[css-grid] Fix indefinite height detection

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

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 04c701c370f4fcc0f87c82d3f54ac3fae6a5d6d9..a46051ae99e14ff2d40693c6eb8b561cd9ddf298 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -1872,4 +1872,56 @@ void LayoutBlock::checkPositionedObjectsNeedLayout()
 
 #endif
 
+LayoutUnit LayoutBlock::availableLogicalHeightForPercentageComputation(const LayoutBlock& block)

[jfernandez, 2016/07/22 11:26:37]

Shouldn't be const ?

[Manuel Rego, 2016/07/22 13:05:37]

It's static so you cannot modify anything,
but once I convert it in a member function I'll mark it as const sure.

+{
+    LayoutUnit availableHeight(-1);
+
+    const ComputedStyle& style = block.styleRef();
+
+    // A positioned element that specified both top/bottom or that specifies height should be treated as though it has a height
+    // explicitly specified that can be used for any percentage computations.
+    bool isOutOfFlowPositionedWithSpecifiedHeight = block.isOutOfFlowPositioned() && (!style.logicalHeight().isAuto() || (!style.logicalTop().isAuto() && !style.logicalBottom().isAuto()));
+
+    LayoutUnit stretchedFlexHeight(-1);
+    if (block.isFlexItem())
+        stretchedFlexHeight = toLayoutFlexibleBox(block.parent())->childLogicalHeightForPercentageResolution(block);
+
+    if (stretchedFlexHeight != LayoutUnit(-1)) {
+        availableHeight = stretchedFlexHeight;
+    } else if (block.isGridItem() && block.hasOverrideLogicalContentHeight()) {
+        availableHeight = block.overrideLogicalContentHeight();
+    } else if (style.logicalHeight().isFixed()) {
+        LayoutUnit contentBoxHeight = block.adjustContentBoxLogicalHeightForBoxSizing(style.logicalHeight().value());
+        availableHeight = block.constrainContentBoxLogicalHeightByMinMax(
+            contentBoxHeight - block.scrollbarLogicalHeight(), LayoutUnit(-1)).clampNegativeToZero();
+    } else if (style.logicalHeight().hasPercent() && !isOutOfFlowPositionedWithSpecifiedHeight) {
+        // We need to recur and compute the percentage height for our containing block.

[jfernandez, 2016/07/22 11:26:37]

I don't understand this comment. Could you please elaborate ? 

[Manuel Rego, 2016/07/22 13:05:37]

This comment was already in computePercentageLogicalHeight().
Bur probably it doesn't make sense to move it  here, the thing is
when you're computing the percentage height on a element,
if your containing block has a percentage, you need to compute
that percentage first, before being able to resolve yours.

+        LayoutUnit heightWithScrollbar = block.computePercentageLogicalHeight(style.logicalHeight());
+        if (heightWithScrollbar != -1) {
+            LayoutUnit contentBoxHeightWithScrollbar = block.adjustContentBoxLogicalHeightForBoxSizing(heightWithScrollbar);
+            // We need to adjust for min/max height because this method does not
+            // handle the min/max of the current block, its caller does. So the
+            // return value from the recursive call will not have been adjusted
+            // yet.
+            LayoutUnit contentBoxHeight = block.constrainContentBoxLogicalHeightByMinMax(contentBoxHeightWithScrollbar - block.scrollbarLogicalHeight(), LayoutUnit(-1));
+            availableHeight = std::max(LayoutUnit(), contentBoxHeight);
+        }
+    } else if (isOutOfFlowPositionedWithSpecifiedHeight) {
+        // Don't allow this to affect the block' size() member variable, since this
+        // can get called while the block is still laying out its kids.
+        LogicalExtentComputedValues computedValues;
+        block.computeLogicalHeight(block.logicalHeight(), LayoutUnit(), computedValues);
+        availableHeight = computedValues.m_extent - block.borderAndPaddingLogicalHeight() - block.scrollbarLogicalHeight();
+    } else if (block.isLayoutView()) {
+        availableHeight = toLayoutView(block).viewLogicalHeightForPercentages();
+    }
+
+    return availableHeight;
+}
+
+bool LayoutBlock::hasDefiniteLogicalHeight() const
+{
+    return availableLogicalHeightForPercentageComputation(*this) != LayoutUnit(-1);
+}
+
 } // namespace blink