summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLibravatar Michael Haggerty <mhagger@alum.mit.edu>2016-04-25 17:38:35 +0200
committerLibravatar Michael Haggerty <mhagger@alum.mit.edu>2016-06-13 11:23:50 +0200
commit8169d0d06ad721aa54d95f044f4b097d79151ea2 (patch)
treecad95d43a435cd31887ebf710e68969aeca234e9
parentrefs: resolve symbolic refs first (diff)
downloadtgif-8169d0d06ad721aa54d95f044f4b097d79151ea2.tar.xz
lock_ref_for_update(): don't re-read non-symbolic references
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 <mhagger@alum.mit.edu>
-rw-r--r--refs/files-backend.c48
1 files changed, 30 insertions, 18 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c
index ffc30fd232..7bc18322aa 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3436,33 +3436,45 @@ 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);
+ 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;
- } 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 (!(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) &&