[PATCH 4/4] worktree: retire special-case normalization of main worktree path

[Eric Sunshine <sunshine@sunshineco.com>]

In order for "git-worktree list" to present consistent results,
get_main_worktree() performs manual normalization on the repository
path (returned by get_common_dir()) after passing it through
strbuf_add_absolute_path(). In particular, it cleans up the path for
three distinct cases when the current working directory is (1) the main
worktree, (2) the .git/ subdirectory, or (3) a bare repository.

The need for such special-cases is a direct consequence of employing
strbuf_add_absolute_path() which, for the sake of efficiency, doesn't
bother normalizing the path (such as folding out redundant path
components) after making it absolute. Lack of normalization is not
typically a problem since redundant path elements make no difference
when working with paths at the filesystem level. However, when preparing
paths for presentation, possible redundant path components make it
difficult to ensure consistency.

Eliminate the need for these special cases by instead making the path
absolute via strbuf_add_real_path() which normalizes the path for us.
Once normalized, the only case we need to handle manually is converting
it to the path of the main worktree by stripping the "/.git" suffix.
This stripping of the "/.git" suffix is a regular idiom in
worktree-related code; for instance, it is employed by
get_linked_worktree(), as well.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
---

Notes:
    This is a followup to 5f4ee57ad9 (worktree: avoid dead-code in
    conditional, 2020-06-24) which dropped dead code from the manual
    normalization done by get_main_worktree() but which did not
    eliminate the special cases.
    
    It's also a direct response to Junio's observation[1] that it would
    be better if we didn't have to handle these special cases in the
    first place.
    
    [1]: https://lore.kernel.org/git/xmqqbll8569x.fsf@gitster.c.googlers.com/

 worktree.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/worktree.c b/worktree.c
index 355824bf87..62217b4a6b 100644
--- a/worktree.c
+++ b/worktree.c
@@ -49,10 +49,8 @@ static struct worktree *get_main_worktree(void)
 	struct worktree *worktree = NULL;
 	struct strbuf worktree_path = STRBUF_INIT;
 
-	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
-	if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git */
-	    !strbuf_strip_suffix(&worktree_path, "/.git")) /* in worktree */
-		strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */
+	strbuf_add_real_path(&worktree_path, get_git_common_dir());
+	strbuf_strip_suffix(&worktree_path, "/.git");
 
 	worktree = xcalloc(1, sizeof(*worktree));
 	worktree->path = strbuf_detach(&worktree_path, NULL);
-- 
2.28.0.203.gce1f2e0ef1