refs: move ref name helpers around

strbuf_branchname(), strbuf_check_{branch,tag}_ref() are helper
functions to deal with branch and tag names, and the fact that they
happen to use strbuf to hold the name of a branch or a tag is not
essential.  These functions fit better in the refs API than strbuf
API, the latter of which is about string manipulations.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/refs.c b/refs.c
index 5f729ed412..59a9223d4c 100644
--- a/refs.c
+++ b/refs.c
@@ -697,6 +697,53 @@ static char *substitute_branch_name(struct repository *r,
 	return NULL;
 }
 
+void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
+{
+	int len = strlen(name);
+	struct interpret_branch_name_options options = {
+		.allowed = allowed
+	};
+	int used = repo_interpret_branch_name(the_repository, name, len, sb,
+					      &options);
+
+	if (used < 0)
+		used = 0;
+	strbuf_add(sb, name + used, len - used);
+}
+
+int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
+{
+	if (startup_info->have_repository)
+		strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
+	else
+		strbuf_addstr(sb, name);
+
+	/*
+	 * This splice must be done even if we end up rejecting the
+	 * name; builtin/branch.c::copy_or_rename_branch() still wants
+	 * to see what the name expanded to so that "branch -m" can be
+	 * used as a tool to correct earlier mistakes.
+	 */
+	strbuf_splice(sb, 0, 0, "refs/heads/", 11);
+
+	if (*name == '-' ||
+	    !strcmp(sb->buf, "refs/heads/HEAD"))
+		return -1;
+
+	return check_refname_format(sb->buf, 0);
+}
+
+int strbuf_check_tag_ref(struct strbuf *sb, const char *name)
+{
+	if (name[0] == '-')
+		return -1;
+
+	strbuf_reset(sb);
+	strbuf_addf(sb, "refs/tags/%s", name);
+
+	return check_refname_format(sb->buf, 0);
+}
+
 int repo_dwim_ref(struct repository *r, const char *str, int len,
 		  struct object_id *oid, char **ref, int nonfatal_dangling_mark)
 {