refs: don't dereference on rename

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 2f98eebe94e1a7ca42b2999eeb3868e2b7096a39..15ba456d68062ed15cb96454008b8c57f1f192e9 100644 (file)
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2333,7 +2333,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
        if (log && S_ISLNK(loginfo.st_mode))
                return error("reflog for %s is a symlink", oldrefname);
 
-       if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, orig_sha1, &flag))
+       if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
+                               orig_sha1, &flag))
                return error("refname %s not found", oldrefname);
 
        if (flag & REF_ISSYMREF)
@@ -2351,8 +2352,16 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
                goto rollback;
        }
 
-       if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
-           delete_ref(newrefname, sha1, REF_NODEREF)) {
+       /*
+        * Since we are doing a shallow lookup, sha1 is not the
+        * correct value to pass to delete_ref as old_sha1. But that
+        * doesn't matter, because an old_sha1 check wouldn't add to
+        * the safety anyway; we want to delete the reference whatever
+        * its current value.
+        */
+       if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
+                          sha1, NULL) &&
+           delete_ref(newrefname, NULL, REF_NODEREF)) {
                if (errno==EISDIR) {
                        struct strbuf path = STRBUF_INIT;
                        int result;
@@ -2376,7 +2385,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 
        logmoved = log;
 
-       lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);
+       lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,
+                                  NULL, &err);
        if (!lock) {
                error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
                strbuf_release(&err);
@@ -2394,7 +2404,8 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
        return 0;
 
  rollback:
-       lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);
+       lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,
+                                  NULL, &err);
        if (!lock) {
                error("unable to lock %s for rollback: %s", oldrefname, err.buf);
                strbuf_release(&err);