[CSS Grid Layout] Unknown grid area should compute to 'auto'

Source/core/css/resolver/StyleAdjuster.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 345 matching lines @@
     // FIXME: when dropping the -webkit prefix on transform-style, we should also have opacity < 1 cause flattening.
     if (style->preserves3D() && (style->overflowX() != OVISIBLE
         || style->overflowY() != OVISIBLE
         || style->hasFilter()))
         style->setTransformStyle3D(TransformStyle3DFlat);
 
     // Seamless iframes behave like blocks. Map their display to inline-block when marked inline.
     if (e && e->hasTagName(iframeTag) && style->display() == INLINE && toHTMLIFrameElement(e)->shouldDisplaySeamlessly())
         style->setDisplay(INLINE_BLOCK);
 
-    adjustGridItemPosition(style);
+    adjustGridItemPosition(style, parentStyle);
 
     if (e && e->isSVGElement()) {
         // Spec: http://www.w3.org/TR/SVG/masking.html#OverflowProperty
         if (style->overflowY() == OSCROLL)
             style->setOverflowY(OHIDDEN);
         else if (style->overflowY() == OAUTO)
             style->setOverflowY(OVISIBLE);
 
         if (style->overflowX() == OSCROLL)
             style->setOverflowX(OHIDDEN);
         else if (style->overflowX() == OAUTO)
             style->setOverflowX(OVISIBLE);
 
         // Only the root <svg> element in an SVG document fragment tree honors css position
         if (!(e->hasTagName(SVGNames::svgTag) && e->parentNode() && !e->parentNode()->isSVGElement()))
             style->setPosition(RenderStyle::initialPosition());
 
         // RenderSVGRoot handles zooming for the whole SVG subtree, so foreignObject content should
         // not be scaled again.
         if (e->hasTagName(SVGNames::foreignObjectTag))
             style->setEffectiveZoom(RenderStyle::initialZoom());
     }
 }
 
-void StyleAdjuster::adjustGridItemPosition(RenderStyle* style) const
+void StyleAdjuster::adjustGridItemPosition(RenderStyle* style, RenderStyle* parentStyle) const
 {
+    const GridPosition& columnStartPosition = style->gridColumnStart();
+    const GridPosition& columnEndPosition = style->gridColumnEnd();
+    const GridPosition& rowStartPosition = style->gridRowStart();
+    const GridPosition& rowEndPosition = style->gridRowEnd();
+
     // If opposing grid-placement properties both specify a grid span, they both compute to ‘auto’.
-    if (style->gridColumnStart().isSpan() && style->gridColumnEnd().isSpan()) {
+    if (columnStartPosition.isSpan() && columnEndPosition.isSpan()) {
         style->setGridColumnStart(GridPosition());
         style->setGridColumnEnd(GridPosition());
     }
 
-    if (style->gridRowStart().isSpan() && style->gridRowEnd().isSpan()) {
+    if (rowStartPosition.isSpan() && rowEndPosition.isSpan()) {
         style->setGridRowStart(GridPosition());
         style->setGridRowEnd(GridPosition());
     }
+
+    // Unknown named grid area compute to 'auto'.
+    const NamedGridAreaMap& map = parentStyle->namedGridArea();
+
+#define CLEAR_UNKNOWN_NAMED_AREA(prop, Prop) \
+    if (prop.isNamedGridArea() && !map.contains(prop.namedGridLine())) \
+        style->setGrid##Prop(GridPosition());
+
+    CLEAR_UNKNOWN_NAMED_AREA(columnStartPosition, ColumnStart);
+    CLEAR_UNKNOWN_NAMED_AREA(columnEndPosition, ColumnEnd);
+    CLEAR_UNKNOWN_NAMED_AREA(rowStartPosition, RowStart);
+    CLEAR_UNKNOWN_NAMED_AREA(rowEndPosition, RowEnd);
 }
 
-
-
 }