Use correct offset when attribute auto is present

Source/core/dom/Position.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 61 matching lines @@
         if (!renderer)
             continue;
         if (!node->rendererIsEditable())
             continue;
         if ((renderer->isBox() && toRenderBox(renderer)->inlineBoxWrapper()) || (renderer->isText() && toRenderText(renderer)->firstTextBox()))
             return node;
     }
     return 0;
 }
 
+static bool hasDirectionAutoAttribute(Node* node)
+{
+    bool isAuto = node->selfOrAncestorHasDirAutoAttribute();
+    if (node->isInShadowTree())
+        isAuto = equalIgnoringCase(node->shadowHost()->fastGetAttribute(dirAttr), "auto");

[leviw_travelin_and_unemployed, 2014/06/02 18:00:29]

This seems specific to TextArea. If you're inside arbitrary Shadow DOM content,
you may not want this. At a minimum, it seems like if isAuto is true before this
line, the lack of this attribute on the shadowHost shouldn't blow it away, so
maybe you want if (!isAuto node->isInShadowTree())?

Or perhaps we should already be propagating the
selfOrAncestorHasDirAutoAttribute across shadow boundaries? I'd love to hear
from some of our shadow DOM experts.

[esprehn, 2014/06/02 18:06:13]

I don't think this is correct, what if you're multiple levels down?

[Habib Virji, 2014/06/03 16:35:57]

@levi: If I get some assistance about how to find information about shadow
elements in setHasDirAutoFlagRecursively, it will help in setting correct values
for selfOrAncestorHasDirAutoAttribute.  

I have upload a new patch which tries to return early to address above issue,
instead of checking shadowtree node. 

[Habib Virji, 2014/06/03 16:35:57]

@esprehn: i have upload a new patch which check multiple down, if dir auto
attribute is set. It is similar to approach in setHasDirAutoFlagRecursively but
instead looking for shadow nodes. 

+    return isAuto;
+}
+
 Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, LegacyEditingOffset offset)
     : m_anchorNode(anchorNode)
     , m_offset(offset.value())
     , m_anchorType(anchorTypeForLegacyEditingPosition(m_anchorNode.get(), m_offset))
     , m_isLegacyEditingPosition(true)
 {
     ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());
 }
 
 Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, AnchorType anchorType)
@@ skipping 1161 matching lines @@
         }
     } else {
         InlineBox* nextBox = inlineBox->nextLeafChildIgnoringLineBreak();
         if (!nextBox || nextBox->bidiLevel() < level) {
             // Right edge of a secondary run. Set to the left edge of the entire run.
             while (InlineBox* prevBox = inlineBox->prevLeafChildIgnoringLineBreak()) {
                 if (prevBox->bidiLevel() < level)
                     break;
                 inlineBox = prevBox;
             }
-            caretOffset = inlineBox->caretLeftmostOffset();
+            if (hasDirectionAutoAttribute(m_anchorNode.get()))
+                caretOffset = (inlineBox->bidiLevel() < level) ? inlineBox->caretLeftmostOffset() : inlineBox->caretRightmostOffset();
+            else
+                caretOffset = inlineBox->caretLeftmostOffset();
         } else if (nextBox->bidiLevel() > level) {
             // Left edge of a "tertiary" run. Set to the right edge of that run.
             while (InlineBox* tertiaryBox = inlineBox->nextLeafChildIgnoringLineBreak()) {
                 if (tertiaryBox->bidiLevel() <= level)
                     break;
                 inlineBox = tertiaryBox;
             }
             caretOffset = inlineBox->caretRightmostOffset();
         }
     }
@@ skipping 90 matching lines @@
     pos.showTreeForThis();
 }
 
 void showTree(const WebCore::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
 }
 
 #endif