From 6b981039d083e66445c1f8df65f6025febdb8238 Mon Sep 17 00:00:00 2001
From: Ms2ger <Ms2ger@gmail.com>
Date: Wed, 29 Jun 2016 09:46:45 +0200
Subject: [PATCH] Avoid the Vec reversal in DisplayList::hit_test.

---
 components/gfx/display_list/mod.rs | 6 ++----
 components/layout/query.rs         | 1 +
 components/layout_thread/lib.rs    | 2 +-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/components/gfx/display_list/mod.rs b/components/gfx/display_list/mod.rs
index 988bfa5af96..25b7c46075f 100644
--- a/components/gfx/display_list/mod.rs
+++ b/components/gfx/display_list/mod.rs
@@ -480,9 +480,8 @@ impl DisplayList {
             &draw_target, &stacking_context.filters, stacking_context.blend_mode);
     }
 
-    /// Places all nodes containing the point of interest into `result`, topmost first. Respects
-    /// the `pointer-events` CSS property If `topmost_only` is true, stops after placing one node
-    /// into the list. `result` must be empty upon entry to this function.
+    /// Return all nodes containing the point of interest, bottommost first,
+    /// and respecting the `pointer-events` CSS property.
     pub fn hit_test(&self, point: &Point2D<Au>, scroll_offsets: &ScrollOffsetMap)
                     -> Vec<DisplayItemMetadata> {
         let mut traversal = DisplayListTraversal {
@@ -492,7 +491,6 @@ impl DisplayList {
         };
         let mut result = Vec::new();
         self.root_stacking_context.hit_test(&mut traversal, point, scroll_offsets, &mut result);
-        result.reverse();
         result
     }
 }
diff --git a/components/layout/query.rs b/components/layout/query.rs
index f5735c97877..ea22bd966d5 100644
--- a/components/layout/query.rs
+++ b/components/layout/query.rs
@@ -150,6 +150,7 @@ impl LayoutRPC for LayoutRPCImpl {
         };
 
         nodes_from_point_list.iter()
+           .rev()
            .map(|metadata| metadata.node.to_untrusted_node_address())
            .collect()
     }
diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index 6d46500621b..b33a5c56eb1 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -1160,7 +1160,7 @@ impl LayoutThread {
                                         .as_ref()
                                         .expect("Tried to hit test with no display list")
                                         .hit_test(&point, &rw_data.stacking_context_scroll_offsets);
-                    rw_data.hit_test_response = (result.get(0).cloned(), update_cursor);
+                    rw_data.hit_test_response = (result.last().cloned(), update_cursor);
                 },
                 ReflowQueryType::NodeGeometryQuery(node) => {
                     let node = unsafe { ServoLayoutNode::new(&node) };