Only element nodes have styles

src/servo/css/matching.rs

@@ -27,10 +27,13 @@ impl Node : MatchMethods {
             kid.restyle_subtree(select_ctx); 
         }
 
-        let select_handler = NodeSelectHandler {
-            node: self
-        };
-        let style = select_ctx.select_style(&self, &select_handler);
-        self.set_css_select_results(move style);
+        // Only elements have styles
+        if self.is_element() {
+            let select_handler = NodeSelectHandler {
+                node: self
+            };
+            let style = select_ctx.select_style(&self, &select_handler);
+            self.set_css_select_results(move style);
+        }
     }
 }

src/servo/css/node_style.rs

@@ -25,6 +25,7 @@ trait StyledNode {
 
 impl Node: StyledNode {
     fn style(&self) -> NodeStyle/&self {
+        assert self.is_element(); // Only elements can have styles
         NodeStyle::new(self)
     }
 }

src/servo/css/select_handler.rs

@@ -6,17 +6,10 @@ pub struct NodeSelectHandler {
     node: Node
 }
 
-/// Placeholder names
-fn unnamed_node(name: &str) -> ~str {
-    fmt!("unnamed-%s", name)
-}
-
 fn node_name(data: &NodeData) -> ~str {
     match *data.kind {
-        Doctype(*) => unnamed_node("doctype"),
-        Comment(*) => unnamed_node("comment"),
         Element(ref data) => copy data.tag_name,
-        Text(*) => unnamed_node("text")
+        _ => fail ~"attempting to style non-element node"
     }
 }
 

src/servo/dom/node.rs

@@ -71,6 +71,12 @@ impl Node : DebugMethods {
     }
 }
 
+impl Node {
+    fn is_element(&self) -> bool {
+        self.read(|n| match *n.kind { Element(*) => true, _ => false } )
+    }
+}
+
 pub enum NodeKind {
     Doctype(DoctypeData),
     Comment(~str),

src/servo/layout/box.rs

@@ -435,6 +435,9 @@ impl RenderBox : RenderBoxMethods {
 
     fn add_bgcolor_to_list(list: &mut DisplayList, abs_bounds: &Rect<Au>) {
         use std::cmp::FuzzyEq;
+
+        if !self.d().node.is_element() { return }
+
         let bgcolor = self.style().background_color();
         if !bgcolor.alpha.fuzzy_eq(&0.0) {
             list.append_item(~DisplayItem::new_SolidColor(abs_bounds, bgcolor.to_gfx_color()));
@@ -442,6 +445,8 @@ impl RenderBox : RenderBoxMethods {
     }
 
     fn add_border_to_list(list: &mut DisplayList, abs_bounds: &Rect<Au>) {
+        if !self.d().node.is_element() { return }
+
         let top_width = self.style().border_top_width();
         let right_width = self.style().border_right_width();
         let bottom_width = self.style().border_bottom_width();