Consider text alignment and direction when computing the left offset for horizontal writing modes.

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 3432 matching lines @@
     }
 }
 
 static void computeLogicalLeftPositionedOffset(LayoutUnit& logicalLeftPos, const RenderBox* child, LayoutUnit logicalWidthValue, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalWidth)
 {
     // Deal with differing writing modes here.  Our offset needs to be in the containing block's coordinate space. If the containing block is flipped
     // along this axis, then we need to flip the coordinate.  This can only happen if the containing block is both a flipped mode and perpendicular to us.
     if (containerBlock->isHorizontalWritingMode() != child->isHorizontalWritingMode() && containerBlock->style()->isFlippedBlocksWritingMode()) {
         logicalLeftPos = containerLogicalWidth - logicalWidthValue - logicalLeftPos;
         logicalLeftPos += (child->isHorizontalWritingMode() ? containerBlock->borderRight() : containerBlock->borderBottom());
-    } else
-        logicalLeftPos += (child->isHorizontalWritingMode() ? containerBlock->borderLeft() : containerBlock->borderTop());
+    } else if (child->isHorizontalWritingMode()) {
+        RenderStyle* blockStyle = containerBlock->style();
+        bool containerBlockIsLTR = isLeftToRightDirection(blockStyle->direction());
+        ETextAlign textAlignForContainerBlock = containerBlock->simplifiedTextAlign(blockStyle->textAlign());
+        if (containerBlockIsLTR && textAlignForContainerBlock == RIGHT) {
+            logicalLeftPos = containerLogicalWidth - (logicalWidthValue + child->borderLogicalWidth() + child->style()->logicalRight().value());
+            logicalLeftPos += containerBlock->borderLogicalRight();
+        } else if (!containerBlockIsLTR && textAlignForContainerBlock == LEFT) {
+            logicalLeftPos += containerBlock->borderAndPaddingLogicalLeft() + logicalWidthValue;
+        } else {
+            logicalLeftPos += containerBlock->borderLeft();
+        }
+    } else {
+        logicalLeftPos += containerBlock->borderTop();
+    }
 }
 
 void RenderBox::shrinkToFitWidth(const LayoutUnit availableSpace, const LayoutUnit logicalLeftValue, const LayoutUnit bordersPlusPadding, LogicalExtentComputedValues& computedValues) const
 {
     // FIXME: would it be better to have shrink-to-fit in one step?
     LayoutUnit preferredWidth = maxPreferredLogicalWidth() - bordersPlusPadding;
     LayoutUnit preferredMinWidth = minPreferredLogicalWidth() - bordersPlusPadding;
     LayoutUnit availableWidth = availableSpace - logicalLeftValue;
     computedValues.m_extent = min(max(preferredMinWidth, availableWidth), preferredWidth);
 }
@@ skipping 1448 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore