Only pass nodes to layout for restyling that are actually in the document.

1 files changed, 2 insertions, 1 deletions

diff --git a/components/script/layout_wrapper.rs b/components/script/layout_wrapper.rs
index 25150d60dfe..5576648b84d 100644
--- a/components/script/layout_wrapper.rs
+++ b/components/script/layout_wrapper.rs
@@ -37,7 +37,7 @@ use dom::bindings::js::LayoutJS;
 use dom::characterdata::LayoutCharacterDataHelpers;
 use dom::document::{Document, LayoutDocumentHelpers, PendingRestyle};
 use dom::element::{Element, LayoutElementHelpers, RawLayoutElementHelpers};
-use dom::node::{CAN_BE_FRAGMENTED, DIRTY_ON_VIEWPORT_SIZE_CHANGE, HAS_DIRTY_DESCENDANTS};
+use dom::node::{CAN_BE_FRAGMENTED, DIRTY_ON_VIEWPORT_SIZE_CHANGE, HAS_DIRTY_DESCENDANTS, IS_IN_DOC};
 use dom::node::{LayoutNodeHelpers, Node};
 use dom::text::Text;
 use gfx_traits::ByteIndex;
@@ -404,6 +404,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     }
 
     unsafe fn set_dirty_descendants(&self) {
+        debug_assert!(self.as_node().node.get_flag(IS_IN_DOC));
         self.as_node().node.set_flag(HAS_DIRTY_DESCENDANTS, true)
     }