git only checks ceiling directories when its search ascends to a parent
directory. A ceiling directory matching the starting directory will not
prevent git from finding a repository in the starting directory or a
parent directory. libgit2 handled the former case correctly, but
differed from git in the latter case: given a ceiling directory matching
the starting directory, but no repository at the starting directory,
libgit2 would stop the search at that point rather than finding a
repository in a parent directory.
Test case using git command-line tools:
/tmp$ git init x
Initialized empty Git repository in /tmp/x/.git/
/tmp$ cd x/
/tmp/x$ mkdir subdir
/tmp/x$ cd subdir/
/tmp/x/subdir$ GIT_CEILING_DIRECTORIES=/tmp/x git rev-parse --git-dir
fatal: Not a git repository (or any of the parent directories): .git
/tmp/x/subdir$ GIT_CEILING_DIRECTORIES=/tmp/x/subdir git rev-parse --git-dir
/tmp/x/.git
Fix the testsuite to test this case (in one case fixing a test that
depended on the current behavior), and then fix find_repo to handle this
case correctly.
In the process, simplify and document the logic in find_repo():
- Separate the concepts of "currently checking a .git directory" and
"number of iterations left before going further counts as a search"
into two separate variables, in_dot_git and min_iterations.
- Move the logic to handle in_dot_git and append /.git to the top of the
loop.
- Only search ceiling_dirs and find ceiling_offset after running out of
min_iterations; since ceiling_offset only tracks the longest matching
ceiling directory, if ceiling_dirs contained both the current
directory and a parent directory, this change makes find_repo stop the
search at the parent directory.
Untangle git_futils_mkdir from git_futils_mkdir_ext - the latter
assumes that we own everything beneath the base, as if it were
being called with a base of the repository or working directory,
and is tailored towards checkout and ensuring that there is no
bogosity beneath the base that must be cleaned up.
This is (at best) slow and (at worst) unsafe in the larger context
of a filesystem where we do not own things and cannot do things like
unlink symlinks that are in our way.
