refs: kill set_worktree_head_symref()

70999e9cec (branch -m: update all per-worktree HEADs - 2016-03-27)
added this function in order to update HEADs of all relevant
worktrees, when a branch is renamed.

It, as a public ref api, kind of breaks abstraction when it uses
internal functions of files backend. With the introduction of
refs_create_symref(), we can move back pretty close to the code before
70999e9cec, where create_symref() was used for updating HEAD.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

branch.c

@@ -353,19 +353,19 @@ int replace_each_worktree_head_symref(const char *oldref, const char *newref,
 	int i;
 
 	for (i = 0; worktrees[i]; i++) {
+		struct ref_store *refs;
+
 		if (worktrees[i]->is_detached)
 			continue;
 		if (worktrees[i]->head_ref &&
 		    strcmp(oldref, worktrees[i]->head_ref))
 			continue;
 
-		if (set_worktree_head_symref(get_worktree_git_dir(worktrees[i]),
+		refs = get_worktree_ref_store(worktrees[i]);
-					     newref, logmsg)) {
+		if (refs_create_symref(refs, "HEAD", newref, logmsg))
-			ret = -1;
+			ret = error(_("HEAD of working tree %s is not updated"),
-			error(_("HEAD of working tree %s is not updated"),
 				    worktrees[i]->path);
 	}
-	}
 
 	free_worktrees(worktrees);
 	return ret;

refs.h

@@ -402,16 +402,6 @@ int refs_create_symref(struct ref_store *refs, const char *refname,
 		       const char *target, const char *logmsg);
 int create_symref(const char *refname, const char *target, const char *logmsg);
 
-/*
- * Update HEAD of the specified gitdir.
- * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but
- * this can update the main working tree's HEAD regardless of where
- * $GIT_DIR points to.
- * Return 0 if successful, non-zero otherwise.
- * */
-int set_worktree_head_symref(const char *gitdir, const char *target,
-			     const char *logmsg);
-
 enum action_on_err {
 	UPDATE_REFS_MSG_ON_ERR,
 	UPDATE_REFS_DIE_ON_ERR,

refs/files-backend.c

@@ -3160,50 +3160,6 @@ static int files_create_symref(struct ref_store *ref_store,
 	return ret;
 }
 
-int set_worktree_head_symref(const char *gitdir, const char *target, const char *logmsg)
-{
-	/*
-	 * FIXME: this obviously will not work well for future refs
-	 * backends. This function needs to die.
-	 */
-	struct files_ref_store *refs =
-		files_downcast(get_main_ref_store(),
-			       REF_STORE_WRITE,
-			       "set_head_symref");
-
-	static struct lock_file head_lock;
-	struct ref_lock *lock;
-	struct strbuf head_path = STRBUF_INIT;
-	const char *head_rel;
-	int ret;
-
-	strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));
-	if (hold_lock_file_for_update(&head_lock, head_path.buf,
-				      LOCK_NO_DEREF) < 0) {
-		struct strbuf err = STRBUF_INIT;
-		unable_to_lock_message(head_path.buf, errno, &err);
-		error("%s", err.buf);
-		strbuf_release(&err);
-		strbuf_release(&head_path);
-		return -1;
-	}
-
-	/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for
-	   linked trees */
-	head_rel = remove_leading_path(head_path.buf,
-				       absolute_path(get_git_common_dir()));
-	/* to make use of create_symref_locked(), initialize ref_lock */
-	lock = xcalloc(1, sizeof(struct ref_lock));
-	lock->lk = &head_lock;
-	lock->ref_name = xstrdup(head_rel);
-
-	ret = create_symref_locked(refs, lock, head_rel, target, logmsg);
-
-	unlock_ref(lock); /* will free lock */
-	strbuf_release(&head_path);
-	return ret;
-}
-
 static int files_reflog_exists(struct ref_store *ref_store,
 			       const char *refname)
 {

t/t1407-worktree-ref-store.sh

@@ -37,4 +37,16 @@ test_expect_success 'resolve_ref(<per-worktree-ref>)' '
 	test_cmp expected actual
 '
 
+test_expect_success 'create_symref(FOO, refs/heads/master)' '
+	$RWT create-symref FOO refs/heads/master nothing &&
+	echo refs/heads/master >expected &&
+	git -C wt symbolic-ref FOO >actual &&
+	test_cmp expected actual &&
+
+	$RMAIN create-symref FOO refs/heads/wt-master nothing &&
+	echo refs/heads/wt-master >expected &&
+	git symbolic-ref FOO >actual &&
+	test_cmp expected actual
+'
+
 test_done