[css-grid] Fix definite/indefinite size detection on block axis

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

 /*
  * Copyright (C) 2013 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 216 matching lines @@
         // Calculate the non-auto content box height, or set it to 0 if it's auto. We need to know
         // this before layout, so that we can figure out where to insert column breaks. We also
         // treat LayoutView (which may be paginated, which uses the multicol implmentation) as
         // having non-auto height, since its height is deduced from the viewport height. We use
         // computeLogicalHeight() to calculate the content box height. That method will clamp
         // against max-height and min-height. Since we're now at the beginning of layout, and we
         // don't know the actual height of the content yet, only call that method when height is
         // definite, or we might fool ourselves into believing that columns have a definite height
         // when they in fact don't.
         LayoutUnit columnHeight;
-        if (hasDefiniteLogicalHeight() || isLayoutView()) {
+        if (!firstInFlowChildBox() || firstInFlowChildBox()->percentageLogicalHeightIsResolvable() || isLayoutView()) {

[cbiesinger, 2016/06/07 20:21:12]

Can you add a comment here explaining the firstInFlowChildBox() logic, so it's
clearer to future readers? Same in LayoutGrid

[Manuel Rego, 2016/06/08 12:10:24]

Yeah, I'll add a comment.

             LogicalExtentComputedValues computedValues;
             computeLogicalHeight(LayoutUnit(), logicalTop(), computedValues);
             columnHeight = computedValues.m_extent - borderAndPaddingLogicalHeight() - scrollbarLogicalHeight();
         }
         pageLogicalHeightChanged = columnHeight != flowThread->columnHeightAvailable();
         flowThread->setColumnHeightAvailable(std::max(columnHeight, LayoutUnit()));
     } else if (isLayoutFlowThread()) {
         LayoutFlowThread* flowThread = toLayoutFlowThread(this);
 
         // FIXME: This is a hack to always make sure we have a page logical height, if said height
@@ skipping 3579 matching lines @@
             if (!rect.isEmpty())
                 rects.append(rect);
         }
     }
 
     if (inlineElementContinuation)
         inlineElementContinuation->addOutlineRects(rects, additionalOffset + (inlineElementContinuation->containingBlock()->location() - location()), includeBlockOverflows);
 }
 
 } // namespace blink