Before the previous patch, our first read of the reference happened
before the reference was locked, so we couldn't trust its value and had
to read it again. But now that our first read of the reference happens
after acquiring the lock, there is no need to read it a second time. So
move the read_ref_full() call into the (update->type & REF_ISSYMREF)
block.
Signed-off-by: Michael Haggerty <mhag...@alum.mit.edu>
---
refs/files-backend.c | 52 ++++++++++++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 799866f..a9066ba 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3430,33 +3430,45 @@ static int lock_ref_for_update(struct ref_update
*update,
lock = update->lock;
- if (read_ref_full(update->refname,
- mustexist ? RESOLVE_REF_READING : 0,
- lock->old_oid.hash, NULL)) {
- if (update->flags & REF_HAVE_OLD) {
- strbuf_addf(err, "cannot lock ref '%s': can't resolve
old value",
- update->refname);
- return TRANSACTION_GENERIC_ERROR;
- } else {
- hashclr(lock->old_oid.hash);
- }
- }
- if ((update->flags & REF_HAVE_OLD) &&
- hashcmp(lock->old_oid.hash, update->old_sha1)) {
- strbuf_addf(err, "cannot lock ref '%s': is at %s but expected
%s",
- update->refname,
- sha1_to_hex(lock->old_oid.hash),
- sha1_to_hex(update->old_sha1));
- return TRANSACTION_GENERIC_ERROR;
- }
-
if (update->type & REF_ISSYMREF) {
+ if (read_ref_full(update->refname,
+ mustexist ? RESOLVE_REF_READING : 0,
+ lock->old_oid.hash, NULL)) {
+ if (update->flags & REF_HAVE_OLD) {
+ strbuf_addf(err, "cannot lock ref '%s': can't
resolve old value",
+ update->refname);
+ return TRANSACTION_GENERIC_ERROR;
+ } else {
+ hashclr(lock->old_oid.hash);
+ }
+ }
+ if ((update->flags & REF_HAVE_OLD) &&
+ hashcmp(lock->old_oid.hash, update->old_sha1)) {
+ strbuf_addf(err, "cannot lock ref '%s': is at %s but
expected %s",
+ update->refname,
+ sha1_to_hex(lock->old_oid.hash),
+ sha1_to_hex(update->old_sha1));
+ return TRANSACTION_GENERIC_ERROR;
+ }
+
if (!(update->flags & REF_NODEREF)) {
ret = split_symref_update(update, referent.buf,
transaction,
affected_refnames, err);
if (ret)
return ret;
}
+ } else if ((update->flags & REF_HAVE_OLD) &&
+ hashcmp(lock->old_oid.hash, update->old_sha1)) {
+ if (is_null_sha1(update->old_sha1))
+ strbuf_addf(err, "cannot lock ref '%s': reference
already exists",
+ update->refname);
+ else
+ strbuf_addf(err, "cannot lock ref '%s': is at %s but
expected %s",
+ update->refname,
+ sha1_to_hex(lock->old_oid.hash),
+ sha1_to_hex(update->old_sha1));
+
+ return TRANSACTION_GENERIC_ERROR;
}
if ((update->flags & REF_HAVE_NEW) &&
--
2.8.1
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
