[Editing] Let InputMethodController::hasComposition check Range::isConnected().

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 164 matching lines @@
 bool InputMethodController::isAvailable() const {
   return frame().document();
 }
 
 Document& InputMethodController::document() const {
   DCHECK(isAvailable());
   return *frame().document();
 }
 
 bool InputMethodController::hasComposition() const {
-  return m_hasComposition;
+  return m_hasComposition && !m_compositionRange->collapsed() &&
+         m_compositionRange->isConnected();
 }
 
 inline Editor& InputMethodController::editor() const {
   return frame().editor();
 }
 
 void InputMethodController::clear() {
   m_hasComposition = false;
   if (m_compositionRange) {
     m_compositionRange->setStart(&document(), 0);
@@ skipping 111 matching lines @@
                                         int relativeCaretPosition) {
   return textStart + textLength + relativeCaretPosition;
 }
 
 bool InputMethodController::replaceCompositionAndMoveCaret(
     const String& text,
     int relativeCaretPosition) {
   Element* rootEditableElement = frame().selection().rootEditableElement();
   if (!rootEditableElement)
     return false;
+  DCHECK(hasComposition());
   PlainTextRange compositionRange =
       PlainTextRange::create(*rootEditableElement, *m_compositionRange);
   if (compositionRange.isNull())
     return false;
   int textStart = compositionRange.start();
 
   if (!replaceComposition(text))
     return false;
 
   int absoluteCaretPosition = computeAbsoluteCaretPosition(
@@ skipping 863 matching lines @@
   return WebTextInputTypeNone;
 }
 
 DEFINE_TRACE(InputMethodController) {
   visitor->trace(m_frame);
   visitor->trace(m_compositionRange);
   SynchronousMutationObserver::trace(visitor);
 }
 
 }  // namespace blink