BR styled clear is ignored while partially relayouting.

Source/core/layout/LayoutBlockFlowLine.cpp

Index: Source/core/layout/LayoutBlockFlowLine.cpp
diff --git a/Source/core/layout/LayoutBlockFlowLine.cpp b/Source/core/layout/LayoutBlockFlowLine.cpp
index 90671e46dfb6dd6edd0603c695ac1853c4caf191..d0e70caa2ce2b055049c8664e2afa3857ffba947 100644
--- a/Source/core/layout/LayoutBlockFlowLine.cpp
+++ b/Source/core/layout/LayoutBlockFlowLine.cpp
@@ -1563,6 +1563,9 @@ void LayoutBlockFlow::layoutInlineChildren(bool relayoutChildren, LayoutUnit& pa
             if (!layoutState.hasInlineChild() && o->isInline())
                 layoutState.setHasInlineChild(true);
 
+            if (o->isBR() && o->style()->clear() != CNONE)
+                layoutState.setContainsBRWithClear(true);
+
             if (o->isReplaced() || o->isFloating() || o->isOutOfFlowPositioned()) {
                 LayoutBox* box = toLayoutBox(o);
 
@@ -1858,6 +1861,11 @@ bool LayoutBlockFlow::matchedEndLine(LineLayoutState& layoutState, const InlineB
     if (resolver.position() == endLineStart) {
         if (resolver.status() != endLineStatus)
             return false;
+
+        // Be careful not to ignore <br> with clear style for partial layout where the block
+        // contains floats. It might mislead height of the block into being shorter than expected.

[leviw_travelin_and_unemployed, 2015/05/19 21:29:52]

Can we word this better?

Specifically mention the bug instead of saying "might" and "be careful"

[changseok, 2015/05/20 14:22:24]

Updated.

+        if (layoutState.containsBRWithClear() && containsFloats())
+            return false;
         return checkPaginationAndFloatsAtEndLine(layoutState);
     }