git check-ref-format: add options --allow-onelevel and --refspec-pattern

Also add tests of the new options.  (Actually, one big reason to add
the new options is to make it easy to test check_ref_format(), though
the options should also be useful to other scripts.)

Interpret the result of check_ref_format() based on which types of
refnames are allowed.  However, because check_ref_format() can only
return a single value, one test case is still broken.  Specifically,
the case "git check-ref-format --onelevel '*'" incorrectly succeeds
because check_ref_format() returns CHECK_REF_FORMAT_ONELEVEL for this
refname even though the refname is also CHECK_REF_FORMAT_WILDCARD.
The type of check that leads to this failure is used elsewhere in
"real" code and could lead to bugs; it will be fixed over the next few
commits.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/check-ref-format.c b/builtin/check-ref-format.c
index 0723cf2..7295954 100644
--- a/builtin/check-ref-format.c
+++ b/builtin/check-ref-format.c
@@ -8,7 +8,7 @@
 #include "strbuf.h"
 
 static const char builtin_check_ref_format_usage[] =
-"git check-ref-format [--print] <refname>\n"
+"git check-ref-format [--print] [options] <refname>\n"
 "   or: git check-ref-format --branch <branchname-shorthand>";
 
 /*
@@ -45,27 +45,65 @@
 	return 0;
 }
 
-static int check_ref_format_print(const char *arg)
+static void refname_format_print(const char *arg)
 {
 	char *refname = xmalloc(strlen(arg) + 1);
 
-	if (check_ref_format(arg))
-		return 1;
 	collapse_slashes(refname, arg);
 	printf("%s\n", refname);
-	return 0;
 }
 
+#define REFNAME_ALLOW_ONELEVEL 1
+#define REFNAME_REFSPEC_PATTERN 2
+
 int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
 {
+	int i;
+	int print = 0;
+	int flags = 0;
+
 	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)
+
+	for (i = 1; i < argc && argv[i][0] == '-'; i++) {
+		if (!strcmp(argv[i], "--print"))
+			print = 1;
+		else if (!strcmp(argv[i], "--allow-onelevel"))
+			flags |= REFNAME_ALLOW_ONELEVEL;
+		else if (!strcmp(argv[i], "--no-allow-onelevel"))
+			flags &= ~REFNAME_ALLOW_ONELEVEL;
+		else if (!strcmp(argv[i], "--refspec-pattern"))
+			flags |= REFNAME_REFSPEC_PATTERN;
+		else
+			usage(builtin_check_ref_format_usage);
+	}
+	if (! (i == argc - 1))
 		usage(builtin_check_ref_format_usage);
-	return !!check_ref_format(argv[1]);
+
+	switch (check_ref_format(argv[i])) {
+	case CHECK_REF_FORMAT_OK:
+		break;
+	case CHECK_REF_FORMAT_ERROR:
+		return 1;
+	case CHECK_REF_FORMAT_ONELEVEL:
+		if (!(flags & REFNAME_ALLOW_ONELEVEL))
+			return 1;
+		else
+			break;
+	case CHECK_REF_FORMAT_WILDCARD:
+		if (!(flags & REFNAME_REFSPEC_PATTERN))
+			return 1;
+		else
+			break;
+	default:
+		die("internal error: unexpected value from check_ref_format()");
+	}
+
+	if (print)
+		refname_format_print(argv[i]);
+
+	return 0;
 }