Fix git branch -m for symrefs.

This had two problems with symrefs. First, it copied the actual sha1
instead of the "pointer", second it failed to remove the old ref after a
successful rename.

Given that till now delete_ref() always dereferenced symrefs, a new
parameters has been introduced to delete_ref() to allow deleting refs
without a dereference.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 37 insertions, 22 deletions

diff --git a/refs.c b/refs.c
index 39a3b2380..b92930175 100644
--- a/refs.c
+++ b/refs.c
@@ -912,25 +912,33 @@ static int repack_without_ref(const char *refname)
 	return commit_lock_file(&packlock);
 }
 
-int delete_ref(const char *refname, const unsigned char *sha1)
+int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 {
 	struct ref_lock *lock;
-	int err, i, ret = 0, flag = 0;
+	int err, i = 0, ret = 0, flag = 0;
 
 	lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 	if (!lock)
 		return 1;
 	if (!(flag & REF_ISPACKED)) {
 		/* loose */
-		i = strlen(lock->lk->filename) - 5; /* .lock */
-		lock->lk->filename[i] = 0;
-		err = unlink(lock->lk->filename);
+		const char *path;
+
+		if (!(delopt & REF_NODEREF)) {
+			i = strlen(lock->lk->filename) - 5; /* .lock */
+			lock->lk->filename[i] = 0;
+			path = lock->lk->filename;
+		} else {
+			path = git_path(refname);
+		}
+		err = unlink(path);
 		if (err && errno != ENOENT) {
 			ret = 1;
 			error("unlink(%s) failed: %s",
-			      lock->lk->filename, strerror(errno));
+			      path, strerror(errno));
 		}
-		lock->lk->filename[i] = '.';
+		if (!(delopt & REF_NODEREF))
+			lock->lk->filename[i] = '.';
 	}
 	/* removing the loose one could have resurrected an earlier
 	 * packed one.  Also, if it was not loose we need to repack
@@ -955,11 +963,16 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 	struct ref_lock *lock;
 	struct stat loginfo;
 	int log = !lstat(git_path("logs/%s", oldref), &loginfo);
+	const char *symref = NULL;
+	int is_symref = 0;
 
 	if (S_ISLNK(loginfo.st_mode))
 		return error("reflog for %s is a symlink", oldref);
 
-	if (!resolve_ref(oldref, orig_sha1, 1, &flag))
+	symref = resolve_ref(oldref, orig_sha1, 1, &flag);
+	if (flag & REF_ISSYMREF)
+		is_symref = 1;
+	if (!symref)
 		return error("refname %s not found", oldref);
 
 	if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
@@ -979,12 +992,12 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 		return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
 			oldref, strerror(errno));
 
-	if (delete_ref(oldref, orig_sha1)) {
+	if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
 		error("unable to delete old %s", oldref);
 		goto rollback;
 	}
 
-	if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
+	if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
 		if (errno==EISDIR) {
 			if (remove_empty_directories(git_path("%s", newref))) {
 				error("Directory not empty: %s", newref);
@@ -1022,18 +1035,20 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 	}
 	logmoved = log;
 
-	lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
-	if (!lock) {
-		error("unable to lock %s for update", newref);
-		goto rollback;
-	}
-
-	lock->force_write = 1;
-	hashcpy(lock->old_sha1, orig_sha1);
-	if (write_ref_sha1(lock, orig_sha1, logmsg)) {
-		error("unable to write current sha1 into %s", newref);
-		goto rollback;
-	}
+	if (!is_symref) {
+		lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
+		if (!lock) {
+			error("unable to lock %s for update", newref);
+			goto rollback;
+		}
+		lock->force_write = 1;
+		hashcpy(lock->old_sha1, orig_sha1);
+		if (write_ref_sha1(lock, orig_sha1, logmsg)) {
+			error("unable to write current sha1 into %s", newref);
+			goto rollback;
+		}
+	} else
+		create_symref(newref, symref, logmsg);
 
 	return 0;