From ab8c00e41a99cbfb72e232879c6100c96c18a40d Mon Sep 17 00:00:00 2001
From: Mats Palmgren <mats@mozilla.com>
Date: Sun, 24 Mar 2019 23:13:53 +0100
Subject: [PATCH] style: Add support for the ::marker pseudo element on list
 items. Alias :-moz-list-bullet/number to that in the parser.

Bug: 205202
Reviewed-by: emilio
---
 components/style/dom.rs                                  | 5 +++++
 components/style/gecko/pseudo_element.rs                 | 4 +++-
 components/style/gecko/pseudo_element_definition.mako.rs | 5 ++++-
 components/style/gecko/wrapper.rs                        | 8 ++++++++
 components/style/invalidation/element/invalidator.rs     | 4 ++++
 5 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/components/style/dom.rs b/components/style/dom.rs
index 1c64543310c..28798e280b6 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -441,6 +441,11 @@ pub trait TElement:
         None
     }
 
+    /// The ::marker pseudo-element of this element, if it exists.
+    fn marker_pseudo_element(&self) -> Option<Self> {
+        None
+    }
+
     /// Execute `f` for each anonymous content child (apart from ::before and
     /// ::after) whose originating element is `self`.
     fn each_anonymous_content_child<F>(&self, _f: F)
diff --git a/components/style/gecko/pseudo_element.rs b/components/style/gecko/pseudo_element.rs
index 8160ea2c9b8..c49277409e0 100644
--- a/components/style/gecko/pseudo_element.rs
+++ b/components/style/gecko/pseudo_element.rs
@@ -33,7 +33,7 @@ impl ::selectors::parser::PseudoElement for PseudoElement {
     fn valid_after_slotted(&self) -> bool {
         matches!(
             *self,
-            PseudoElement::Before | PseudoElement::After | PseudoElement::Placeholder
+            PseudoElement::Before | PseudoElement::After | PseudoElement::Marker | PseudoElement::Placeholder
         )
     }
 
@@ -180,6 +180,8 @@ impl PseudoElement {
     /// Whether this pseudo-element should actually exist if it has
     /// the given styles.
     pub fn should_exist(&self, style: &ComputedValues) -> bool {
+        debug_assert!(self.is_eager());
+
         if style.get_box().clone_display() == Display::None {
             return false;
         }
diff --git a/components/style/gecko/pseudo_element_definition.mako.rs b/components/style/gecko/pseudo_element_definition.mako.rs
index be156b54a14..e2dffcbdd74 100644
--- a/components/style/gecko/pseudo_element_definition.mako.rs
+++ b/components/style/gecko/pseudo_element_definition.mako.rs
@@ -195,13 +195,16 @@ impl PseudoElement {
                 return Some(${pseudo_element_variant(pseudo)})
             }
             % endfor
-            // Alias "-moz-selection" to "selection" at parse time.
+            // Alias some legacy prefixed pseudos to their standardized name at parse time:
             "-moz-selection" => {
                 return Some(PseudoElement::Selection);
             }
             "-moz-placeholder" => {
                 return Some(PseudoElement::Placeholder);
             }
+            "-moz-list-bullet" | "-moz-list-number" => {
+                return Some(PseudoElement::Marker);
+            }
             _ => {
                 if starts_with_ignore_ascii_case(name, "-moz-tree-") {
                     return PseudoElement::tree_pseudo_element(name, Box::new([]))
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 93d3290c191..dedfe7715e8 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1137,6 +1137,14 @@ impl<'le> TElement for GeckoElement<'le> {
         self.before_or_after_pseudo(/* is_before = */ false)
     }
 
+    fn marker_pseudo_element(&self) -> Option<Self> {
+        if !self.has_properties() {
+            return None;
+        }
+
+        unsafe { bindings::Gecko_GetMarkerPseudo(self.0).as_ref().map(GeckoElement) }
+    }
+
     #[inline]
     fn is_html_element(&self) -> bool {
         self.namespace_id() == structs::kNameSpaceID_XHTML as i32
diff --git a/components/style/invalidation/element/invalidator.rs b/components/style/invalidation/element/invalidator.rs
index 4640c7c0442..7ed97c0b197 100644
--- a/components/style/invalidation/element/invalidator.rs
+++ b/components/style/invalidation/element/invalidator.rs
@@ -542,6 +542,10 @@ where
             any_descendant |= self.invalidate_dom_descendants_of(anon_content, invalidations);
         }
 
+        if let Some(marker) = self.element.marker_pseudo_element() {
+            any_descendant |= self.invalidate_pseudo_element_or_nac(marker, invalidations);
+        }
+
         if let Some(before) = self.element.before_pseudo_element() {
             any_descendant |= self.invalidate_pseudo_element_or_nac(before, invalidations);
         }