Reimplement min-width: auto

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 a748a9193fd9f5b3d77750cec992380119c0db2d..a5550220c738f7901e0e33c93e5ae060610dbc84 100644
--- a/Source/core/layout/LayoutFlexibleBox.cpp
+++ b/Source/core/layout/LayoutFlexibleBox.cpp
@@ -117,7 +117,6 @@ void LayoutFlexibleBox::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidt
             maxLogicalWidth = std::max(maxPreferredLogicalWidth, maxLogicalWidth);
         }
     }
-
     maxLogicalWidth = std::max(minLogicalWidth, maxLogicalWidth);
 
     LayoutUnit scrollbarWidth = intrinsicScrollbarLogicalWidth();
@@ -339,6 +338,11 @@ Length LayoutFlexibleBox::flexBasisForChild(LayoutBox& child) const
     return flexLength;
 }
 
+bool LayoutFlexibleBox::percentageMainSizeIsResolvable()
+{
+    return isHorizontalFlow() ? hasDefiniteLogicalWidth() : hasDefiniteLogicalHeight();
+}
+
 LayoutUnit LayoutFlexibleBox::crossAxisExtentForChild(LayoutBox& child) const
 {
     return isHorizontalFlow() ? child.size().height() : child.size().width();
@@ -411,7 +415,7 @@ LayoutUnit LayoutFlexibleBox::computeMainAxisExtentForChild(LayoutBox& child, Si
         // We don't have to check for "auto" here - computeContentLogicalHeight will just return -1 for that case anyway.
         if (size.isIntrinsic())
             child.layoutIfNeeded();
-        return child.computeContentLogicalHeight(size, child.logicalHeight() - child.borderAndPaddingLogicalHeight()) + child.scrollbarLogicalHeight();
+        return child.computeContentLogicalHeight(sizeType, size, child.logicalHeight() - child.borderAndPaddingLogicalHeight()) + child.scrollbarLogicalHeight();
     }
     return child.computeLogicalWidthUsing(sizeType, size, contentLogicalWidth(), this) - child.borderAndPaddingLogicalWidth();
 }
@@ -827,19 +831,51 @@ void LayoutFlexibleBox::prepareOrderIteratorAndMargins()
     }
 }
 
-LayoutUnit LayoutFlexibleBox::adjustChildSizeForMinAndMax(LayoutBox& child, LayoutUnit childSize)
+LayoutUnit LayoutFlexibleBox::adjustChildSizeForMinAndMax(LayoutBox& child, LayoutUnit childSize, bool hasInfiniteLineLength)
 {
     Length max = isHorizontalFlow() ? child.style()->maxWidth() : child.style()->maxHeight();
+    LayoutUnit maxExtent = -1;
     if (max.isSpecifiedOrIntrinsic()) {
-        LayoutUnit maxExtent = computeMainAxisExtentForChild(child, MaxSize, max);
+        maxExtent = computeMainAxisExtentForChild(child, MaxSize, max);
         if (maxExtent != -1 && childSize > maxExtent)
             childSize = maxExtent;
     }
 
     Length min = isHorizontalFlow() ? child.style()->minWidth() : child.style()->minHeight();
     LayoutUnit minExtent = 0;
-    if (min.isSpecifiedOrIntrinsic())
+    if (min.isSpecifiedOrIntrinsic()) {
         minExtent = computeMainAxisExtentForChild(child, MinSize, min);
+        // computeMainAxisExtentForChild can return -1 when the child has a percentage
+        // min size, but we have an indefinite size in that axis.
+        minExtent = std::max(LayoutUnit(0), minExtent);
+    } else if (min.isAuto() && mainAxisOverflowForChild(child) == OVISIBLE) {
+        // css-flexbox section 4.5
+        LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent));
+        ASSERT(contentSize >= 0);
+        if (maxExtent != -1 && contentSize > maxExtent)
+            contentSize = maxExtent;
+
+        bool hasClampedSize = !childPreferredMainAxisContentExtentRequiresLayout(child, hasInfiniteLineLength);
+        if (hasClampedSize) {
+            Length flexBasis = flexBasisForChild(child);
+            bool flexBasisIsDefinite = flexBasis.isFixed() || (flexBasis.isPercent() && percentageMainSizeIsResolvable());
+            if (flexBasisIsDefinite) {
+                LayoutUnit resolvedFlexBasis = computeMainAxisExtentForChild(child, MainOrPreferredSize, flexBasis);
+                ASSERT(resolvedFlexBasis >= 0);
+                LayoutUnit clampedSize = resolvedFlexBasis;
+                if (maxExtent != -1 && clampedSize > maxExtent)
+                    clampedSize = maxExtent;
+
+                minExtent = std::min(clampedSize, contentSize);
+            } else {
+                minExtent = contentSize;
+            }
+        } else {
+            minExtent = contentSize;
+        }
+        // TODO(cbiesinger): Implement aspect ratio handling (here, transferred size)

[leviw_travelin_and_unemployed, 2015/04/02 22:14:36]

Tracking bug?

[cbiesinger, 2015/04/03 18:49:17]

Done.

+    }
+    ASSERT(minExtent >= 0);
     return std::max(childSize, minExtent);
 }
 
@@ -869,7 +905,7 @@ bool LayoutFlexibleBox::computeNextFlexLine(OrderedFlexItemList& orderedChildren
             + (isHorizontalFlow() ? child->marginWidth() : child->marginHeight());
         LayoutUnit childFlexBaseSize = childMainAxisExtent + childMainAxisMarginBorderPadding;
 
-        LayoutUnit childMinMaxAppliedMainAxisExtent = adjustChildSizeForMinAndMax(*child, childMainAxisExtent);
+        LayoutUnit childMinMaxAppliedMainAxisExtent = adjustChildSizeForMinAndMax(*child, childMainAxisExtent, hasInfiniteLineLength);
         LayoutUnit childHypotheticalMainSize = childMinMaxAppliedMainAxisExtent + childMainAxisMarginBorderPadding;
 
         if (isMultiline() && sumHypotheticalMainSize + childHypotheticalMainSize > lineBreakLength && lineHasInFlowItem)
@@ -925,7 +961,7 @@ bool LayoutFlexibleBox::resolveFlexibleLengths(FlexSign flexSign, const OrderedF
             if (std::isfinite(extraSpace))
                 childSize += LayoutUnit::fromFloatRound(extraSpace);
 
-            LayoutUnit adjustedChildSize = adjustChildSizeForMinAndMax(*child, childSize);
+            LayoutUnit adjustedChildSize = adjustChildSizeForMinAndMax(*child, childSize, hasInfiniteLineLength);
             childSizes.append(adjustedChildSize);
             usedFreeSpace += adjustedChildSize - preferredChildSize;
 
@@ -1052,6 +1088,13 @@ bool LayoutFlexibleBox::needToStretchChildLogicalHeight(LayoutBox& child) const
     return isHorizontalFlow() && child.style()->height().isAuto();
 }
 
+EOverflow LayoutFlexibleBox::mainAxisOverflowForChild(LayoutBox& child) const
+{
+    if (isHorizontalFlow())
+        return child.styleRef().overflowX();
+    return child.styleRef().overflowY();
+}
+
 void LayoutFlexibleBox::layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList& children, const Vector<LayoutUnit, 16>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, Vector<LineContext>& lineContexts, bool hasInfiniteLineLength)
 {
     ASSERT(childSizes.size() == children.size());