HTMLTextAreaElement.setSelectionRange should not change focus.

Source/core/html/HTMLTextAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 320 matching lines @@
 {
     updateValue();
     return m_value;
 }
 
 void HTMLTextAreaElement::setValue(const String& value, TextFieldEventBehavior eventBehavior)
 {
     RefPtrWillBeRawPtr<HTMLTextAreaElement> protector(this);
     setValueCommon(value, eventBehavior);
     m_isDirty = true;
-    setNeedsValidityCheck();
     if (document().focusedElement() == this)
         document().frameHost()->chrome().client().didUpdateTextOfFocusedElementByNonUserInput();
 }
 
 void HTMLTextAreaElement::setNonDirtyValue(const String& value)
 {
-    setValueCommon(value, DispatchNoEvent);
+    setValueCommon(value, DispatchNoEvent, ChangeSelection);
     m_isDirty = false;
-    setNeedsValidityCheck();
 }
 
-void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventBehavior eventBehavior)
+void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventBehavior eventBehavior, SelectionOption selectionOption)
 {
     // Code elsewhere normalizes line endings added by the user via the keyboard or pasting.
     // We normalize line endings coming from JavaScript here.
     String normalizedValue = newValue.isNull() ? "" : newValue;
     normalizedValue.replace("\r\n", "\n");
     normalizedValue.replace('\r', '\n');
 
-    // Return early because we don't want to move the caret or trigger other side effects
-    // when the value isn't changing. This matches Firefox behavior, at least.
-    if (normalizedValue == value())
+    // Return early because we don't want to trigger other side effects
+    // when the value isn't changing.
+    // FIXME: Simple early return doesn't match the Firefox ever.
+    // Remove these lines.
+    if (normalizedValue == value()) {
+        if (selectionOption == ChangeSelection) {
+            setNeedsValidityCheck();
+            if (isFinishedParsingChildren()) {
+                // Set the caret to the end of the text value except for initialize.
+                unsigned endOfString = m_value.length();
+                setSelectionRange(endOfString, endOfString, SelectionHasNoDirection, NotChangeSelection);
+            }
+        }
         return;
+    }
 
     m_value = normalizedValue;
     setInnerEditorValue(m_value);
     if (eventBehavior == DispatchNoEvent)
         setLastChangeWasNotUserEdit();
     updatePlaceholderVisibility(false);
     setNeedsStyleRecalc(SubtreeStyleChange);
     m_suggestedValue = String();
-
-    // Set the caret to the end of the text value.
-    if (document().focusedElement() == this) {
+    setNeedsValidityCheck();

[yoichio, 2014/07/24 03:06:07]

Moved from setSelectionRange, setValue and setNonDirtyValue.

+    if (isFinishedParsingChildren()) {
+        // Set the caret to the end of the text value except for initialize.
         unsigned endOfString = m_value.length();
-        setSelectionRange(endOfString, endOfString);
+        setSelectionRange(endOfString, endOfString, SelectionHasNoDirection, NotChangeSelection);
     }
 
     notifyFormStateChanged();
     if (eventBehavior == DispatchNoEvent) {
         setTextAsOfLastFormControlChangeEvent(normalizedValue);
     } else {
         if (eventBehavior == DispatchInputAndChangeEvent)
             dispatchFormControlInputEvent();
         dispatchFormControlChangeEvent();
     }
@@ skipping 168 matching lines @@
 {
     return true;
 }
 
 bool HTMLTextAreaElement::supportsAutofocus() const
 {
     return true;
 }
 
 }