-to-cwd patch. But this should be
enough for full-tree operations to work, so yes.

D. User-supplied relative paths.

 - path in .git file is relative to containing directory
 - path in GIT_DIR is relative to original cwd
 - paths in GIT_WORK_TREE and core.worktree are relative to
  $GIT_DIR

I think $GIT_WORK_TREE is relative to original cwd. Yes, core.worktree
should be relative to $GIT_DIR.

 - paths passed to git commands are generally relative to
  original cwd

And filename output should also be relative to original cwd (except a
few special, like diff output).

E. Internally used relative paths.

 - all paths are relative to current cwd.

Yes.
-- 
Duy