Fix matches_locale function

matches_locale was expecting input locale string to have at most one
underscore; as a result "zh_CN_#Hans" ignores "zh_CN" and matches into
"zh". Fix the match function and add unit tests.

Bug: 27837319
Change-Id: I4e8a66f91cae6ac2a46b6bf21f670d5ea564c7c8
diff --git a/tests/unit/locale_test.cpp b/tests/unit/locale_test.cpp
new file mode 100644
index 0000000..0e515f8
--- /dev/null
+++ b/tests/unit/locale_test.cpp
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include "minui/minui.h"
+
+TEST(LocaleTest, Misc) {
+    EXPECT_TRUE(matches_locale("zh_CN", "zh_CN_#Hans"));
+    EXPECT_TRUE(matches_locale("zh", "zh_CN_#Hans"));
+    EXPECT_FALSE(matches_locale("zh_HK", "zh_CN_#Hans"));
+    EXPECT_TRUE(matches_locale("en_GB", "en_GB"));
+    EXPECT_TRUE(matches_locale("en", "en_GB"));
+    EXPECT_FALSE(matches_locale("en_GB", "en"));
+    EXPECT_FALSE(matches_locale("en_GB", "en_US"));
+}