Prevent copyTextTo() from Breaking Code Points

third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp

Index: third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp
diff --git a/third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp b/third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp
index 4a1890b1188d3e753c65b26781d70c271cfee20a..7dc224ac57b6aeac6229f93129714f9311aaf28a 100644
--- a/third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp
+++ b/third_party/WebKit/Source/core/editing/iterators/TextIteratorTest.cpp
@@ -493,4 +493,24 @@ TEST_F(TextIteratorTest, characterAt)
     EXPECT_EQ('o', iter2.characterAt(4)) << message2;
 }
 
+TEST_F(TextIteratorTest, CopyWholeCodePoints)
+{
+    const char* bodyContent = "&#x13000;&#x13001;&#x13002; &#x13140;&#x13141;.";
+    setBodyContent(bodyContent);
+    updateLayoutAndStyleForPainting();
+
+    const UChar expected[] = {0xD80C, 0xDC00, 0xD80C, 0xDC01, 0xD80C, 0xDC02, ' ', 0xD80C, 0xDD40, 0xD80C, 0xDD41, '.'};
+
+    EphemeralRange range(EphemeralRange::rangeOfContents(document()));
+    TextIterator iter(range.startPosition(), range.endPosition());
+    Vector<UChar> buffer;
+    EXPECT_EQ(2, iter.copyTextTo(buffer, 0, 1)) << "Should emit 2 UChars for 'U+13000'.";
+    EXPECT_EQ(4, iter.copyTextTo(buffer, 2, 3)) << "Should emit 4 UChars for 'U+13001U+13002'.";
+    EXPECT_EQ(3, iter.copyTextTo(buffer, 6, 2)) << "Should emit 3 UChars for ' U+13140'.";
+    EXPECT_EQ(2, iter.copyTextTo(buffer, 9, 2)) << "Should emit 2 UChars for 'U+13141'.";
+    EXPECT_EQ(1, iter.copyTextTo(buffer, 11, 1)) << "Should emit 1 UChar for '.'.";
+    for (int i = 0; i < 12; i++)
+        EXPECT_EQ(expected[i], buffer[i]);
+}
+
 } // namespace blink