servo: Merge #17828 - stylo: Visited link fixes (from emilio:visited-now); r=Manishearth

Straight from https://bugzilla.mozilla.org/show_bug.cgi?id=1383307

Source-Repo: https://github.com/servo/servo
Source-Revision: 2241d5879e5d66c52d2b4f17ad730c5de1eff364

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 349558e58d57d1d3ae2dcb1e9a518885384f19a7

servo/components/layout_thread/lib.rs

@@ -594,6 +594,7 @@ impl LayoutThread {
                 stylist: &self.stylist,
                 options: StyleSystemOptions::default(),
                 guards: guards,
+                visited_styles_enabled: false,
                 running_animations: self.running_animations.clone(),
                 expired_animations: self.expired_animations.clone(),
                 local_context_creation_data: Mutex::new(thread_local_style_context_creation_data),

servo/components/style/context.rs

@@ -117,6 +117,9 @@ pub struct SharedStyleContext<'a> {
     /// The CSS selector stylist.
     pub stylist: &'a Stylist,
 
+    /// Whether visited styles are enabled.
+    pub visited_styles_enabled: bool,
+
     /// Configuration options.
     pub options: StyleSystemOptions,
 

servo/components/style/gecko/data.rs

@@ -187,6 +187,13 @@ impl PerDocumentStyleDataImpl {
         );
     }
 
+    /// Returns whether private browsing is enabled.
+    pub fn is_private_browsing_enabled(&self) -> bool {
+        let doc =
+            self.stylist.device().pres_context().mDocument.raw::<nsIDocument>();
+        unsafe { bindings::Gecko_IsPrivateBrowsingEnabled(doc) }
+    }
+
     /// Get the default computed values for this document.
     pub fn default_computed_values(&self) -> &Arc<ComputedValues> {
         self.stylist.device().default_computed_values_arc()

servo/components/style/gecko/generated/bindings.rs

@@ -746,6 +746,12 @@ extern "C" {
                                                        RawGeckoElementBorrowed)
      -> RawServoDeclarationBlockStrongBorrowedOrNull;
 }
+extern "C" {
+    pub fn Gecko_IsPrivateBrowsingEnabled(aDoc: *const nsIDocument) -> bool;
+}
+extern "C" {
+    pub fn Gecko_AreVisitedLinksEnabled() -> bool;
+}
 extern "C" {
     pub fn Gecko_GetAnimationRule(aElementOrPseudo: RawGeckoElementBorrowed,
                                   aCascadeLevel:

servo/components/style/properties/properties.mako.rs

@@ -2837,9 +2837,13 @@ bitflags! {
         /// Whether we're styling the ::-moz-fieldset-content anonymous box.
         const IS_FIELDSET_CONTENT = 1 << 5,
 
+        /// Whether we're computing the style of a link, either visited or
+        /// unvisited.
+        const IS_LINK = 1 << 6,
+
         /// Whether we're computing the style of a link element that happens to
         /// be visited.
-        const IS_VISITED_LINK = 1 << 6,
+        const IS_VISITED_LINK = 1 << 7,
     }
 }
 

servo/components/style/style_adjuster.rs

@@ -436,15 +436,20 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
     /// FIXME(emilio): This isn't technically a style adjustment thingie, could
     /// it move somewhere else?
     fn adjust_for_visited(&mut self, flags: CascadeFlags) {
-        use properties::IS_VISITED_LINK;
+        use properties::{IS_LINK, IS_VISITED_LINK};
         use properties::computed_value_flags::IS_RELEVANT_LINK_VISITED;
 
         if !self.style.has_visited_style() {
             return;
         }
 
-        if flags.contains(IS_VISITED_LINK) ||
-            self.style.inherited_style().flags.contains(IS_RELEVANT_LINK_VISITED) {
+        let relevant_link_visited = if flags.contains(IS_LINK) {
+            flags.contains(IS_VISITED_LINK)
+        } else {
+            self.style.inherited_style().flags.contains(IS_RELEVANT_LINK_VISITED)
+        };
+
+        if relevant_link_visited {
             self.style.flags.insert(IS_RELEVANT_LINK_VISITED);
         }
     }

servo/components/style/style_resolver.rs

@@ -12,7 +12,8 @@ use dom::TElement;
 use log::LogLevel::Trace;
 use matching::{CascadeVisitedMode, MatchMethods};
 use properties::{AnimationRules, CascadeFlags, ComputedValues};
-use properties::{IS_ROOT_ELEMENT, IS_VISITED_LINK, PROHIBIT_DISPLAY_CONTENTS, SKIP_ROOT_AND_ITEM_BASED_DISPLAY_FIXUP};
+use properties::{IS_LINK, IS_ROOT_ELEMENT, IS_VISITED_LINK};
+use properties::{PROHIBIT_DISPLAY_CONTENTS, SKIP_ROOT_AND_ITEM_BASED_DISPLAY_FIXUP};
 use properties::{VISITED_DEPENDENT_ONLY, cascade};
 use rule_tree::StrongRuleNode;
 use selector_parser::{PseudoElement, SelectorImpl};
@@ -474,8 +475,12 @@ where
             cascade_flags.insert(SKIP_ROOT_AND_ITEM_BASED_DISPLAY_FIXUP);
         }
 
-        if pseudo.is_none() && self.element.is_visited_link() {
-            cascade_flags.insert(IS_VISITED_LINK);
+        if pseudo.is_none() && self.element.is_link() {
+            cascade_flags.insert(IS_LINK);
+            if self.element.is_visited_link() &&
+                self.context.shared.visited_styles_enabled {
+                cascade_flags.insert(IS_VISITED_LINK);
+            }
         }
 
         if cascade_visited.visited_dependent_only() {

servo/ports/geckolib/glue.rs

@@ -182,8 +182,13 @@ fn create_shared_context<'a>(global_style_data: &GlobalStyleData,
                              traversal_flags: TraversalFlags,
                              snapshot_map: &'a ServoElementSnapshotTable)
                              -> SharedStyleContext<'a> {
+    let visited_styles_enabled =
+        unsafe { bindings::Gecko_AreVisitedLinksEnabled() } &&
+        !per_doc_data.is_private_browsing_enabled();
+
     SharedStyleContext {
         stylist: &per_doc_data.stylist,
+        visited_styles_enabled: visited_styles_enabled,
         options: global_style_data.options.clone(),
         guards: StylesheetGuards::same(guard),
         timer: Timer::new(),
@@ -1737,8 +1742,7 @@ pub extern "C" fn Servo_ComputedValues_GetStyleBits(values: ServoStyleContextBor
     let flags = values.flags;
     let mut result = 0;
     if flags.contains(IS_RELEVANT_LINK_VISITED) {
-        // FIXME(emilio): This doesn't account for the pref.
-        // result |= structs::NS_STYLE_RELEVANT_LINK_VISITED as u64;
+        result |= structs::NS_STYLE_RELEVANT_LINK_VISITED as u64;
     }
     if flags.contains(HAS_TEXT_DECORATION_LINES) {
         result |= structs::NS_STYLE_HAS_TEXT_DECORATION_LINES as u64;