Flexbox: negatively stretching a flexbox should have border + padding as a minimum

Source/core/layout/LayoutFlexibleBox.cpp

Index: Source/core/layout/LayoutFlexibleBox.cpp
diff --git a/Source/core/layout/LayoutFlexibleBox.cpp b/Source/core/layout/LayoutFlexibleBox.cpp
index a30f5d91022e034adc4ec194e96b3591ff85a4cb..9424b183924f0967bbb4cff9bab94ec0d012b348 100644
--- a/Source/core/layout/LayoutFlexibleBox.cpp
+++ b/Source/core/layout/LayoutFlexibleBox.cpp
@@ -1343,7 +1343,7 @@ void LayoutFlexibleBox::applyStretchAlignmentToChild(LayoutBox& child, LayoutUni
         // 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);
+            LayoutUnit stretchedLogicalHeight = std::max(child.borderAndPaddingLogicalHeight(), heightBeforeStretching + availableAlignmentSpaceForChildBeforeStretching(lineCrossAxisExtent, child));
             ASSERT(!child.needsLayout());
             LayoutUnit desiredLogicalHeight = child.constrainLogicalHeightByMinMax(stretchedLogicalHeight, heightBeforeStretching - child.borderAndPaddingLogicalHeight());