Merge branch 'jc/branch-name-sanity'

"git branch" and "git checkout -b" are now forbidden from creating
a branch whose name is "HEAD".

* jc/branch-name-sanity:
  builtin/branch: remove redundant check for HEAD
  branch: correctly reject refs/heads/{-dash,HEAD}
  branch: split validate_new_branchname() into two
  branch: streamline "attr_only" handling in validate_new_branchname()

2 files changed, 9 insertions, 12 deletions

diff --git a/builtin/branch.c b/builtin/branch.c
index 33fd5fc..5fc57cd 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -463,7 +463,6 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 	struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
 	struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
 	int recovery = 0;
-	int clobber_head_ok;
 
 	if (!oldname) {
 		if (copy)
@@ -487,9 +486,10 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 	 * A command like "git branch -M currentbranch currentbranch" cannot
 	 * cause the worktree to become inconsistent with HEAD, so allow it.
 	 */
-	clobber_head_ok = !strcmp(oldname, newname);
-
-	validate_new_branchname(newname, &newref, force, clobber_head_ok);
+	if (!strcmp(oldname, newname))
+		validate_branchname(newname, &newref);
+	else
+		validate_new_branchname(newname, &newref, force);
 
 	reject_rebase_or_bisect_branch(oldref.buf);
 
@@ -793,9 +793,6 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 	} else if (argc > 0 && argc <= 2) {
 		struct branch *branch = branch_get(argv[0]);
 
-		if (!strcmp(argv[0], "HEAD"))
-			die(_("it does not make sense to create 'HEAD' manually"));
-
 		if (!branch)
 			die(_("no such branch '%s'"), argv[0]);
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 7d8bcc3..3faae382 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1287,11 +1287,11 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	if (opts.new_branch) {
 		struct strbuf buf = STRBUF_INIT;
 
-		opts.branch_exists =
-			validate_new_branchname(opts.new_branch, &buf,
-						!!opts.new_branch_force,
-						!!opts.new_branch_force);
-
+		if (opts.new_branch_force)
+			opts.branch_exists = validate_branchname(opts.new_branch, &buf);
+		else
+			opts.branch_exists =
+				validate_new_branchname(opts.new_branch, &buf, 0);
 		strbuf_release(&buf);
 	}