diff --git a/components/layout/layout_task.rs b/components/layout/layout_task.rs
index 4c982ec9661..010bbdd578f 100644
--- a/components/layout/layout_task.rs
+++ b/components/layout/layout_task.rs
@@ -1276,14 +1276,23 @@ impl LayoutTask {
&self.url,
reflow_info.goal);
- {
- // Perform an abbreviated style recalc that operates without access to the DOM.
- let mut root_flow = (*rw_data.root_flow.as_ref().unwrap()).clone();
- let animations = &*rw_data.running_animations;
- profile(time::ProfilerCategory::LayoutStyleRecalc,
- self.profiler_metadata(),
- self.time_profiler_chan.clone(),
- || animation::recalc_style_for_animations(root_flow.deref_mut(), animations));
+ match rw_data.root_flow.as_ref() {
+ None => {
+ // We haven't performed a single layout yet! Do nothing.
+ return
+ }
+ Some(ref root_flow) => {
+ // Perform an abbreviated style recalc that operates without access to the DOM.
+ let mut root_flow = (*root_flow).clone();
+ let animations = &*rw_data.running_animations;
+ profile(time::ProfilerCategory::LayoutStyleRecalc,
+ self.profiler_metadata(),
+ self.time_profiler_chan.clone(),
+ || {
+ animation::recalc_style_for_animations(root_flow.deref_mut(),
+ animations)
+ });
+ }
}
self.perform_post_style_recalc_layout_passes(&reflow_info,
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 5a1537df1f6..9308a6c527a 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -767,6 +767,12 @@
"url": "/_mozilla/mozilla/window_performance.html"
}
],
+ "mozilla/window_requestAnimationFrame.html": [
+ {
+ "path": "mozilla/window_requestAnimationFrame.html",
+ "url": "/_mozilla/mozilla/window_requestAnimationFrame.html"
+ }
+ ],
"mozilla/window_setInterval.html": [
{
"path": "mozilla/window_setInterval.html",
@@ -1040,4 +1046,4 @@
"rev": null,
"url_base": "/_mozilla/",
"version": 2
-}
\ No newline at end of file
+}
diff --git a/tests/wpt/mozilla/tests/mozilla/window_requestAnimationFrame.html b/tests/wpt/mozilla/tests/mozilla/window_requestAnimationFrame.html
new file mode 100644
index 00000000000..e9c9e5789b0
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/window_requestAnimationFrame.html
@@ -0,0 +1,16 @@
+
+
+ Test throwing an error inside requestAnimationFrame callback
+
+
+
+
+
+
+