Adjust common prefix/suffix correctly for InsertIncrementalTextCommand

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/editing/InputMethodController.h"
 
 #include <memory>
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Range.h"
@@ skipping 194 matching lines @@
                    .end()
                    .computeOffsetInContainerNode());
 
   controller().setComposition(String("a"), underlines, 1, 1);
   EXPECT_STREQ("\xF0\x9F\x8F\x86\x61", div->innerText().utf8().data());
 
   controller().setComposition(String("ab"), underlines, 2, 2);
   EXPECT_STREQ("\xF0\x9F\x8F\x86\x61\x62", div->innerText().utf8().data());
 }
 
+TEST_F(InputMethodControllerTest, SetCompositionWithGraphemeCluster) {
+  insertHTMLElement("<div id='sample' contenteditable></div>", "sample");
+
+  Vector<CompositionUnderline> underlines;
+  underlines.push_back(CompositionUnderline(6, 6, Color(255, 0, 0), false, 0));
+  document().updateStyleAndLayout();
+
+  // UTF16 = 0x0939 0x0947 0x0932 0x0932. Note that 0x0932 0x0932 is a grapheme
+  // cluster.
+  controller().setComposition(
+      String::fromUTF8("\xE0\xA4\xB9\xE0\xA5\x87\xE0\xA4\xB2\xE0\xA4\xB2"),
+      underlines, 4, 4);
+  EXPECT_EQ(4u, controller().getSelectionOffsets().start());
+  EXPECT_EQ(4u, controller().getSelectionOffsets().end());
+
+  // UTF16 = 0x0939 0x0947 0x0932 0x094D 0x0932 0x094B.
+  controller().setComposition(
+      String::fromUTF8("\xE0\xA4\xB9\xE0\xA5\x87\xE0\xA4\xB2\xE0\xA5\x8D\xE0"
+                       "\xA4\xB2\xE0\xA5\x8B"),
+      underlines, 6, 6);
+  EXPECT_EQ(6u, controller().getSelectionOffsets().start());
+  EXPECT_EQ(6u, controller().getSelectionOffsets().end());
+}
+
+TEST_F(InputMethodControllerTest,
+       SetCompositionWithGraphemeClusterAndMultipleNodes) {
+  Element* div =
+      insertHTMLElement("<div id='sample' contenteditable></div>", "sample");
+
+  Vector<CompositionUnderline> underlines;
+  underlines.push_back(
+      CompositionUnderline(12, 12, Color(255, 0, 0), false, 0));
+  document().updateStyleAndLayout();
+
+  // UTF16 = 0x0939 0x0947 0x0932 0x094D 0x0932 0x094B. 0x0939 0x0947 0x0932 is
+  // a grapheme cluster, so is the remainding 0x0932 0x094B.
+  controller().commitText(
+      String::fromUTF8("\xE0\xA4\xB9\xE0\xA5\x87\xE0\xA4\xB2\xE0\xA5\x8D\xE0"
+                       "\xA4\xB2\xE0\xA5\x8B"),
+      underlines, 1);
+  controller().commitText("\nab ", underlines, 1);
+  controller().setComposition(String("c"), underlines, 1, 1);
+  EXPECT_STREQ(
+      "\xE0\xA4\xB9\xE0\xA5\x87\xE0\xA4\xB2\xE0\xA5\x8D\xE0\xA4\xB2\xE0\xA5"
+      "\x8B\nab c",
+      div->innerText().utf8().data());
+  EXPECT_EQ(11u, controller().getSelectionOffsets().start());
+  EXPECT_EQ(11u, controller().getSelectionOffsets().end());
+
+  controller().setComposition(String("cd"), underlines, 2, 2);
+  EXPECT_STREQ(
+      "\xE0\xA4\xB9\xE0\xA5\x87\xE0\xA4\xB2\xE0\xA5\x8D\xE0\xA4\xB2\xE0\xA5"
+      "\x8B\nab cd",
+      div->innerText().utf8().data());
+  EXPECT_EQ(12u, controller().getSelectionOffsets().start());
+  EXPECT_EQ(12u, controller().getSelectionOffsets().end());
+}
+
 TEST_F(InputMethodControllerTest, SetCompositionKeepingStyle) {
   Element* div = insertHTMLElement(
       "<div id='sample' "
       "contenteditable>abc1<b>2</b>34567<b>8</b>9d<b>e</b>f</div>",
       "sample");
 
   Vector<CompositionUnderline> underlines;
   underlines.push_back(CompositionUnderline(3, 12, Color(255, 0, 0), false, 0));
   controller().setCompositionFromExistingText(underlines, 3, 12);
 
@@ skipping 1196 matching lines @@
   Vector<CompositionUnderline> underlines;
   underlines.push_back(CompositionUnderline(0, 3, Color(255, 0, 0), false, 0));
   controller().setComposition(String("def"), underlines, 0, 3);
   controller().setComposition(String(""), underlines, 0, 3);
   controller().commitText(String("def"), underlines, 0);
 
   EXPECT_STREQ("abc\ndef", textarea->value().utf8().data());
 }
 
 }  // namespace blink