1 files changed, 39 insertions, 1 deletions

diff --git a/builtin-check-ref-format.c b/builtin-check-ref-format.c
index f9381e0..b106c65 100644
--- a/builtin-check-ref-format.c
+++ b/builtin-check-ref-format.c
@@ -7,8 +7,37 @@
 #include "builtin.h"
 #include "strbuf.h"
 
+static const char builtin_check_ref_format_usage[] =
+"git check-ref-format [--print] <refname>\n"
+"   or: git check-ref-format --branch <branchname-shorthand>";
+
+/*
+ * Replace each run of adjacent slashes in src with a single slash,
+ * and write the result to dst.
+ *
+ * This function is similar to normalize_path_copy(), but stripped down
+ * to meet check_ref_format's simpler needs.
+ */
+static void collapse_slashes(char *dst, const char *src)
+{
+	char ch;
+	char prev = '\0';
+
+	while ((ch = *src++) != '\0') {
+		if (prev == '/' && ch == prev)
+			continue;
+
+		*dst++ = ch;
+		prev = ch;
+	}
+	*dst = '\0';
+}
+
 int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
 {
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(builtin_check_ref_format_usage);
+
 	if (argc == 3 && !strcmp(argv[1], "--branch")) {
 		struct strbuf sb = STRBUF_INIT;
 
@@ -17,7 +46,16 @@ int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
 		printf("%s\n", sb.buf + 11);
 		exit(0);
 	}
+	if (argc == 3 && !strcmp(argv[1], "--print")) {
+		char *refname = xmalloc(strlen(argv[2]) + 1);
+
+		if (check_ref_format(argv[2]))
+			exit(1);
+		collapse_slashes(refname, argv[2]);
+		printf("%s\n", refname);
+		exit(0);
+	}
 	if (argc != 2)
-		usage("git check-ref-format refname");
+		usage(builtin_check_ref_format_usage);
 	return !!check_ref_format(argv[1]);
 }