Selections spans should not split surrogate pair.

When committing a span after a revert, the offset logic was such that it
split a surrogate unicode pair used to express an emoji.
Checking the last character of the span lets us avoid this problem.

Fix for bug 19255233.

Change-Id: I07d18d9002b5075f7925319dd05962011656c311

1 files changed, 36 insertions, 0 deletions

diff --git a/tests/src/com/android/inputmethod/latin/common/UnicodeSurrogateTests.java b/tests/src/com/android/inputmethod/latin/common/UnicodeSurrogateTests.java
new file mode 100644
index 000000000..59bb08292
--- /dev/null
+++ b/tests/src/com/android/inputmethod/latin/common/UnicodeSurrogateTests.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+package com.android.inputmethod.latin.common;
+
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+@SmallTest
+public class UnicodeSurrogateTests extends AndroidTestCase {
+
+    public void testIsLowSurrogate() {
+        assertFalse(UnicodeSurrogate.isLowSurrogate('\uD7FF'));
+        assertTrue(UnicodeSurrogate.isLowSurrogate('\uD83D'));
+        assertFalse(UnicodeSurrogate.isLowSurrogate('\uDC00'));
+    }
+
+    public void testIsHighSurrogate() {
+        assertFalse(UnicodeSurrogate.isHighSurrogate('\uDBFF'));
+        assertTrue(UnicodeSurrogate.isHighSurrogate('\uDE25'));
+        assertFalse(UnicodeSurrogate.isHighSurrogate('\uE000'));
+    }
+}