check-ref-format: simplify --print implementation

normalize_path_copy() is a complicated function, but most of its
functionality will never apply to a ref name that has been checked
with check_ref_format().

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: jrn

builtin-check-ref-format.c

@@ -7,6 +7,28 @@
 #include "builtin.h"
 #include "strbuf.h"
 
+/*
+ * 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 == 3 && !strcmp(argv[1], "--branch")) {
@@ -22,8 +44,7 @@ int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
 
 		if (check_ref_format(argv[2]))
 			exit(1);
-		if (normalize_path_copy(refname, argv[2]))
-			die("Could not normalize ref name '%s'", argv[2]);
+		collapse_slashes(refname, argv[2]);
 		printf("%s\n", refname);
 		exit(0);
 	}