From a44f79584517c180ba43e1d5d329693bb602aa3f Mon Sep 17 00:00:00 2001
From: Manpreet Singh Matharu <matharumanpreet00@gmail.com>
Date: Fri, 12 Jul 2019 15:52:26 -0400
Subject: [PATCH 1/2] track and update cursor while scrolling

---
 components/compositing/compositor.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/components/compositing/compositor.rs b/components/compositing/compositor.rs
index bb8f4d8f2f0..af71c2dadbc 100644
--- a/components/compositing/compositor.rs
+++ b/components/compositing/compositor.rs
@@ -198,6 +198,9 @@ pub struct IOCompositor<Window: WindowMethods + ?Sized> {
     /// Current mouse cursor.
     cursor: Cursor,
 
+    /// Current cursor position.
+    cursor_pos: DevicePoint,
+
     output_file: Option<String>,
 
     is_running_problem_test: bool,
@@ -320,6 +323,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             webxr_main_thread: state.webxr_main_thread,
             pending_paint_metrics: HashMap::new(),
             cursor: Cursor::None,
+            cursor_pos: DevicePoint::new(0.0, 0.0),
             output_file,
             is_running_problem_test,
             exit_after_load,
@@ -361,6 +365,21 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
         self.webrender.deinit();
     }
 
+    pub fn update_cursor(&mut self) {
+        let results = self.hit_test_at_point(self.cursor_pos);
+        if let Some(item) = results.items.first() {
+            if let Some(cursor) = Cursor::from_u8(item.tag.1 as _) {
+                if cursor != self.cursor {
+                    self.cursor = cursor;
+                    let msg = ConstellationMsg::SetCursor(cursor);
+                    if let Err(e) = self.constellation_chan.send(msg) {
+                        warn!("Sending event to constellation failed ({:?}).", e);
+                    }
+                }
+            }
+        }
+    }
+
     pub fn maybe_start_shutting_down(&mut self) {
         if self.shutdown_state == ShutdownState::NotShuttingDown {
             debug!("Shutting down the constellation for WindowEvent::Quit");
@@ -481,6 +500,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
 
             (Msg::NewScrollFrameReady(recomposite_needed), ShutdownState::NotShuttingDown) => {
                 self.waiting_for_results_of_scroll = false;
+                self.update_cursor();
                 if recomposite_needed {
                     self.composition_request = CompositionRequest::CompositeNow(
                         CompositingReason::NewWebRenderScrollFrame,

From 83ebb85dbd33daf2fbd2d188cd3524ebf3154440 Mon Sep 17 00:00:00 2001
From: Manpreet Singh Matharu <matharumanpreet00@gmail.com>
Date: Sat, 13 Jul 2019 11:33:14 -0400
Subject: [PATCH 2/2] use update_cursor() in
 dispatch_mouse_window_move_event_class() method

---
 components/compositing/compositor.rs | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/components/compositing/compositor.rs b/components/compositing/compositor.rs
index af71c2dadbc..6714834005f 100644
--- a/components/compositing/compositor.rs
+++ b/components/compositing/compositor.rs
@@ -365,9 +365,8 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
         self.webrender.deinit();
     }
 
-    pub fn update_cursor(&mut self) {
-        let results = self.hit_test_at_point(self.cursor_pos);
-        if let Some(item) = results.items.first() {
+    pub fn update_cursor(&mut self, hit_test_results: HitTestResult) {
+        if let Some(item) = hit_test_results.items.first() {
             if let Some(cursor) = Cursor::from_u8(item.tag.1 as _) {
                 if cursor != self.cursor {
                     self.cursor = cursor;
@@ -500,7 +499,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
 
             (Msg::NewScrollFrameReady(recomposite_needed), ShutdownState::NotShuttingDown) => {
                 self.waiting_for_results_of_scroll = false;
-                self.update_cursor();
+                self.update_cursor(self.hit_test_at_point(self.cursor_pos));
                 if recomposite_needed {
                     self.composition_request = CompositionRequest::CompositeNow(
                         CompositingReason::NewWebRenderScrollFrame,
@@ -784,16 +783,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             if let Err(e) = self.constellation_chan.send(msg) {
                 warn!("Sending event to constellation failed ({:?}).", e);
             }
-
-            if let Some(cursor) = Cursor::from_u8(item.tag.1 as _) {
-                if cursor != self.cursor {
-                    self.cursor = cursor;
-                    let msg = ConstellationMsg::SetCursor(cursor);
-                    if let Err(e) = self.constellation_chan.send(msg) {
-                        warn!("Sending event to constellation failed ({:?}).", e);
-                    }
-                }
-            }
+            self.update_cursor(results);
         }
     }