1 files changed, 16 insertions, 2 deletions
diff --git a/src/components/main/layout/layout_task.rs b/src/components/main/layout/layout_task.rs
index 8a52d93b284..0fdacec78ad 100644
--- a/src/components/main/layout/layout_task.rs
+++ b/src/components/main/layout/layout_task.rs
@@ -212,7 +212,11 @@ impl<'a> PostorderFlowTraversal for AssignHeightsAndStoreOverflowTraversal<'a> {
     #[inline]
     fn process(&mut self, flow: &mut Flow) -> bool {
         flow.assign_height(self.layout_context);
-        flow.store_overflow(self.layout_context);
+        // Skip store-overflow for absolutely positioned flows. That will be
+        // done in a separate traversal.
+        if !flow.is_store_overflow_delayed() {
+            flow.store_overflow(self.layout_context);
+        }
         true
     }
 
@@ -427,7 +431,17 @@ impl LayoutTask {
             None => fail!("no layout data for root node"),
         };
         let mut flow = match result {
-            FlowConstructionResult(flow) => flow,
+            FlowConstructionResult(mut flow, abs_descendants, fixed_descendants) => {
+                // Note: Assuming that the root has display 'static' (as per
+                // CSS Section 9.3.1). Otherwise, if it were absolutely
+                // positioned, it would return a reference to itself in
+                // `abs_descendants` and would lead to a circular reference.
+                // Set Root as CB for any remaining absolute descendants.
+                flow.set_abs_descendants(abs_descendants);
+                // Set Root as CB for all fixed descendants.
+                flow.set_fixed_descendants(fixed_descendants);
+                flow
+            }
             _ => fail!("Flow construction didn't result in a flow at the root of the tree!"),
         };
         flow.mark_as_root();