undef/git-commit-vandalism
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

worktree: prune duplicate entries referencing same worktree path

Browse Source 
A fundamental restriction of linked working trees is that there must
only ever be a single worktree associated with a particular path, thus
"git worktree add" explicitly disallows creation of a new worktree at
the same location as an existing registered worktree. Nevertheless,
users can still "shoot themselves in the foot" by mucking with
administrative files in .git/worktree/<id>/. Worse, "git worktree move"
is careless[1] and allows a worktree to be moved atop a registered but
missing worktree (which can happen, for instance, if the worktree is on
removable media). For instance:

    $ git clone foo.git
    $ cd foo
    $ git worktree add ../bar
    $ git worktree add ../baz
    $ rm -rf ../bar
    $ git worktree move ../baz ../bar
    $ git worktree list
    .../foo beefd00f [master]
    .../bar beefd00f [bar]
    .../bar beefd00f [baz]

Help users recover from this form of corruption by teaching "git
worktree prune" to detect when multiple worktrees are associated with
the same path.

[1]: A subsequent commit will fix "git worktree move" validation to be
     more strict.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Eric Sunshine 2020-06-10 02:30:46 -04:00 committed by Junio C Hamano
parent dd9609a12e
commit 4a3ce479ce
2 changed files with 55 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
builtin/worktree.c
View File

@ -67,7 +67,12 @@ static void delete_worktrees_dir_if_empty(void)
rmdir(git_path("worktrees")); /* ignore failed removal */
}
static int should_prune_worktree(const char *id, struct strbuf *reason)
/*
* Return true if worktree entry should be pruned, along with the reason for
* pruning. Otherwise, return false and the worktree's path, or NULL if it
* cannot be determined. Caller is responsible for freeing returned path.
*/
static int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath)
{
struct stat st;
char *path;
@ -75,6 +80,7 @@ static int should_prune_worktree(const char *id, struct strbuf *reason)
size_t len;
ssize_t read_result;
*wtpath = NULL;
if (!is_directory(git_path("worktrees/%s", id))) {
strbuf_addstr(reason, _("not a valid directory"));
return 1;
@ -120,16 +126,17 @@ static int should_prune_worktree(const char *id, struct strbuf *reason)
}
path[len] = '\0';
if (!file_exists(path)) {
free(path);
if (stat(git_path("worktrees/%s/index", id), &st) ||
st.st_mtime <= expire) {
strbuf_addstr(reason, _("gitdir file points to non-existent location"));
free(path);
return 1;
} else {
*wtpath = path;
return 0;
}
}
free(path);
*wtpath = path;
return 0;
}
@ -141,22 +148,52 @@ static void prune_worktree(const char *id, const char *reason)
delete_git_dir(id);
}
static int prune_cmp(const void *a, const void *b)
{
const struct string_list_item *x = a;
const struct string_list_item *y = b;
int c;
if ((c = fspathcmp(x->string, y->string)))
return c;
/* paths same; sort by .git/worktrees/<id> */
return strcmp(x->util, y->util);
}
static void prune_dups(struct string_list *l)
{
int i;
QSORT(l->items, l->nr, prune_cmp);
for (i = 1; i < l->nr; i++) {
if (!fspathcmp(l->items[i].string, l->items[i - 1].string))
prune_worktree(l->items[i].util, "duplicate entry");
}
}
static void prune_worktrees(void)
{
struct strbuf reason = STRBUF_INIT;
struct string_list kept = STRING_LIST_INIT_NODUP;
DIR *dir = opendir(git_path("worktrees"));
struct dirent *d;
if (!dir)
return;
while ((d = readdir(dir)) != NULL) {
char *path;
if (is_dot_or_dotdot(d->d_name))
continue;
strbuf_reset(&reason);
if (!should_prune_worktree(d->d_name, &reason))
continue;
prune_worktree(d->d_name, reason.buf);
if (should_prune_worktree(d->d_name, &reason, &path))
prune_worktree(d->d_name, reason.buf);
else if (path)
string_list_append(&kept, path)->util = xstrdup(d->d_name);
}
closedir(dir);
prune_dups(&kept);
string_list_clear(&kept, 1);
if (!show_only)
delete_worktrees_dir_if_empty();
strbuf_release(&reason);

12
t/t2401-worktree-prune.sh
View File

@ -92,4 +92,16 @@ test_expect_success 'not prune proper checkouts' '
test -d .git/worktrees/nop
'
test_expect_success 'prune duplicate (linked/linked)' '
test_when_finished rm -fr .git/worktrees w1 w2 &&
git worktree add --detach w1 &&
git worktree add --detach w2 &&
sed "s/w2/w1/" .git/worktrees/w2/gitdir >.git/worktrees/w2/gitdir.new &&
mv .git/worktrees/w2/gitdir.new .git/worktrees/w2/gitdir &&
git worktree prune --verbose >actual &&
test_i18ngrep "duplicate entry" actual &&
test -d .git/worktrees/w1 &&
! test -d .git/worktrees/w2
'
test_done