worktree: prune linked worktree referencing main worktree path

"git worktree prune" detects when multiple entries are associated with
the same path and prunes the duplicates, however, it does not detect
when a linked worktree points at the path of the main worktree.
Although "git worktree add" disallows creating a new worktree with the
same path as the main worktree, such a case can arise outside the
control of Git even without the user mucking with .git/worktree/<id>/
administrative files. For instance:

    $ git clone foo.git
    $ git -C foo worktree add ../bar
    $ rm -rf bar
    $ mv foo bar
    $ git -C bar worktree list
    .../bar deadfeeb [master]
    .../bar deadfeeb [bar]

Help the user recover from such corruption by extending "git worktree
prune" to also detect when a linked worktree is associated with the path
of the main worktree.

Reported-by: Jonathan Müller <jonathanmueller.dev@gmail.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 02a5844705829fe30c626190772b4faa6d9399d2..9fe9e442c7a085169acf7dd49fe87ebc2ccdcb38 100644 (file)
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -156,6 +156,16 @@ static int prune_cmp(const void *a, const void *b)
 
        if ((c = fspathcmp(x->string, y->string)))
            return c;
+       /*
+        * paths same; prune_dupes() removes all but the first worktree entry
+        * having the same path, so sort main worktree ('util' is NULL) above
+        * linked worktrees ('util' not NULL) since main worktree can't be
+        * removed
+        */
+       if (!x->util)
+               return -1;
+       if (!y->util)
+               return 1;
        /* paths same; sort by .git/worktrees/<id> */
        return strcmp(x->util, y->util);
 }
@@ -174,6 +184,7 @@ static void prune_dups(struct string_list *l)
 static void prune_worktrees(void)
 {
        struct strbuf reason = STRBUF_INIT;
+       struct strbuf main_path = STRBUF_INIT;
        struct string_list kept = STRING_LIST_INIT_NODUP;
        DIR *dir = opendir(git_path("worktrees"));
        struct dirent *d;
@@ -191,6 +202,10 @@ static void prune_worktrees(void)
        }
        closedir(dir);
 
+       strbuf_add_absolute_path(&main_path, get_git_common_dir());
+       /* massage main worktree absolute path to match 'gitdir' content */
+       strbuf_strip_suffix(&main_path, "/.");
+       string_list_append(&kept, strbuf_detach(&main_path, NULL));
        prune_dups(&kept);
        string_list_clear(&kept, 1);
 

diff --git a/t/t2401-worktree-prune.sh b/t/t2401-worktree-prune.sh
index fd3916fee058f8c9f6a11b67e394f693a3386b5b..a6ce7f590b64ffcaaf41a7dc9c0b9de7a6aac46a 100755 (executable)
--- a/t/t2401-worktree-prune.sh
+++ b/t/t2401-worktree-prune.sh
@@ -104,4 +104,16 @@ test_expect_success 'prune duplicate (linked/linked)' '
        ! test -d .git/worktrees/w2
 '
 
+test_expect_success 'prune duplicate (main/linked)' '
+       test_when_finished rm -fr repo wt &&
+       test_create_repo repo &&
+       test_commit -C repo x &&
+       git -C repo worktree add --detach ../wt &&
+       rm -fr wt &&
+       mv repo wt &&
+       git -C wt worktree prune --verbose >actual &&
+       test_i18ngrep "duplicate entry" actual &&
+       ! test -d .git/worktrees/wt
+'
+
 test_done