Blink doesn't honor percent heights on children of "align-self:stretch" flex items in a fixed-height

Source/core/rendering/RenderFlexibleBox.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1355 matching lines @@
 {
     if (!isColumnFlow() && child->style()->logicalHeight().isAuto()) {
         // FIXME: If the child has orthogonal flow, then it already has an override height set, so use it.
         if (!hasOrthogonalFlow(child)) {
             LayoutUnit heightBeforeStretching = needToStretchChildLogicalHeight(child) ? constrainedChildIntrinsicContentLogicalHeight(child) : child->logicalHeight();
             LayoutUnit stretchedLogicalHeight = heightBeforeStretching + availableAlignmentSpaceForChildBeforeStretching(lineCrossAxisExtent, child);
             ASSERT(!child->needsLayout());
             LayoutUnit desiredLogicalHeight = child->constrainLogicalHeightByMinMax(stretchedLogicalHeight, heightBeforeStretching - child->borderAndPaddingLogicalHeight());
 
             // FIXME: Can avoid laying out here in some cases. See https://webkit.org/b/87905.
             if (desiredLogicalHeight != child->logicalHeight()) {

[cbiesinger, 2014/06/25 04:14:32]

So I just realized there's another bug here. Even if desiredLogicalHeight ==
child->logicalHeight(), we still need to deal with the children of the child
here.

Testcase:
http://plexode.com/eval3/#s=aekVQXANJVQMbAx1yAXgePQN5GwFHTUZZHAGCnRYREVGiAYOm...
(green should be visible. first orange box should be 150px high. green box
should be 75px high.)

[harpreet.sk, 2014/06/25 14:43:08]

For the given case i think we need to do relayout of flex item. We need to add
an extra check other than desiredLogicalHeight != child->logicalHeight which
checks if the content of the flex item depends on its height or not. In new
solution i have added this check. I had added this test case in layout test as
well.

                 child->setOverrideLogicalContentHeight(desiredLogicalHeight - child->borderAndPaddingLogicalHeight());
+                child->setOverrideContainingBlockContentLogicalHeight(desiredLogicalHeight - child->borderAndPaddingLogicalHeight());
                 child->setLogicalHeight(0);
                 child->forceChildLayout();
+                child->clearOverrideContainingBlockContentLogicalHeight();
             }
         }
     } else if (isColumnFlow() && child->style()->logicalWidth().isAuto()) {
         // FIXME: If the child doesn't have orthogonal flow, then it already has an override width set, so use it.
         if (hasOrthogonalFlow(child)) {
             LayoutUnit childWidth = std::max<LayoutUnit>(0, lineCrossAxisExtent - crossAxisMarginExtentForChild(child));
             childWidth = child->constrainLogicalWidthByMinMax(childWidth, childWidth, this);
 
             if (childWidth != child->logicalWidth()) {
                 child->setOverrideLogicalContentWidth(childWidth - child->borderAndPaddingLogicalWidth());
@@ skipping 29 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(child, newOffset - originalOffset);
         }
     }
 }
 
 }