Resolve direction correctly when dir attribute is not in a defined state

Source/core/html/HTMLElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004-2008, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * 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 170 matching lines @@
     } else if (name == draggableAttr) {
         if (equalIgnoringCase(value, "true")) {
             addPropertyToPresentationAttributeStyle(style, CSSPropertyWebkitUserDrag, CSSValueElement);
             addPropertyToPresentationAttributeStyle(style, CSSPropertyWebkitUserSelect, CSSValueNone);
         } else if (equalIgnoringCase(value, "false"))
             addPropertyToPresentationAttributeStyle(style, CSSPropertyWebkitUserDrag, CSSValueNone);
     } else if (name == dirAttr) {
         if (equalIgnoringCase(value, "auto"))
             addPropertyToPresentationAttributeStyle(style, CSSPropertyUnicodeBidi, unicodeBidiAttributeForDirAuto(this));
         else {
             if (isValidDirAttribute(value))

[tkent, 2014/09/12 06:33:55]

If |value| is "auto", this code sets it to direction property.  Does it conform
to the standard?

[Sunil Ratnu, 2014/09/12 07:16:12]

I don't think the flow will come here for value 'auto' because it is in the else
block. Do tell me if i am missing something. Thanks!

[tkent, 2014/11/07 01:01:53]

Why is it in the else block?  Did you look at the isValidDirAttribute code?

[Sunil Ratnu, 2014/11/12 13:49:32]

Yes, I did take a look at the isValidDirAttribute and it qualifies "ltr", "rtl",
"auto" as valid dir attributes.
The css direction property specifies the text direction/writing direction and it
 can take values of "ltr", "rtl", "initial" and "inherit", so we do not want to
set an "auto" value (i.e. and invalid value for css direction property) to the
css direction property, hence, it is in the else block.

[tkent, 2014/11/19 03:32:19]

Ah, you're right.  We check "auto" at line 188.  Sorry for the confusion.

                 addPropertyToPresentationAttributeStyle(style, CSSPropertyDirection, value);
-            else
-                addPropertyToPresentationAttributeStyle(style, CSSPropertyDirection, "ltr");
             if (!hasTagName(bdiTag) && !hasTagName(bdoTag) && !hasTagName(outputTag))
                 addPropertyToPresentationAttributeStyle(style, CSSPropertyUnicodeBidi, CSSValueEmbed);
         }
     } else if (name.matches(XMLNames::langAttr))
         mapLanguageAttributeToLocale(value, style);
     else if (name == langAttr) {
         // xml:lang has a higher priority than lang.
         if (!fastHasAttribute(XMLNames::langAttr))
             mapLanguageAttributeToLocale(value, style);
     } else
@@ skipping 471 matching lines @@
 {
     if (!(selfOrAncestorHasDirAutoAttribute() && hasDirectionAuto())) {
         isAuto = false;
         return LTR;
     }
 
     isAuto = true;
     return directionality();
 }
 
+// FIXME: Implement directionality for input type='tel' when it is supported

[tkent, 2014/11/19 03:38:34]

type=tel is supported by Google Chrome, IE, Firefox, and Safari.

+// [Currently it is not supported in any of the browsers].
+// Spec: http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#the-directionality
+TextDirection HTMLElement::determineDirection() const
+{
+    for (const HTMLElement* element = this; element; element = Traversal<HTMLElement>::firstAncestor(*element)) {
+        const AtomicString& dirAttributeValue = element->fastGetAttribute(dirAttr);
+        if (dirAttributeValue.isNull())
+            continue;
+
+        if (equalIgnoringCase(dirAttributeValue, "rtl"))
+            return RTL;
+
+        if (equalIgnoringCase(dirAttributeValue, "ltr"))
+            return LTR;
+
+        if (equalIgnoringCase(dirAttributeValue, "auto")) {
+            bool isAuto;
+            return element->directionalityIfhasDirAutoAttribute(isAuto);
+        }
+    }
+
+    return LTR;
+}
+
+// FIXME: This implementation deviates from the spec in case of 'textarea' having 'auto' attribute.
+// Spec: http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#the-directionality
 TextDirection HTMLElement::directionality(Node** strongDirectionalityTextNode) const
 {
     if (isHTMLInputElement(*this)) {
         HTMLInputElement* inputElement = toHTMLInputElement(const_cast<HTMLElement*>(this));
         bool hasStrongDirectionality;
         TextDirection textDirection = determineDirectionality(inputElement->value(), hasStrongDirectionality);
         if (strongDirectionalityTextNode)
             *strongDirectionalityTextNode = hasStrongDirectionality ? inputElement : 0;
         return textDirection;
     }
@@ skipping 298 matching lines @@
 #ifndef NDEBUG
 
 // For use in the debugger
 void dumpInnerHTML(blink::HTMLElement*);
 
 void dumpInnerHTML(blink::HTMLElement* element)
 {
     printf("%s\n", element->innerHTML().ascii().data());
 }
 #endif