Blink does not respect input.selectionStart and input.selectionEnd for some cases

Source/core/html/HTMLTextFormControlElement.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 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 146 matching lines @@
     if (!placeholderElement() || placeholderValueChanged)
         updatePlaceholderText();
     HTMLElement* placeholder = placeholderElement();
     if (!placeholder)
         return;
     placeholder->setInlineStyleProperty(CSSPropertyVisibility, placeholderShouldBeVisible() ? CSSValueVisible : CSSValueHidden);
 }
 
 void HTMLTextFormControlElement::setSelectionStart(int start)
 {
-    setSelectionRange(start, max(start, selectionEnd()), selectionDirection());
+    setSelectionRange(start, max(start, selectionEndForJavascriptBindings()), selectionDirection());
 }
 
 void HTMLTextFormControlElement::setSelectionEnd(int end)
 {
-    setSelectionRange(min(end, selectionStart()), end, selectionDirection());
+    setSelectionRange(min(end, selectionStartForJavascriptBindings()), end, selectionDirection());
 }
 
 void HTMLTextFormControlElement::setSelectionDirection(const String& direction)
 {
     setSelectionRange(selectionStart(), selectionEnd(), direction);
 }
 
 void HTMLTextFormControlElement::select()
 {
     setSelectionRange(0, numeric_limits<int>::max(), SelectionHasNoDirection);
@@ skipping 95 matching lines @@
 
 void HTMLTextFormControlElement::setSelectionRange(int start, int end, TextFieldSelectionDirection direction)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
     if (!renderer() || !renderer()->isTextControl())
         return;
 
     end = max(end, 0);
     start = min(max(start, 0), end);
+    cacheSelection(start, end, direction);
 
-    if (!hasVisibleTextArea(renderer(), innerTextElement())) {
-        cacheSelection(start, end, direction);
+    if (!hasVisibleTextArea(renderer(), innerTextElement()))
         return;
-    }
     VisiblePosition startPosition = visiblePositionForIndex(start);
     VisiblePosition endPosition;
     if (start == end)
         endPosition = startPosition;
     else
         endPosition = visiblePositionForIndex(end);
 
     // startPosition and endPosition can be null position for example when
     // "-webkit-user-select: none" style attribute is specified.
     if (startPosition.isNotNull() && endPosition.isNotNull()) {
@@ skipping 31 matching lines @@
     RefPtrWillBeRawPtr<Range> range = Range::create(*indexPosition.document());
     range->setStart(innerTextElement(), 0, ASSERT_NO_EXCEPTION);
     range->setEnd(indexPosition.containerNode(), indexPosition.offsetInContainerNode(), ASSERT_NO_EXCEPTION);
     return TextIterator::rangeLength(range.get());
 }
 
 int HTMLTextFormControlElement::selectionStart() const
 {
     if (!isTextFormControl())
         return 0;
+    if (document().focusedElement() != this) {

[tkent, 2014/05/19 00:00:34]

We should not need to adjust the value on getting.

[harpreet.sk, 2014/05/19 11:16:52]

Only for given case we need to adjust value while getting:

We set input.selectionStart = 3 and input.selectionEnd = 5; input.value is empty
currently.

Now if we call selectionStart()/selectionEnd() it should return start/End as 0 (
all browsers return 0 ) but cache selection should still store 3 and 5 as
start/End for future.

Now if we set value of input as input.value = "Parsed" it should show
selectionStart/End as 3 and 5.

+        if (!innerTextValue().length())
+            return 0;
+        return m_cachedSelectionStart;
+    }
+
+    return computeSelectionStart();
+}
+
+int HTMLTextFormControlElement::selectionStartForJavascriptBindings() const
+{
+    if (!isTextFormControl())
+        return 0;
     if (document().focusedElement() != this)
         return m_cachedSelectionStart;
 
     return computeSelectionStart();
 }
 
 int HTMLTextFormControlElement::computeSelectionStart() const
 {
     ASSERT(isTextFormControl());
     LocalFrame* frame = document().frame();
     if (!frame)
         return 0;
 
     return indexForVisiblePosition(VisiblePosition(frame->selection().start()));
 }
 
 int HTMLTextFormControlElement::selectionEnd() const
 {
     if (!isTextFormControl())
         return 0;
+    if (document().focusedElement() != this) {
+        if (!innerTextValue().length())
+            return 0;
+        return m_cachedSelectionEnd;
+    }
+    return computeSelectionEnd();
+}
+
+int HTMLTextFormControlElement::selectionEndForJavascriptBindings() const
+{
+    if (!isTextFormControl())
+        return 0;
     if (document().focusedElement() != this)
         return m_cachedSelectionEnd;
+
     return computeSelectionEnd();
 }
 
 int HTMLTextFormControlElement::computeSelectionEnd() const
 {
     ASSERT(isTextFormControl());
     LocalFrame* frame = document().frame();
     if (!frame)
         return 0;
 
@@ skipping 95 matching lines @@
 void HTMLTextFormControlElement::restoreCachedSelection()
 {
     setSelectionRange(m_cachedSelectionStart, m_cachedSelectionEnd, m_cachedSelectionDirection);
 }
 
 void HTMLTextFormControlElement::selectionChanged(bool userTriggered)
 {
     if (!renderer() || !isTextFormControl())
         return;
 
-    // selectionStart() or selectionEnd() will return cached selection when this node doesn't have focus
-    cacheSelection(computeSelectionStart(), computeSelectionEnd(), computeSelectionDirection());
-
     if (LocalFrame* frame = document().frame()) {
         if (frame->selection().isRange() && userTriggered)
             dispatchEvent(Event::createBubble(EventTypeNames::select));
     }
 }
 
 void HTMLTextFormControlElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == placeholderAttr) {
         updatePlaceholderVisibility(true);
@@ skipping 157 matching lines @@
 
     return "ltr";
 }
 
 HTMLElement* HTMLTextFormControlElement::innerTextElement() const
 {
     return toHTMLElement(userAgentShadowRoot()->getElementById(ShadowElementNames::innerEditor()));
 }
 
 } // namespace Webcore