add handling for favicon link elements

fixes #6166

components/compositing/compositor.rs

@@ -454,6 +454,10 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                 self.composite_if_necessary(CompositingReason::Headless);
             }
 
+            (Msg::NewFavicon(url), ShutdownState::NotShuttingDown) => {
+                self.window.set_favicon(url);
+            }
+
             // When we are shutting_down, we need to avoid performing operations
             // such as Paint that may crash because we have begun tearing down
             // the rest of our resources.

components/compositing/compositor_task.rs

@@ -180,6 +180,8 @@ pub enum Msg {
     ViewportConstrained(PipelineId, ViewportConstraints),
     /// A reply to the compositor asking if the output image is stable.
     IsReadyToSaveImageReply(bool),
+    /// A favicon was detected
+    NewFavicon(Url),
 }
 
 impl Debug for Msg {
@@ -206,6 +208,7 @@ impl Debug for Msg {
             Msg::PaintTaskExited(..) => write!(f, "PaintTaskExited"),
             Msg::ViewportConstrained(..) => write!(f, "ViewportConstrained"),
             Msg::IsReadyToSaveImageReply(..) => write!(f, "IsReadyToSaveImageReply"),
+            Msg::NewFavicon(..) => write!(f, "NewFavicon"),
         }
     }
 }

components/compositing/constellation.rs

@@ -468,6 +468,10 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
                 debug!("constellation got remove iframe message");
                 self.handle_remove_iframe_msg(containing_pipeline_id, subpage_id);
             }
+            ConstellationMsg::NewFavicon(url) => {
+                debug!("constellation got new favicon message");
+                self.compositor_proxy.send(CompositorMsg::NewFavicon(url));
+            }
         }
         true
     }

components/compositing/headless.rs

@@ -109,6 +109,7 @@ impl CompositorEventListener for NullCompositor {
             Msg::CreatePng(..) |
             Msg::PaintTaskExited(..) |
             Msg::IsReadyToSaveImageReply(..) => {}
+            Msg::NewFavicon(..) => {}
         }
         true
     }

components/compositing/windowing.rs

@@ -138,4 +138,7 @@ pub trait WindowMethods {
 
     /// Does this window support a clipboard
     fn supports_clipboard(&self) -> bool;
+
+    /// Add a favicon
+    fn set_favicon(&self, url: Url);
 }

components/msg/constellation_msg.rs

@@ -248,6 +248,8 @@ pub enum Msg {
     IsReadyToSaveImage(HashMap<PipelineId, Epoch>),
     /// Notification that this iframe should be removed.
     RemoveIFrame(PipelineId, SubpageId),
+    /// Favicon detected
+    NewFavicon(Url),
 }
 
 #[derive(Clone, Eq, PartialEq)]

components/script/dom/htmllinkelement.rs

@@ -25,6 +25,8 @@ use dom::node::{Node, NodeHelpers, NodeTypeId, window_from_node};
 use dom::virtualmethods::VirtualMethods;
 use dom::window::WindowHelpers;
 use layout_interface::{LayoutChan, Msg};
+use msg::constellation_msg::ConstellationChan;
+use msg::constellation_msg::Msg as ConstellationMsg;
 use script_traits::StylesheetLoadResponder;
 use util::str::{DOMString, HTML_SPACE_CHARACTERS};
 use style::media_queries::parse_media_query_list;
@@ -85,6 +87,19 @@ fn is_stylesheet(value: &Option<String>) -> bool {
     }
 }
 
+/// Favicon spec usage in accordance with CEF implementation:
+/// only url of icon is required/used
+/// https://html.spec.whatwg.org/multipage/#rel-icon
+fn is_favicon(value: &Option<String>) -> bool {
+    match *value {
+        Some(ref value) => {
+            value.split(HTML_SPACE_CHARACTERS)
+                .any(|s| s.eq_ignore_ascii_case("icon"))
+        },
+        None => false,
+    }
+}
+
 impl<'a> VirtualMethods for JSRef<'a, HTMLLinkElement> {
     fn super_type<'b>(&'b self) -> Option<&'b VirtualMethods> {
         let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
@@ -105,7 +120,14 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLLinkElement> {
         let rel = get_attr(element, &atom!("rel"));
 
         match (rel, attr.local_name()) {
-            (ref rel, &atom!("href")) | (ref rel, &atom!("media")) => {
+            (ref rel, &atom!("href")) => {
+                if is_stylesheet(rel) {
+                    self.handle_stylesheet_url(&attr.value());
+                } else if is_favicon(rel) {
+                    self.handle_favicon_url(&attr.value());
+                }
+            }
+            (ref rel, &atom!("media")) => {
                 if is_stylesheet(rel) {
                     self.handle_stylesheet_url(&attr.value());
                 }
@@ -136,6 +158,9 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLLinkElement> {
                 (ref rel, Some(ref href)) if is_stylesheet(rel) => {
                     self.handle_stylesheet_url(href);
                 }
+                (ref rel, Some(ref href)) if is_favicon(rel) => {
+                    self.handle_favicon_url(href);
+                }
                 _ => {}
             }
         }
@@ -144,6 +169,7 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLLinkElement> {
 
 trait PrivateHTMLLinkElementHelpers {
     fn handle_stylesheet_url(self, href: &str);
+    fn handle_favicon_url(self, href: &str);
 }
 
 impl<'a> PrivateHTMLLinkElementHelpers for JSRef<'a, HTMLLinkElement> {
@@ -174,6 +200,19 @@ impl<'a> PrivateHTMLLinkElementHelpers for JSRef<'a, HTMLLinkElement> {
             Err(e) => debug!("Parsing url {} failed: {}", href, e)
         }
     }
+
+    fn handle_favicon_url(self, href: &str) {
+        let window = window_from_node(self).root();
+        let window = window.r();
+        match UrlParser::new().base_url(&window.get_url()).parse(href) {
+            Ok(url) => {
+                let ConstellationChan(ref chan) = window.constellation_chan();
+                let event = ConstellationMsg::NewFavicon(url.clone());
+                chan.send(event).unwrap();
+            }
+            Err(e) => debug!("Parsing url {} failed: {}", href, e)
+        }
+    }
 }
 
 impl<'a> HTMLLinkElementMethods for JSRef<'a, HTMLLinkElement> {

ports/cef/window.rs

@@ -316,6 +316,9 @@ impl WindowMethods for Window {
         }
     }
 
+    fn set_favicon(&self, _: Url) {
+    }
+
     fn load_start(&self, back: bool, forward: bool) {
         // FIXME(pcwalton): The status code 200 is a lie.
         let browser = self.cef_browser.borrow();

ports/glutin/window.rs

@@ -559,6 +559,9 @@ impl WindowMethods for Window {
         self.window.set_cursor(glutin_cursor);
     }
 
+    fn set_favicon(&self, _: Url) {
+    }
+
     fn prepare_for_composite(&self, _width: usize, _height: usize) -> bool {
         true
     }
@@ -707,6 +710,9 @@ impl WindowMethods for Window {
     fn set_cursor(&self, _: Cursor) {
     }
 
+    fn set_favicon(&self, _: Url) {
+    }
+
     fn prepare_for_composite(&self, _width: usize, _height: usize) -> bool {
         true
     }

ports/gonk/src/window.rs

@@ -838,6 +838,9 @@ impl WindowMethods for Window {
     fn set_cursor(&self, _: Cursor) {
     }
 
+    fn set_favicon(&self, _: Url) {
+    }
+
     fn prepare_for_composite(&self, _width: usize, _height: usize) -> bool {
         true
     }