Fix incorrect percentage top for positioned elements.

Source/core/layout/LayoutBox.cpp

Index: Source/core/layout/LayoutBox.cpp
diff --git a/Source/core/layout/LayoutBox.cpp b/Source/core/layout/LayoutBox.cpp
index b87d2138d1fcd54f189a0096ba5c5f9adb6514d1..be412169a0299a35952e526380087850078b30a3 100644
--- a/Source/core/layout/LayoutBox.cpp
+++ b/Source/core/layout/LayoutBox.cpp
@@ -2717,6 +2717,11 @@ LayoutUnit LayoutBox::availableLogicalHeightUsing(const Length& h, AvailableLogi
         return adjustContentBoxLogicalHeightForBoxSizing(newContentHeight);
     }
 
+    if (isLayoutBlock() && isOutOfFlowPositioned() && (heightType == IncludePadding)) {

[rune, 2015/03/13 12:49:13]

What happens if you pass IncludePadding with non-out-of-flow-positioned?

It doesn't look like you handle that at all. Should you just check for
IncludePadding and assert isLayoutBlock() && isOutOfFlowPositioned() instead?

[changseok, 2015/03/16 10:02:25]

IncludePadding is only for position:absolute. so none-out-of-flow-positioned
elements can't have it.
But I think you properly pointed out blinded problems. After rethinking the
lines and testing gecko, I found
this worked weirdly for some cases. Basically below recursive call of
containingBlockLogicalHeightForContent need to be changed with a determinate
method returning logical height. Otherwise viewport height (or page height, i,e
initialContainingBlock in the spec) would be eventually returned for some cases.

+        LayoutUnit availableHeight = containingBlockLogicalHeightForPositioned(this);
+        return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(h, availableHeight));
+    }
+
     // FIXME: This is wrong if the containingBlock has a perpendicular writing mode.
     LayoutUnit availableHeight = containingBlockLogicalHeightForContent(heightType);
     if (heightType == ExcludeMarginBorderPadding) {