Move fragment navigation into Document object

Move the `check_and_scroll_fragment()` method into Document, make the
mothod set the fragment of url after navigation, and use the
`perform_a_scroll()` method to scroll rather than an individual
method. Also removes the broken `Window.fragment` fields.

components/script/dom/document.rs

@@ -18,7 +18,7 @@ use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
 use dom::bindings::codegen::Bindings::NodeFilterBinding::NodeFilter;
 use dom::bindings::codegen::Bindings::PerformanceBinding::PerformanceMethods;
 use dom::bindings::codegen::Bindings::TouchBinding::TouchMethods;
-use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
+use dom::bindings::codegen::Bindings::WindowBinding::{ScrollBehavior, WindowMethods};
 use dom::bindings::codegen::UnionTypes::NodeOrString;
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::{Castable, ElementTypeId, HTMLElementTypeId, NodeTypeId};
@@ -600,6 +600,45 @@ impl Document {
         }
     }
 
+    /// https://html.spec.whatwg.org/multipage/#scroll-to-the-fragment-identifier
+    pub fn check_and_scroll_fragment(&self, fragment: &str) {
+        let target = self.find_fragment_node(fragment);
+
+        // Step 1
+        self.set_target_element(target.r());
+
+        let point = if fragment.is_empty() || fragment.to_lowercase() == "top" {
+            // FIXME(stshine): this should be the origin of the stacking context space,
+            // which may differ under the influence of writing mode.
+            Some((0.0, 0.0))
+        } else {
+            target.r().map(|element| {
+                // FIXME(#8275, pcwalton): This is pretty bogus when multiple layers
+                // are involved. Really what needs to happen is that this needs to go
+                // through layout to ask which layer the element belongs to, and have
+                // it send the scroll message to the compositor.
+                let rect = element.upcast::<Node>().bounding_content_box();
+
+                // In order to align with element edges, we snap to unscaled pixel
+                // boundaries, since the paint thread currently does the same for
+                // drawing elements. This is important for pages that require pixel
+                // perfect scroll positioning for proper display (like Acid2). Since
+                // we don't have the device pixel ratio here, this might not be
+                // accurate, but should work as long as the ratio is a whole number.
+                // Once #8275 is fixed this should actually take into account the
+                // real device pixel ratio.
+                (rect.origin.x.to_nearest_px() as f32,
+                 rect.origin.y.to_nearest_px() as f32)
+            })
+        };
+
+        if let Some((x, y)) = point {
+            // Step 3
+            self.window.perform_a_scroll(x, y, ScrollBehavior::Instant,
+                                         target.r());
+        }
+    }
+
     fn get_anchor_by_name(&self, name: &str) -> Option<Root<Element>> {
         let check_anchor = |node: &HTMLAnchorElement| {
             let elem = node.upcast::<Element>();

components/script/dom/location.rs

@@ -40,7 +40,7 @@ impl Location {
                          setter: fn(&mut ServoUrl, USVString)) {
         let mut url = self.window.get_url();
         setter(&mut url, value);
-        self.window.load_url(url, false, None);
+        self.window.load_url(url, false, false, None);
     }
 }
 
@@ -51,7 +51,7 @@ impl LocationMethods for Location {
         //       _entry settings object_.
         let base_url = self.window.get_url();
         if let Ok(url) = base_url.join(&url.0) {
-            self.window.load_url(url, false, None);
+            self.window.load_url(url, false, false, None);
             Ok(())
         } else {
             Err(Error::Syntax)
@@ -60,7 +60,8 @@ impl LocationMethods for Location {
 
     // https://html.spec.whatwg.org/multipage/#dom-location-reload
     fn Reload(&self) {
-        self.window.load_url(self.get_url(), true, None);
+        self.window.load_url(self.get_url(), true, true, None);
+    }
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-location-hash
@@ -109,7 +110,7 @@ impl LocationMethods for Location {
     // https://html.spec.whatwg.org/multipage/#dom-location-href
     fn SetHref(&self, value: USVString) {
         if let Ok(url) = self.window.get_url().join(&value.0) {
-            self.window.load_url(url, false, None);
+            self.window.load_url(url, false, false, None);
         }
     }
 

components/script/dom/window.rs

@@ -103,6 +103,7 @@ use time;
 use timers::{IsInterval, TimerCallback};
 #[cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))]
 use tinyfiledialogs::{self, MessageBoxIcon};
+use url::Position;
 use util::geometry::{self, max_rect};
 use util::opts;
 use util::prefs::PREFS;
@@ -205,9 +206,6 @@ pub struct Window {
     #[ignore_heap_size_of = "channels are hard"]
     bluetooth_thread: IpcSender<BluetoothRequest>,
 
-    /// Pending scroll to fragment event, if any
-    fragment_name: DOMRefCell<Option<String>>,
-
     /// An enlarged rectangle around the page contents visible in the viewport, used
     /// to prevent creating display list items for content that is far away from the viewport.
     page_clip_rect: Cell<Rect<Au>>,
@@ -1331,13 +1329,24 @@ impl Window {
     }
 
     /// Commence a new URL load which will either replace this window or scroll to a fragment.
-    pub fn load_url(&self, url: ServoUrl, replace: bool, referrer_policy: Option<ReferrerPolicy>) {
+    pub fn load_url(&self, url: ServoUrl, replace: bool, force_reload: bool,
+                    referrer_policy: Option<ReferrerPolicy>) {
         let doc = self.Document();
         let referrer_policy = referrer_policy.or(doc.get_referrer_policy());
 
+        // https://html.spec.whatwg.org/multipage/#navigating-across-documents
+        if !force_reload && url.as_url().unwrap()[..Position::AfterQuery] == doc.url().as_url().unwrap()[..Position::AfterQuery] {
+            // Step 5
+            if let Some(fragment) = url.fragment() {
+                doc.check_and_scroll_fragment(fragment);
+                doc.set_url(url.clone());
+                return
+            }
+        }
+
         self.main_thread_script_chan().send(
             MainThreadScriptMsg::Navigate(self.upcast::<GlobalScope>().pipeline_id(),
-                LoadData::new(url, referrer_policy, Some(doc.url().clone())),
+                LoadData::new(url, referrer_policy, Some(doc.url())),
                 replace)).unwrap();
     }
 
@@ -1348,14 +1357,6 @@ impl Window {
                     ReflowReason::Timer);
     }
 
-    pub fn set_fragment_name(&self, fragment: Option<String>) {
-        *self.fragment_name.borrow_mut() = fragment;
-    }
-
-    pub fn steal_fragment_name(&self) -> Option<String> {
-        self.fragment_name.borrow_mut().take()
-    }
-
     pub fn set_window_size(&self, size: WindowSizeData) {
         self.window_size.set(Some(size));
     }