check-ref-format: handle subcommands in separate functions

The code for each subcommand should be easier to read and manipulate
this way.

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

builtin/check-ref-format.c

@@ -33,28 +33,36 @@ static void collapse_slashes(char *dst, const char *src)
 	*dst = '\0';
 }
 
-int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
+static int check_ref_format_branch(const char *arg)
 {
-	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;
 
-		if (strbuf_check_branch_ref(&sb, argv[2]))
-			die("'%s' is not a valid branch name", argv[2]);
+	if (strbuf_check_branch_ref(&sb, arg))
+		die("'%s' is not a valid branch name", arg);
 	printf("%s\n", sb.buf + 11);
-		exit(0);
-	}
-	if (argc == 3 && !strcmp(argv[1], "--print")) {
-		char *refname = xmalloc(strlen(argv[2]) + 1);
+	return 0;
+}
+
+static int check_ref_format_print(const char *arg)
+{
+	char *refname = xmalloc(strlen(arg) + 1);
 
-		if (check_ref_format(argv[2]))
-			exit(1);
-		collapse_slashes(refname, argv[2]);
+	if (check_ref_format(arg))
+		return 1;
+	collapse_slashes(refname, arg);
 	printf("%s\n", refname);
-		exit(0);
-	}
+	return 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"))
+		return check_ref_format_branch(argv[2]);
+	if (argc == 3 && !strcmp(argv[1], "--print"))
+		return check_ref_format_print(argv[2]);
 	if (argc != 2)
 		usage(builtin_check_ref_format_usage);
 	return !!check_ref_format(argv[1]);