[css-flexbox] Add test case for definite widths

third_party/WebKit/Source/core/layout/LayoutBox.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 4157 matching lines @@
         return;
 
     if (!hasSelfVisualOverflow() && contentsVisualOverflowRect().isEmpty()) {
         clearAllOverflows();
         return;
     }
 
     m_overflow->setLayoutOverflow(noOverflowRect());
 }
 
 static bool logicalWidthIsResolvable(const LayoutBox& layoutBox)

[mstensho (USE GERRIT), 2016/05/03 12:08:52]

Not for this CL, but I think this function should be refactored. It's hard to
follow the logic. First we walk the ancestry until we find something
interesting. Then there's pretty much duplicated code that examines the
interesting object and returns true or false.

 {
     const LayoutBox* box = &layoutBox;
     while (!box->isLayoutView() && !box->isFloatingOrOutOfFlowPositioned()
         && (box->style()->logicalWidth().isAuto() || box->isAnonymousBlock())
+        && !isStretchingColumnFlexItem(box)
         && !box->hasOverrideContainingBlockLogicalWidth())
         box = box->containingBlock();
 
     if (box->style()->logicalWidth().isFixed())
         return true;
     if (box->isLayoutView())
         return true;
     if (box->isOutOfFlowPositioned() && !box->style()->logicalLeft().isAuto() && !box->style()->logicalRight().isAuto())
         return true;
+    if (isStretchingColumnFlexItem(box))

[mstensho (USE GERRIT), 2016/05/03 12:08:52]

logicalWidthIsResolvable(), isn't that about the size being definite or not?
I.e. https://drafts.csswg.org/css-sizing-3/#definite ?

Some flexbox extensions to the definition of "definite size" here:
https://drafts.csswg.org/css-flexbox/#definite-sizes

But all widths and heights of flexboxes and flex items in the test case are
auto, so there's nothing definite here, is there?

Reduced test:

<p>There should be no red or yellow here.</p>
<div id="stf" style="float:left; background:yellow;">
    <div id="outerFlex" style="display:flex; flex-direction:column;">
        <div id="innerFlex" style="display:flex; background:red;">
            <div id="elm" style="width:100%; background:green;">xxxxx</div>
        </div>
    </div>
    <div style="width:20em;"></div>
</div>

Without the patch, I see that #innerFlex gets the correct width. It's a flex
item in #outerFlex, and its width is the cross size, which by default is
stretched. #elm is a flex item in #innerFlex, and its main size is 100%. Its
containing block is #innerFlex, so why not just set it to 100% of the width of
#innerFlex? Why ask the ancestry for permission? Fear of cyclic dependencies?

+        return true;
     if (box->hasOverrideContainingBlockLogicalWidth())
         return box->overrideContainingBlockContentLogicalWidth() != -1;
     if (box->style()->logicalWidth().hasPercent())
         return logicalWidthIsResolvable(*box->containingBlock());
 
     return false;
 }
 
 bool LayoutBox::hasDefiniteLogicalWidth() const
 {
@@ skipping 549 matching lines @@
 
 void LayoutBox::clearPercentHeightDescendants()
 {
     for (LayoutObject* curr = slowFirstChild(); curr; curr = curr->nextInPreOrder(this)) {
         if (curr->isBox())
             toLayoutBox(curr)->removeFromPercentHeightContainer();
     }
 }
 
 } // namespace blink