HTMLTextAreaElement.setSelectionRange should not change focus.

Source/core/html/HTMLTextAreaElement.cpp

Index: Source/core/html/HTMLTextAreaElement.cpp
diff --git a/Source/core/html/HTMLTextAreaElement.cpp b/Source/core/html/HTMLTextAreaElement.cpp
index fd7ad6434bc60392e35ebe11871ee0c35cb2c472..ff34db902f8a27abda936542d8531f09308037fa 100644
--- a/Source/core/html/HTMLTextAreaElement.cpp
+++ b/Source/core/html/HTMLTextAreaElement.cpp
@@ -220,6 +220,8 @@ bool HTMLTextAreaElement::appendFormData(FormDataList& encoding, bool)
 void HTMLTextAreaElement::resetImpl()
 {
     setNonDirtyValue(defaultValue());
+    unsigned endOfString = m_value.length();
+    setSelectionRange(endOfString, endOfString, SelectionHasNoDirection, NotChangeSelection);

[tkent, 2014/07/24 01:04:22]

Why only resetImpl() has this though childrenChanged and setDefaultValue don't?

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

I found also childrenChanged and setDefaultValue needs set selection to end even
if resetting a same value.
Thus I add extra setSelectionRange calling into the early return point in
setValueCommon. 

 }
 
 bool HTMLTextAreaElement::hasCustomFocusLogic() const
@@ -371,10 +373,10 @@ void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventB
     setNeedsStyleRecalc(SubtreeStyleChange);
     m_suggestedValue = String();
 
-    // Set the caret to the end of the text value.
-    if (document().focusedElement() == this) {
+    if (renderer()) {

[tkent, 2014/07/24 01:04:22]

Checking renderer() is not correct.  We should call setSelectionRange even if
the element has display:none.  We should check isFinishedParsingChildren().

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

Done.

+        // 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();