sequencer: tighten label lookups

The `label` command creates a ref refs/rewritten/<label> that the
`reset` and `merge` commands resolve by calling lookup_label(). That
uses lookup_commit_reference_by_name() to look up the label ref. As
lookup_commit_reference_by_name() uses the dwim rules when looking up
the label it will look for a branch named
refs/heads/refs/rewritten/<label> and return that instead of an error if
the branch exists and the label does not. Fix this by using read_ref()
followed by lookup_commit_object() when looking up labels.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
This commit is contained in:
Phillip Wood 2022-11-10 16:43:41 +00:00 committed by Taylor Blau
parent 82766b2961
commit 688d82f254
2 changed files with 17 additions and 6 deletions

View File

@ -3694,15 +3694,17 @@ static const char *reflog_message(struct replay_opts *opts,
return buf.buf;
}
static struct commit *lookup_label(const char *label, int len,
struct strbuf *buf)
static struct commit *lookup_label(struct repository *r, const char *label,
int len, struct strbuf *buf)
{
struct commit *commit;
struct object_id oid;
strbuf_reset(buf);
strbuf_addf(buf, "refs/rewritten/%.*s", len, label);
commit = lookup_commit_reference_by_name(buf->buf);
if (!commit) {
if (!read_ref(buf->buf, &oid)) {
commit = lookup_commit_object(r, &oid);
} else {
/* fall back to non-rewritten ref or commit */
strbuf_splice(buf, 0, strlen("refs/rewritten/"), "", 0);
commit = lookup_commit_reference_by_name(buf->buf);
@ -3753,7 +3755,7 @@ static int do_reset(struct repository *r,
break;
len = i;
commit = lookup_label(name, len, &ref_name);
commit = lookup_label(r, name, len, &ref_name);
if (!commit) {
ret = -1;
goto cleanup;
@ -3852,7 +3854,7 @@ static int do_merge(struct repository *r,
k = strcspn(p, " \t\n");
if (!k)
continue;
merge_commit = lookup_label(p, k, &ref_name);
merge_commit = lookup_label(r, p, k, &ref_name);
if (!merge_commit) {
ret = error(_("unable to parse '%.*s'"), k, p);
goto leave_merge;

View File

@ -146,6 +146,15 @@ test_expect_success '`reset` rejects trees' '
test_must_be_empty out
'
test_expect_success '`reset` only looks for labels under refs/rewritten/' '
test_when_finished "test_might_fail git rebase --abort" &&
git branch refs/rewritten/my-label A &&
test_must_fail env GIT_SEQUENCE_EDITOR="echo reset my-label >" \
git rebase -i B C >out 2>err &&
grep "could not resolve ${SQ}my-label${SQ}" err &&
test_must_be_empty out
'
test_expect_success 'failed `merge -C` writes patch (may be rescheduled, too)' '
test_when_finished "test_might_fail git rebase --abort" &&
git checkout -b conflicting-merge A &&