3 files changed, 35 insertions, 16 deletions

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 63e55e6773..561c33ac8a 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -465,8 +465,7 @@ stat_ref:
 	close(fd);
 	strbuf_rtrim(&sb_contents);
 	buf = sb_contents.buf;
-	if (starts_with(buf, "ref:")) {
-		buf += 4;
+	if (skip_prefix(buf, "ref:", &buf)) {
 		while (isspace(*buf))
 			buf++;
 
@@ -1327,7 +1326,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 {
 	struct files_ref_store *refs =
 		files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
-	struct object_id oid, orig_oid;
+	struct object_id orig_oid;
 	int flag = 0, logmoved = 0;
 	struct ref_lock *lock;
 	struct stat loginfo;
@@ -1395,7 +1394,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 	 */
 	if (!copy && !refs_read_ref_full(&refs->base, newrefname,
 				RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
-				&oid, NULL) &&
+				NULL, NULL) &&
 	    refs_delete_ref(&refs->base, NULL, newrefname,
 			    NULL, REF_NO_DEREF)) {
 		if (errno == EISDIR) {
@@ -2143,13 +2142,24 @@ static struct ref_iterator_vtable files_reflog_iterator_vtable = {
 static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
 						  const char *gitdir)
 {
-	struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
-	struct ref_iterator *ref_iterator = &iter->base;
+	struct dir_iterator *diter;
+	struct files_reflog_iterator *iter;
+	struct ref_iterator *ref_iterator;
 	struct strbuf sb = STRBUF_INIT;
 
-	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
 	strbuf_addf(&sb, "%s/logs", gitdir);
-	iter->dir_iterator = dir_iterator_begin(sb.buf);
+
+	diter = dir_iterator_begin(sb.buf, 0);
+	if (!diter) {
+		strbuf_release(&sb);
+		return empty_ref_iterator_begin();
+	}
+
+	iter = xcalloc(1, sizeof(*iter));
+	ref_iterator = &iter->base;
+
+	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
+	iter->dir_iterator = diter;
 	iter->ref_store = ref_store;
 	strbuf_release(&sb);
 
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index c01c7f5901..4458a0f69c 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1012,14 +1012,23 @@ int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err)
 	}
 
 	/*
-	 * Now that we hold the `packed-refs` lock, make sure that our
-	 * snapshot matches the current version of the file. Normally
-	 * `get_snapshot()` does that for us, but that function
-	 * assumes that when the file is locked, any existing snapshot
-	 * is still valid. We've just locked the file, but it might
-	 * have changed the moment *before* we locked it.
+	 * There is a stat-validity problem might cause `update-ref -d`
+	 * lost the newly commit of a ref, because a new `packed-refs`
+	 * file might has the same on-disk file attributes such as
+	 * timestamp, file size and inode value, but has a changed
+	 * ref value.
+	 *
+	 * This could happen with a very small chance when
+	 * `update-ref -d` is called and at the same time another
+	 * `pack-refs --all` process is running.
+	 *
+	 * Now that we hold the `packed-refs` lock, it is important
+	 * to make sure we could read the latest version of
+	 * `packed-refs` file no matter we have just mmap it or not.
+	 * So what need to do is clear the snapshot if we hold it
+	 * already.
 	 */
-	validate_snapshot(refs);
+	clear_snapshot(refs);
 
 	/*
 	 * Now make sure that the packed-refs file as it exists in the
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index f2d8c0123a..ff2436c0fb 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -262,7 +262,7 @@ int refs_rename_ref_available(struct ref_store *refs,
  * after calling ref_iterator_advance() again or calling
  * ref_iterator_abort(), you must make a copy. When the iteration has
  * been exhausted, ref_iterator_advance() releases any resources
- * assocated with the iteration, frees the ref_iterator object, and
+ * associated with the iteration, frees the ref_iterator object, and
  * returns ITER_DONE. If you want to abort the iteration early, call
  * ref_iterator_abort(), which also frees the ref_iterator object and
  * any associated resources. If there was an internal error advancing