git_snpath(path, sizeof(path), "%s", refname);
+ /*
+ * We might have to loop back here to avoid a race
+ * condition: first we lstat() the file, then we try
+ * to read it as a link or as a file. But if somebody
+ * changes the type of the file (file <-> directory
+ * <-> symlink) between the lstat() and reading, then
+ * we don't want to report that as an error but rather
+ * try again starting with the lstat().
+ */
+ stat_ref:
if (lstat(path, &st) < 0) {
if (errno == ENOENT)
return handle_missing_loose_ref(refname, sha1,
/* Follow "normalized" - ie "refs/.." symlinks by hand */
if (S_ISLNK(st.st_mode)) {
len = readlink(path, buffer, sizeof(buffer)-1);
- if (len < 0)
- return NULL;
+ if (len < 0) {
+ if (errno == ENOENT || errno == EINVAL)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return NULL;
+ }
buffer[len] = 0;
if (!prefixcmp(buffer, "refs/") &&
!check_refname_format(buffer, 0)) {
* a ref
*/
fd = open(path, O_RDONLY);
- if (fd < 0)
- return NULL;
+ if (fd < 0) {
+ if (errno == ENOENT)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return NULL;
+ }
len = read_in_full(fd, buffer, sizeof(buffer)-1);
close(fd);
if (len < 0)