Workaround for setComposition styling clobber

third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp b/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
index cfce7ed4321ce2a651f7a175a04aecf55e470121..e9041ed208867ad4fdec8a1aad9cacac15144aaf 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
@@ -115,6 +115,58 @@ TEST_F(InputMethodControllerTest, SetCompositionFromExistingText)
     PlainTextRange plainTextRange(PlainTextRange::create(*div, *range));
     EXPECT_EQ(0u, plainTextRange.start());
     EXPECT_EQ(5u, plainTextRange.end());
+
+    controller().setComposition(String("hellobar"), underlines, 8, 8);
+    range = controller().compositionRange();
+    EXPECT_EQ(0, range->startOffset());
+    EXPECT_EQ(8, range->endOffset());
+}
+
+TEST_F(InputMethodControllerTest, SetCompositionKeepingStyle)
+{
+    Element* div = insertHTMLElement(
+        "<div id='sample' contenteditable='true'><b>he</b>llo</div>", "sample");
+
+    Vector<CompositionUnderline> underlines;
+    underlines.append(CompositionUnderline(0, 5, Color(255, 0, 0), false, 0));
+    controller().setCompositionFromExistingText(underlines, 0, 5);
+
+    controller().setComposition(String("hell"), underlines, 4, 4);
+    EXPECT_STREQ("<b>he</b>ll", div->innerHTML().utf8().data());
+
+    controller().setComposition(String("hello"), underlines, 5, 5);
+    EXPECT_STREQ("<b>he</b>llo", div->innerHTML().utf8().data());

[aelias_OOO_until_Jul13, 2016/09/28 23:58:29]

Please add another test case for backspace.

[yabinh, 2016/10/11 01:42:23]

Line#134 is for backspace(from "hello" to "hell").

+}
+
+TEST_F(InputMethodControllerTest, SetCompositionWithMultiCodeTextKeepingStyle)
+{
+    // U+1F3E0 = 0xF0 0x9F 0x8F 0xA0 (UTF8). It's an emoji character with
+    // surrogate pairs.
+    Element* div = insertHTMLElement(
+        "<div id='sample' contenteditable='true'><b>&#x1f3e0</b></div>", "sample");
+    Vector<CompositionUnderline> underlines;
+    underlines.append(CompositionUnderline(0, 2, Color(255, 0, 0), false, 0));
+    controller().setCompositionFromExistingText(underlines, 0, 2);
+
+    // 0xF0 0x9F 0x8F 0xAB is also an emoji character with surrogate pairs.
+    controller().setComposition(String::fromUTF8("\xF0\x9F\x8F\xAB"), underlines, 2, 2);
+    EXPECT_STREQ("<b>\xF0\x9F\x8F\xAB</b>", div->innerHTML().utf8().data());
+
+    controller().setComposition(String::fromUTF8("\xF0\x9F\x8F\xA0"), underlines, 2, 2);
+    EXPECT_STREQ("<b>\xF0\x9F\x8F\xA0</b>", div->innerHTML().utf8().data());
+
+    // U+0C03 = 0xE0 0xB0 0x83 (UTF8), a telugu character with 1 code point.
+    div = insertHTMLElement(
+        "<div id='sample' contenteditable='true'><b>&#xc03</b></div>", "sample");
+    controller().setCompositionFromExistingText(underlines, 0, 1);
+
+    // 0xE0 0xB0 0x83 0xE0 0xB0 0x83, a telugu character with 2 code points in
+    // 1 grapheme cluster.
+    controller().setComposition(String::fromUTF8("\xE0\xB0\x83\xE0\xB0\x83"), underlines, 2, 2);
+    EXPECT_STREQ("<b>\xE0\xB0\x83\xE0\xB0\x83</b>", div->innerHTML().utf8().data());
+
+    controller().setComposition(String::fromUTF8("\xE0\xB0\x83"), underlines, 1, 1);

[yabinh, 2016/09/27 12:46:47]

Note that if we use code point to decide the common prefix length, this test
will not pass. The reason is that, for now, we can only select (and delete) by
grapheme cluster. we are not able to delete the second "\xE0\xB0\x83".

+    EXPECT_STREQ("<b>\xE0\xB0\x83</b>", div->innerHTML().utf8().data());
 }
 
 TEST_F(InputMethodControllerTest, SelectionOnConfirmExistingText)
@@ -485,7 +537,7 @@ TEST_F(InputMethodControllerTest, CompositionInputEventData)
 
     document().setTitle(emptyString());
     controller().setComposition("ni", underlines, 0, 1);
-    EXPECT_STREQ("beforeinput.data:ni;input.data:ni;", document().title().utf8().data());
+    EXPECT_STREQ("beforeinput.data:i;input.data:i;", document().title().utf8().data());
 
     document().setTitle(emptyString());
     controller().finishComposingText(InputMethodController::KeepSelection);