Further changes required by Servo

components/style/properties/shorthands/font.mako.rs

@@ -289,7 +289,9 @@
             % for p in subprops_for_value_info:
             ${p}::collect_completion_keywords(f);
             % endfor
+            % if engine == "gecko":
             <SystemFont as SpecifiedValueInfo>::collect_completion_keywords(f);
+            % endif
         }
     }
 </%helpers:shorthand>

components/style/values/specified/font.rs

@@ -70,6 +70,7 @@ macro_rules! system_font_methods {
     Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem
 )]
 #[allow(missing_docs)]
+#[cfg(feature = "gecko")]
 pub enum SystemFont {
     Caption,
     Icon,
@@ -91,6 +92,26 @@ pub enum SystemFont {
     End, // Just for indexing purposes.
 }
 
+// We don't parse system fonts in servo, but in the interest of not
+// littering a lot of code with `if engine == "gecko"` conditionals,
+// we have a dummy system font module that does nothing
+
+#[derive(
+    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem
+)]
+#[allow(missing_docs)]
+#[cfg(feature = "servo")]
+/// void enum for system font, can never exist
+pub enum SystemFont {}
+
+#[allow(missing_docs)]
+#[cfg(feature = "servo")]
+impl SystemFont {
+    pub fn parse(_: &mut Parser) -> Result<Self, ()> {
+        Err(())
+    }
+}
+
 const DEFAULT_SCRIPT_MIN_SIZE_PT: u32 = 8;
 const DEFAULT_SCRIPT_SIZE_MULTIPLIER: f64 = 0.71;