auto merge of #4289 : pcwalton/servo/hacker-news, r=SimonSapin

This patch provides some of the groundwork for column spans greater than
1. It implements the column-span CSS property as well as the
corresponding colspan attribute; although the former is not
well-specified outside of CSS multi-column layout, INTRINSIC refers to
it. Although width is distributed to spanning columns, they do not yet
contribute minimum and preferred widths; this will be implemented in a
follow-up.

The parsing for the legacy bgcolor and border attributes is
implemented according to the WHATWG HTML specification.

Additionally, this patch cleans up some miscellaneous formatting issues,
refactors layout/css somewhat to eliminate needless levels of
indirection, and cleans up the handling of table rowgroups.

New Hacker News screenshot: http://i.imgur.com/hnl2a7E.png

34 files changed, 1429 insertions, 559 deletions

diff --git a/components/layout/Cargo.toml b/components/layout/Cargo.toml
index edd6ed0ad1b..ca77107965b 100644
--- a/components/layout/Cargo.toml
+++ b/components/layout/Cargo.toml
@@ -31,6 +31,9 @@ path = "../net"
 [dependencies.util]
 path = "../util"
 
+[dependencies.cssparser]
+git = "https://github.com/servo/rust-cssparser"
+
 [dependencies.encoding]
 git = "https://github.com/lifthrasiir/rust-encoding"
 
diff --git a/components/layout/css/matching.rs b/components/layout/css/matching.rs
index f1615aa005d..86968a6d9c2 100644
--- a/components/layout/css/matching.rs
+++ b/components/layout/css/matching.rs
@@ -268,6 +268,9 @@ impl StyleSharingCandidate {
             return false
         }
 
+        // FIXME(pcwalton): It's probably faster to iterate over all the element's attributes and
+        // use the {common, rare}-style-affecting-attributes tables as lookup tables.
+
         for attribute_info in style::common_style_affecting_attributes().iter() {
             match attribute_info.mode {
                 AttrIsPresentMode(flag) => {
@@ -295,6 +298,12 @@ impl StyleSharingCandidate {
             }
         }
 
+        for attribute_name in style::rare_style_affecting_attributes().iter() {
+            if element.get_attr(&ns!(""), attribute_name).is_some() {
+                return false
+            }
+        }
+
         if element.get_link().is_some() != self.link {
             return false
         }
diff --git a/components/layout/css/node_style.rs b/components/layout/css/node_style.rs
index ecfb3383453..c3eaa04ddd2 100644
--- a/components/layout/css/node_style.rs
+++ b/components/layout/css/node_style.rs
@@ -2,27 +2,75 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// Style retrieval from DOM elements.
+//! Style retrieval from DOM elements.
 
-use css::node_util::NodeUtil;
-use wrapper::ThreadSafeLayoutNode;
+use wrapper::{After, Before, Normal, ThreadSafeLayoutNode};
 
+use std::mem;
 use style::ComputedValues;
 use sync::Arc;
 
 /// Node mixin providing `style` method that returns a `NodeStyle`
 pub trait StyledNode {
+    /// Returns the style results for the given node. If CSS selector matching has not yet been
+    /// performed, fails.
     fn style<'a>(&'a self) -> &'a Arc<ComputedValues>;
+    /// Does this node have a computed style yet?
+    fn has_style(&self) -> bool;
+    /// Removes the style from this node.
     fn unstyle(self);
 }
 
 impl<'ln> StyledNode for ThreadSafeLayoutNode<'ln> {
     #[inline]
     fn style<'a>(&'a self) -> &'a Arc<ComputedValues> {
-        self.get_css_select_results()
+        unsafe {
+            let layout_data_ref = self.borrow_layout_data();
+            match self.get_pseudo_element_type() {
+                Before(_) => {
+                     mem::transmute(layout_data_ref.as_ref()
+                                                   .unwrap()
+                                                   .data
+                                                   .before_style
+                                                   .as_ref()
+                                                   .unwrap())
+                }
+                After(_) => {
+                    mem::transmute(layout_data_ref.as_ref()
+                                                  .unwrap()
+                                                  .data
+                                                  .after_style
+                                                  .as_ref()
+                                                  .unwrap())
+                }
+                Normal => {
+                    mem::transmute(layout_data_ref.as_ref()
+                                                  .unwrap()
+                                                  .shared_data
+                                                  .style
+                                                  .as_ref()
+                                                  .unwrap())
+                }
+            }
+        }
+    }
+
+    fn has_style(&self) -> bool {
+        let layout_data_ref = self.borrow_layout_data();
+        layout_data_ref.as_ref().unwrap().shared_data.style.is_some()
     }
 
     fn unstyle(self) {
-        self.remove_css_select_results()
+        let mut layout_data_ref = self.mutate_layout_data();
+        let layout_data = layout_data_ref.as_mut().expect("no layout data");
+
+        let style =
+            match self.get_pseudo_element_type() {
+                Before(_) => &mut layout_data.data.before_style,
+                After (_) => &mut layout_data.data.after_style,
+                Normal    => &mut layout_data.shared_data.style,
+            };
+
+        *style = None;
     }
 }
diff --git a/components/layout/css/node_util.rs b/components/layout/css/node_util.rs
deleted file mode 100644
index eb447b0cf6b..00000000000
--- a/components/layout/css/node_util.rs
+++ /dev/null
@@ -1,75 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-use util::LayoutDataAccess;
-use wrapper::ThreadSafeLayoutNode;
-use wrapper::{After, Before, Normal};
-
-use std::mem;
-use style::ComputedValues;
-use sync::Arc;
-
-pub trait NodeUtil {
-    fn get_css_select_results<'a>(&'a self) -> &'a Arc<ComputedValues>;
-    fn have_css_select_results(&self) -> bool;
-    fn remove_css_select_results(self);
-}
-
-impl<'ln> NodeUtil for ThreadSafeLayoutNode<'ln> {
-    /// Returns the style results for the given node. If CSS selector
-    /// matching has not yet been performed, fails.
-    #[inline]
-    fn get_css_select_results<'a>(&'a self) -> &'a Arc<ComputedValues> {
-        unsafe {
-            let layout_data_ref = self.borrow_layout_data();
-            match self.get_pseudo_element_type() {
-                Before(_) => {
-                     mem::transmute(layout_data_ref.as_ref()
-                                                   .unwrap()
-                                                   .data
-                                                   .before_style
-                                                   .as_ref()
-                                                   .unwrap())
-                }
-                After(_) => {
-                    mem::transmute(layout_data_ref.as_ref()
-                                                  .unwrap()
-                                                  .data
-                                                  .after_style
-                                                  .as_ref()
-                                                  .unwrap())
-                }
-                Normal => {
-                    mem::transmute(layout_data_ref.as_ref()
-                                                  .unwrap()
-                                                  .shared_data
-                                                  .style
-                                                  .as_ref()
-                                                  .unwrap())
-                }
-            }
-        }
-    }
-
-    /// Does this node have a computed style yet?
-    fn have_css_select_results(&self) -> bool {
-        let layout_data_ref = self.borrow_layout_data();
-        layout_data_ref.as_ref().unwrap().shared_data.style.is_some()
-    }
-
-    fn remove_css_select_results(self) {
-        let mut layout_data_ref = self.mutate_layout_data();
-        let layout_data = layout_data_ref.as_mut().expect("no layout data");
-
-        let style =
-            match self.get_pseudo_element_type() {
-                Before(_) => &mut layout_data.data.before_style,
-                After (_) => &mut layout_data.data.after_style,
-                Normal    => &mut layout_data.shared_data.style,
-            };
-
-        *style = None;
-    }
-}
-
diff --git a/components/layout/layout_task.rs b/components/layout/layout_task.rs
index deda7d481c7..d187aa1a37f 100644
--- a/components/layout/layout_task.rs
+++ b/components/layout/layout_task.rs
@@ -40,7 +40,7 @@ use script::layout_interface::{ContentBoxesQuery, ContentBoxQuery, ExitNowMsg, G
 use script::layout_interface::{HitTestResponse, LayoutChan, LayoutRPC, LoadStylesheetMsg};
 use script::layout_interface::{MouseOverResponse, Msg, NoQuery, PrepareToExitMsg};
 use script::layout_interface::{ReapLayoutDataMsg, Reflow, ReflowForDisplay, ReflowMsg};
-use script::layout_interface::{ScriptLayoutChan, TrustedNodeAddress};
+use script::layout_interface::{ScriptLayoutChan, SetQuirksModeMsg, TrustedNodeAddress};
 use script_traits::{SendEventMsg, ReflowEvent, ReflowCompleteMsg, OpaqueScriptLayoutChannel};
 use script_traits::{ScriptControlChan, UntrustedNodeAddress};
 use servo_msg::compositor_msg::Scrollable;
@@ -390,6 +390,7 @@ impl LayoutTask {
         match request {
             AddStylesheetMsg(sheet) => self.handle_add_stylesheet(sheet, possibly_locked_rw_data),
             LoadStylesheetMsg(url) => self.handle_load_stylesheet(url, possibly_locked_rw_data),
+            SetQuirksModeMsg => self.handle_set_quirks_mode(possibly_locked_rw_data),
             GetRPCMsg(response_chan) => {
                 response_chan.send(box LayoutRPCImpl(self.rw_data.clone()) as
                                    Box<LayoutRPC + Send>);
@@ -500,6 +501,15 @@ impl LayoutTask {
         LayoutTask::return_rw_data(possibly_locked_rw_data, rw_data);
     }
 
+    /// Sets quirks mode for the document, causing the quirks mode stylesheet to be loaded.
+    fn handle_set_quirks_mode<'a>(&'a self,
+                                  possibly_locked_rw_data:
+                                    &mut Option<MutexGuard<'a, LayoutTaskData>>) {
+        let mut rw_data = self.lock_rw_data(possibly_locked_rw_data);
+        rw_data.stylist.add_quirks_mode_stylesheet();
+        LayoutTask::return_rw_data(possibly_locked_rw_data, rw_data);
+    }
+
     /// Retrieves the flow tree root from the root node.
     fn try_get_layout_root(&self, node: LayoutNode) -> Option<FlowRef> {
         let mut layout_data_ref = node.mutate_layout_data();
diff --git a/components/layout/lib.rs b/components/layout/lib.rs
index 1fa21311373..26054f0dae0 100644
--- a/components/layout/lib.rs
+++ b/components/layout/lib.rs
@@ -14,6 +14,7 @@
 #[phase(plugin, link)]
 extern crate log;
 
+extern crate cssparser;
 extern crate geom;
 extern crate gfx;
 extern crate layout_traits;
@@ -70,8 +71,6 @@ pub mod incremental;
 pub mod wrapper;
 
 pub mod css {
-    mod node_util;
-
     pub mod matching;
     pub mod node_style;
 }
diff --git a/components/layout/table.rs b/components/layout/table.rs
index 37f589917a2..0e2af0b2f68 100644
--- a/components/layout/table.rs
+++ b/components/layout/table.rs
@@ -11,11 +11,12 @@ use block::{ISizeConstraintInput, ISizeConstraintSolution};
 use construct::FlowConstructor;
 use context::LayoutContext;
 use floats::FloatKind;
-use flow::{Flow, FlowClass, IMPACTED_BY_LEFT_FLOATS, IMPACTED_BY_RIGHT_FLOATS, ImmutableFlowUtils};
-use flow::{TableFlowClass};
+use flow::{mod, Flow, FlowClass, IMPACTED_BY_LEFT_FLOATS, IMPACTED_BY_RIGHT_FLOATS};
+use flow::{ImmutableFlowUtils, TableFlowClass};
 use fragment::{Fragment, FragmentBoundsIterator};
 use layout_debug;
 use model::{IntrinsicISizes, IntrinsicISizesContribution};
+use table_row::CellIntrinsicInlineSize;
 use table_wrapper::{TableLayout, FixedLayout, AutoLayout};
 use wrapper::ThreadSafeLayoutNode;
 
@@ -105,24 +106,53 @@ impl TableFlow {
     /// Update the corresponding value of `self_inline_sizes` if a value of `kid_inline_sizes` has
     /// a larger value than one of `self_inline_sizes`. Returns the minimum and preferred inline
     /// sizes.
-    pub fn update_column_inline_sizes(parent_inline_sizes: &mut Vec<ColumnIntrinsicInlineSize>,
-                                      child_inline_sizes: &Vec<ColumnIntrinsicInlineSize>)
-                                      -> IntrinsicISizes {
+    fn update_automatic_column_inline_sizes(
+            parent_inline_sizes: &mut Vec<ColumnIntrinsicInlineSize>,
+            child_cell_inline_sizes: &[CellIntrinsicInlineSize])
+            -> IntrinsicISizes {
         let mut total_inline_sizes = IntrinsicISizes::new();
-        for (parent_sizes, child_sizes) in parent_inline_sizes.iter_mut()
-                                                              .zip(child_inline_sizes.iter()) {
-            *parent_sizes = ColumnIntrinsicInlineSize {
-                minimum_length: max(parent_sizes.minimum_length, child_sizes.minimum_length),
-                percentage: parent_sizes.greatest_percentage(child_sizes),
-                preferred: max(parent_sizes.preferred, child_sizes.preferred),
-                constrained: parent_sizes.constrained || child_sizes.constrained
-            };
-
-            total_inline_sizes.minimum_inline_size = total_inline_sizes.minimum_inline_size +
-                parent_sizes.minimum_length;
-            total_inline_sizes.preferred_inline_size = total_inline_sizes.preferred_inline_size +
-                parent_sizes.preferred;
+        let mut column_index = 0;
+        for child_cell_inline_size in child_cell_inline_sizes.iter() {
+            for _ in range(0, child_cell_inline_size.column_span) {
+                if column_index < parent_inline_sizes.len() {
+                    // We already have some intrinsic size information for this column. Merge it in
+                    // according to the rules specified in INTRINSIC § 4.
+                    let parent_sizes = &mut parent_inline_sizes[column_index];
+                    if child_cell_inline_size.column_span > 1 {
+                        // TODO(pcwalton): Perform the recursive algorithm specified in INTRINSIC §
+                        // 4. For now we make this column contribute no width.
+                    } else {
+                        let column_size = &child_cell_inline_size.column_size;
+                        *parent_sizes = ColumnIntrinsicInlineSize {
+                            minimum_length: max(parent_sizes.minimum_length,
+                                                column_size.minimum_length),
+                            percentage: parent_sizes.greatest_percentage(column_size),
+                            preferred: max(parent_sizes.preferred, column_size.preferred),
+                            constrained: parent_sizes.constrained || column_size.constrained,
+                        }
+                    }
+                } else {
+                    // We discovered a new column. Initialize its data.
+                    debug_assert!(column_index == parent_inline_sizes.len());
+                    if child_cell_inline_size.column_span > 1 {
+                        // TODO(pcwalton): Perform the recursive algorithm specified in INTRINSIC §
+                        // 4. For now we make this column contribute no width.
+                        parent_inline_sizes.push(ColumnIntrinsicInlineSize::new())
+                    } else {
+                        parent_inline_sizes.push(child_cell_inline_size.column_size)
+                    }
+                }
+
+                total_inline_sizes.minimum_inline_size = total_inline_sizes.minimum_inline_size +
+                    parent_inline_sizes[column_index].minimum_length;
+                total_inline_sizes.preferred_inline_size =
+                    total_inline_sizes.preferred_inline_size +
+                    parent_inline_sizes[column_index].preferred;
+
+                column_index += 1
+            }
         }
+
         total_inline_sizes
     }
 
@@ -136,6 +166,39 @@ impl TableFlow {
     fn assign_block_size_table_base<'a>(&mut self, layout_context: &'a LayoutContext<'a>) {
         self.block_flow.assign_block_size_block_base(layout_context, MarginsMayNotCollapse);
     }
+
+    /// Updates the minimum and preferred inline-size calculation for a single row. This is
+    /// factored out into a separate function because we process children of rowgroups too.
+    fn update_column_inline_sizes_for_row(child: &mut Flow,
+                                          column_inline_sizes: &mut Vec<ColumnIntrinsicInlineSize>,
+                                          computation: &mut IntrinsicISizesContribution,
+                                          did_first_row: &mut bool,
+                                          table_layout: TableLayout) {
+        // Read column inline-sizes from the table-row, and assign inline-size=0 for the columns
+        // not defined in the column group.
+        //
+        // FIXME: Need to read inline-sizes from either table-header-group OR the first table-row.
+        debug_assert!(child.is_table_row());
+        let row = child.as_table_row();
+        match table_layout {
+            FixedLayout => {
+                // Fixed table layout only looks at the first row.
+                //
+                // FIXME(pcwalton): This is really inefficient. We should stop after the first row!
+                if !*did_first_row {
+                    *did_first_row = true;
+                    for cell_inline_size in row.cell_intrinsic_inline_sizes.iter() {
+                        column_inline_sizes.push(cell_inline_size.column_size);
+                    }
+                }
+            }
+            AutoLayout => {
+                computation.union_block(&TableFlow::update_automatic_column_inline_sizes(
+                    column_inline_sizes,
+                    row.cell_intrinsic_inline_sizes.as_slice()))
+            }
+        }
+    }
 }
 
 impl Flow for TableFlow {
@@ -190,50 +253,22 @@ impl Flow for TableFlow {
                         constrained: false,
                     })
                 }
-            } else if kid.is_table_rowgroup() || kid.is_table_row() {
-                // Read column inline-sizes from the table-row-group/table-row, and assign
-                // inline-size=0 for the columns not defined in the column group.
-                // FIXME: Need to read inline-sizes from either table-header-group OR the first
-                // table-row.
-                match self.table_layout {
-                    FixedLayout => {
-                        // Fixed table layout only looks at the first row.
-                        if !did_first_row {
-                            did_first_row = true;
-                            for child_column_inline_size in kid.column_intrinsic_inline_sizes()
-                                                               .iter() {
-                                self.column_intrinsic_inline_sizes.push(*child_column_inline_size);
-                            }
-                        }
-                    }
-                    AutoLayout => {
-                        let child_column_inline_sizes = kid.column_intrinsic_inline_sizes();
-                        let mut child_intrinsic_sizes = TableFlow::update_column_inline_sizes(
-                            &mut self.column_intrinsic_inline_sizes,
-                            child_column_inline_sizes);
-
-                        // Add new columns if processing this row caused us to discover them.
-                        let child_column_count = child_column_inline_sizes.len();
-                        let parent_column_count = self.column_intrinsic_inline_sizes.len();
-                        debug!("table until the previous row has {} column(s) and this row has {} \
-                                column(s)",
-                               parent_column_count,
-                               child_column_count);
-                        self.column_intrinsic_inline_sizes.reserve(child_column_count);
-                        for i in range(parent_column_count, child_column_count) {
-                            let inline_size_for_new_column = (*child_column_inline_sizes)[i];
-                            child_intrinsic_sizes.minimum_inline_size =
-                                child_intrinsic_sizes.minimum_inline_size +
-                                inline_size_for_new_column.minimum_length;
-                            child_intrinsic_sizes.preferred_inline_size =
-                                child_intrinsic_sizes.preferred_inline_size +
-                                inline_size_for_new_column.preferred;
-                            self.column_intrinsic_inline_sizes.push(inline_size_for_new_column);
-                        }
-
-                        computation.union_block(&child_intrinsic_sizes)
-                    }
+            } else if kid.is_table_rowgroup() {
+                for grandkid in flow::mut_base(kid).child_iter() {
+                    TableFlow::update_column_inline_sizes_for_row(
+                        grandkid,
+                        &mut self.column_intrinsic_inline_sizes,
+                        &mut computation,
+                        &mut did_first_row,
+                        self.table_layout)
                 }
+            } else if kid.is_table_row() {
+                TableFlow::update_column_inline_sizes_for_row(
+                        kid,
+                        &mut self.column_intrinsic_inline_sizes,
+                        &mut computation,
+                        &mut did_first_row,
+                        self.table_layout)
             }
         }
 
@@ -277,8 +312,7 @@ impl Flow for TableFlow {
                 // In fixed table layout, we distribute extra space among the unspecified columns
                 // if there are any, or among all the columns if all are specified.
                 self.column_computed_inline_sizes.clear();
-                if total_column_inline_size < content_inline_size &&
-                        num_unspecified_inline_sizes == 0 {
+                if num_unspecified_inline_sizes == 0 {
                     let ratio = content_inline_size.to_subpx() /
                         total_column_inline_size.to_subpx();
                     for column_inline_size in self.column_intrinsic_inline_sizes.iter() {
@@ -413,6 +447,16 @@ pub struct ColumnIntrinsicInlineSize {
 }
 
 impl ColumnIntrinsicInlineSize {
+    /// Returns a newly-initialized `ColumnIntrinsicInlineSize` with all fields blank.
+    pub fn new() -> ColumnIntrinsicInlineSize {
+        ColumnIntrinsicInlineSize {
+            preferred: Au(0),
+            minimum_length: Au(0),
+            percentage: 0.0,
+            constrained: false,
+        }
+    }
+
     /// Returns the true minimum size of this column, given the containing block's inline size.
     /// Beware that this is generally only correct for fixed table layout. (Compare CSS 2.1 §
     /// 17.5.2.1 with the algorithm in INTRINSIC § 4.)
diff --git a/components/layout/table_cell.rs b/components/layout/table_cell.rs
index 280e86408cb..0a4e7d05e24 100644
--- a/components/layout/table_cell.rs
+++ b/components/layout/table_cell.rs
@@ -17,7 +17,7 @@ use wrapper::ThreadSafeLayoutNode;
 
 use servo_util::geometry::Au;
 use std::fmt;
-use style::ComputedValues;
+use style::{ColSpanUnsignedIntegerAttribute, ComputedValues};
 use sync::Arc;
 
 /// A table formatting context.
@@ -25,13 +25,17 @@ use sync::Arc;
 pub struct TableCellFlow {
     /// Data common to all block flows.
     pub block_flow: BlockFlow,
+    /// The column span of this cell.
+    pub column_span: u32,
 }
 
 impl TableCellFlow {
     pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode, fragment: Fragment)
                                   -> TableCellFlow {
         TableCellFlow {
-            block_flow: BlockFlow::from_node_and_fragment(node, fragment)
+            block_flow: BlockFlow::from_node_and_fragment(node, fragment),
+            column_span: node.get_unsigned_integer_attribute(ColSpanUnsignedIntegerAttribute)
+                             .unwrap_or(1),
         }
     }
 
diff --git a/components/layout/table_row.rs b/components/layout/table_row.rs
index 307892635a0..e50f5b2f33e 100644
--- a/components/layout/table_row.rs
+++ b/components/layout/table_row.rs
@@ -30,20 +30,29 @@ use sync::Arc;
 pub struct TableRowFlow {
     pub block_flow: BlockFlow,
 
-    /// Information about the intrinsic inline-sizes of each column.
-    pub column_intrinsic_inline_sizes: Vec<ColumnIntrinsicInlineSize>,
+    /// Information about the intrinsic inline-sizes of each cell.
+    pub cell_intrinsic_inline_sizes: Vec<CellIntrinsicInlineSize>,
 
     /// Information about the computed inline-sizes of each column.
     pub column_computed_inline_sizes: Vec<ColumnComputedInlineSize>,
 }
 
+/// Information about the column inline size and span for each cell.
+#[deriving(Encodable)]
+pub struct CellIntrinsicInlineSize {
+    /// Inline sizes that this cell contributes to the column.
+    pub column_size: ColumnIntrinsicInlineSize,
+    /// The column span of this cell.
+    pub column_span: u32,
+}
+
 impl TableRowFlow {
     pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode,
                                   fragment: Fragment)
                                   -> TableRowFlow {
         TableRowFlow {
             block_flow: BlockFlow::from_node_and_fragment(node, fragment),
-            column_intrinsic_inline_sizes: Vec::new(),
+            cell_intrinsic_inline_sizes: Vec::new(),
             column_computed_inline_sizes: Vec::new(),
         }
     }
@@ -53,8 +62,8 @@ impl TableRowFlow {
                      -> TableRowFlow {
         TableRowFlow {
             block_flow: BlockFlow::from_node(constructor, node),
-            column_intrinsic_inline_sizes: Vec::new(),
-            column_computed_inline_sizes: Vec::new(),
+            cell_intrinsic_inline_sizes: Vec::new(),
+            column_computed_inline_sizes: Vec::new()
         }
     }
 
@@ -156,7 +165,7 @@ impl Flow for TableRowFlow {
     }
 
     fn column_intrinsic_inline_sizes<'a>(&'a mut self) -> &'a mut Vec<ColumnIntrinsicInlineSize> {
-        &mut self.column_intrinsic_inline_sizes
+        panic!("can't call column_intrinsic_inline_sizes() on table row")
     }
 
     fn column_computed_inline_sizes<'a>(&'a mut self) -> &'a mut Vec<ColumnComputedInlineSize> {
@@ -181,10 +190,15 @@ impl Flow for TableRowFlow {
 
             // Collect the specified column inline-size of the cell. This is used in both fixed and
             // automatic table layout calculation.
-            let child_specified_inline_size = kid.as_table_cell()
-                                                 .fragment()
-                                                 .style()
-                                                 .content_inline_size();
+            let child_specified_inline_size;
+            let child_column_span;
+            {
+                let child_table_cell = kid.as_table_cell();
+                child_specified_inline_size = child_table_cell.fragment()
+                                                              .style()
+                                                              .content_inline_size();
+                child_column_span = child_table_cell.column_span
+            }
 
             // Collect minimum and preferred inline-sizes of the cell for automatic table layout
             // calculation.
@@ -208,15 +222,16 @@ impl Flow for TableRowFlow {
             };
             min_inline_size = min_inline_size + child_column_inline_size.minimum_length;
             pref_inline_size = pref_inline_size + child_column_inline_size.preferred;
-            self.column_intrinsic_inline_sizes.push(child_column_inline_size);
+            self.cell_intrinsic_inline_sizes.push(CellIntrinsicInlineSize {
+                column_size: child_column_inline_size,
+                column_span: child_column_span,
+            });
         }
         self.block_flow.base.intrinsic_inline_sizes.minimum_inline_size = min_inline_size;
         self.block_flow.base.intrinsic_inline_sizes.preferred_inline_size = max(min_inline_size,
                                                                                 pref_inline_size);
     }
 
-    /// Recursively (top-down) determines the actual inline-size of child contexts and fragments.
-    /// When called on this context, the context has had its inline-size set by the parent context.
     fn assign_inline_sizes(&mut self, layout_context: &LayoutContext) {
         let _scope = layout_debug_scope!("table_row::assign_inline_sizes {:x}",
                                          self.block_flow.base.debug_id());
@@ -233,11 +248,46 @@ impl Flow for TableRowFlow {
                                                       layout_context,
                                                       containing_block_inline_size);
 
+        // Spread out the completed inline sizes among columns with spans > 1.
+        let mut computed_inline_size_for_cells = Vec::new();
+        let mut column_computed_inline_size_iterator = self.column_computed_inline_sizes.iter();
+        for cell_intrinsic_inline_size in self.cell_intrinsic_inline_sizes.iter() {
+            // Start with the computed inline size for the first column in the span.
+            let mut column_computed_inline_size =
+                match column_computed_inline_size_iterator.next() {
+                    Some(column_computed_inline_size) => *column_computed_inline_size,
+                    None => {
+                        // We're in fixed layout mode and there are more cells in this row than
+                        // columns we know about. According to CSS 2.1 § 17.5.2.1, the behavior is
+                        // now undefined. So just use zero.
+                        //
+                        // FIXME(pcwalton): $10 says this isn't Web compatible.
+                        ColumnComputedInlineSize {
+                            size: Au(0),
+                        }
+                    }
+                };
+
+            // Add in computed inline sizes for any extra columns in the span.
+            for _ in range(1, cell_intrinsic_inline_size.column_span) {
+                let extra_column_computed_inline_size =
+                    match column_computed_inline_size_iterator.next() {
+                        Some(column_computed_inline_size) => column_computed_inline_size,
+                        None => break,
+                    };
+                column_computed_inline_size.size = column_computed_inline_size.size +
+                    extra_column_computed_inline_size.size;
+            }
+
+            computed_inline_size_for_cells.push(column_computed_inline_size)
+        }
+
+        // Push those inline sizes down to the cells.
         self.block_flow.propagate_assigned_inline_size_to_children(
             layout_context,
             inline_start_content_edge,
             containing_block_inline_size,
-            Some(self.column_computed_inline_sizes.as_slice()));
+            Some(computed_inline_size_for_cells.as_slice()));
     }
 
     fn assign_block_size<'a>(&mut self, ctx: &'a LayoutContext<'a>) {
diff --git a/components/layout/table_rowgroup.rs b/components/layout/table_rowgroup.rs
index c3837185a47..4f62cd10a75 100644
--- a/components/layout/table_rowgroup.rs
+++ b/components/layout/table_rowgroup.rs
@@ -9,11 +9,10 @@
 use block::{BlockFlow, ISizeAndMarginsComputer, MarginsMayNotCollapse};
 use construct::FlowConstructor;
 use context::LayoutContext;
-use flow::{TableRowGroupFlowClass, FlowClass, Flow, ImmutableFlowUtils};
+use flow::{Flow, FlowClass, TableRowGroupFlowClass};
 use fragment::{Fragment, FragmentBoundsIterator};
 use layout_debug;
-use model::IntrinsicISizesContribution;
-use table::{ColumnComputedInlineSize, ColumnIntrinsicInlineSize, InternalTable, TableFlow};
+use table::{ColumnComputedInlineSize, ColumnIntrinsicInlineSize, InternalTable};
 use wrapper::ThreadSafeLayoutNode;
 
 use servo_util::geometry::Au;
@@ -24,6 +23,7 @@ use sync::Arc;
 /// A table formatting context.
 #[deriving(Encodable)]
 pub struct TableRowGroupFlow {
+    /// Fields common to all block flows.
     pub block_flow: BlockFlow,
 
     /// Information about the intrinsic inline-sizes of each column.
@@ -91,54 +91,11 @@ impl Flow for TableRowGroupFlow {
         &mut self.column_computed_inline_sizes
     }
 
-
-    /// Recursively (bottom-up) determines the context's preferred and minimum inline-sizes. When
-    /// called on this context, all child contexts have had their min/pref inline-sizes set. This
-    /// function must decide min/pref inline-sizes based on child context inline-sizes and
-    /// dimensions of any fragments it is responsible for flowing.
-    ///
-    /// Min/pref inline-sizes set by this function are used in automatic table layout calculation.
-    ///
-    /// Also, this function finds the specified column inline-sizes from the first row. These are
-    /// used in fixed table layout calculation.
     fn bubble_inline_sizes(&mut self) {
         let _scope = layout_debug_scope!("table_rowgroup::bubble_inline_sizes {:x}",
                                          self.block_flow.base.debug_id());
-
-        let mut computation = IntrinsicISizesContribution::new();
-        for kid in self.block_flow.base.child_iter() {
-            assert!(kid.is_table_row());
-
-            // Calculate minimum and preferred inline sizes for automatic table layout.
-            if self.column_intrinsic_inline_sizes.is_empty() {
-                // We're the first row.
-                self.column_intrinsic_inline_sizes = kid.column_intrinsic_inline_sizes().clone();
-            } else {
-                let mut child_intrinsic_sizes =
-                    TableFlow::update_column_inline_sizes(&mut self.column_intrinsic_inline_sizes,
-                                                          kid.column_intrinsic_inline_sizes());
-
-                // update the number of column inline-sizes from table-rows.
-                let column_count = self.column_intrinsic_inline_sizes.len();
-                let child_column_count = kid.column_intrinsic_inline_sizes().len();
-                for i in range(column_count, child_column_count) {
-                    let this_column_inline_size = (*kid.column_intrinsic_inline_sizes())[i];
-
-                    // FIXME(pcwalton): Ignoring the percentage here seems dubious.
-                    child_intrinsic_sizes.minimum_inline_size =
-                        child_intrinsic_sizes.minimum_inline_size +
-                        this_column_inline_size.minimum_length;
-                    child_intrinsic_sizes.preferred_inline_size =
-                        child_intrinsic_sizes.preferred_inline_size +
-                        this_column_inline_size.preferred;
-                    self.column_intrinsic_inline_sizes.push(this_column_inline_size);
-                }
-
-                computation.union_block(&child_intrinsic_sizes)
-            }
-        }
-
-        self.block_flow.base.intrinsic_inline_sizes = computation.finish()
+        // Proper calculation of intrinsic sizes in table layout requires access to the entire
+        // table, which we don't have yet. Defer to our parent.
     }
 
     /// Recursively (top-down) determines the actual inline-size of child contexts and fragments.
diff --git a/components/layout/table_wrapper.rs b/components/layout/table_wrapper.rs
index 271a6545d1d..0d785ce1ca3 100644
--- a/components/layout/table_wrapper.rs
+++ b/components/layout/table_wrapper.rs
@@ -31,7 +31,7 @@ use style::{ComputedValues, CSSFloat};
 use style::computed_values::table_layout;
 use sync::Arc;
 
-#[deriving(Encodable)]
+#[deriving(Encodable, Show)]
 pub enum TableLayout {
     FixedLayout,
     AutoLayout
diff --git a/components/layout/wrapper.rs b/components/layout/wrapper.rs
index 9a70539c78b..97aa8dd189a 100644
--- a/components/layout/wrapper.rs
+++ b/components/layout/wrapper.rs
@@ -36,6 +36,7 @@ use incremental::RestyleDamage;
 use util::{LayoutDataAccess, LayoutDataFlags, LayoutDataWrapper, OpaqueNodeMethods};
 use util::{PrivateLayoutData};
 
+use cssparser::RGBA;
 use gfx::display_list::OpaqueNode;
 use script::dom::bindings::codegen::InheritTypes::{ElementCast, HTMLIFrameElementCast};
 use script::dom::bindings::codegen::InheritTypes::{HTMLImageElementCast, HTMLInputElementCast};
@@ -56,11 +57,12 @@ use servo_msg::constellation_msg::{PipelineId, SubpageId};
 use servo_util::str::{LengthOrPercentageOrAuto, is_whitespace};
 use std::kinds::marker::ContravariantLifetime;
 use std::mem;
+use string_cache::{Atom, Namespace};
 use style::computed_values::{content, display, white_space};
-use style::{AnyNamespace, AttrSelector, IntegerAttribute, LengthAttribute};
-use style::{PropertyDeclarationBlock, SpecificNamespace, TElement, TElementAttributes, TNode};
+use style::{AnyNamespace, AttrSelector, BorderUnsignedIntegerAttribute, IntegerAttribute};
+use style::{LengthAttribute, PropertyDeclarationBlock, SimpleColorAttribute, SpecificNamespace};
+use style::{TElement, TElementAttributes, TNode, UnsignedIntegerAttribute};
 use url::Url;
-use string_cache::{Atom, Namespace};
 
 use std::cell::{Ref, RefMut};
 
@@ -580,6 +582,17 @@ impl<'le> TElement<'le> for LayoutElement<'le> {
             }
         }
     }
+
+    #[inline]
+    fn has_nonzero_border(self) -> bool {
+        unsafe {
+            match self.element
+                      .get_unsigned_integer_attribute_for_layout(BorderUnsignedIntegerAttribute) {
+                None | Some(0) => false,
+                _ => true,
+            }
+        }
+    }
 }
 
 impl<'le> TElementAttributes for LayoutElement<'le> {
@@ -594,6 +607,18 @@ impl<'le> TElementAttributes for LayoutElement<'le> {
             self.element.get_integer_attribute_for_layout(integer_attribute)
         }
     }
+
+    fn get_unsigned_integer_attribute(self, attribute: UnsignedIntegerAttribute) -> Option<u32> {
+        unsafe {
+            self.element.get_unsigned_integer_attribute_for_layout(attribute)
+        }
+    }
+
+    fn get_simple_color_attribute(self, attribute: SimpleColorAttribute) -> Option<RGBA> {
+        unsafe {
+            self.element.get_simple_color_attribute_for_layout(attribute)
+        }
+    }
 }
 
 fn get_content(content_list: &content::T) -> String {
@@ -913,6 +938,18 @@ impl<'ln> ThreadSafeLayoutNode<'ln> {
         }
     }
 
+    pub fn get_unsigned_integer_attribute(self, attribute: UnsignedIntegerAttribute)
+                                          -> Option<u32> {
+        unsafe {
+            match ElementCast::to_js(self.get_jsmanaged()) {
+                Some(element) => {
+                    (*element.unsafe_get()).get_unsigned_integer_attribute_for_layout(attribute)
+                }
+                None => panic!("not an element!")
+            }
+        }
+    }
+
     /// Get the description of how to account for recent style changes.
     /// This is a simple bitfield and fine to copy by value.
     pub fn restyle_damage(self) -> RestyleDamage {
diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index afd329137c0..b877d022c2e 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -32,6 +32,7 @@ use dom::bindings::utils::{Reflectable, Reflector, WindowProxyHandler};
 use dom::node::{Node, TrustedNodeAddress};
 
 use collections::hash::{Hash, Hasher};
+use cssparser::RGBA;
 use geom::rect::Rect;
 use html5ever::tree_builder::QuirksMode;
 use hyper::header::Headers;
@@ -48,7 +49,7 @@ use script_traits::UntrustedNodeAddress;
 use servo_msg::compositor_msg::ScriptListener;
 use servo_msg::constellation_msg::ConstellationChan;
 use servo_util::smallvec::{SmallVec1, SmallVec};
-use servo_util::str::LengthOrPercentageOrAuto;
+use servo_util::str::{LengthOrPercentageOrAuto};
 use std::cell::{Cell, RefCell};
 use std::collections::HashMap;
 use std::comm::{Receiver, Sender};
@@ -214,6 +215,7 @@ no_jsmanaged_fields!(LayoutChan)
 no_jsmanaged_fields!(WindowProxyHandler)
 no_jsmanaged_fields!(UntrustedNodeAddress)
 no_jsmanaged_fields!(LengthOrPercentageOrAuto)
+no_jsmanaged_fields!(RGBA)
 
 impl<'a> JSTraceable for &'a str {
     #[inline]
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index c4dc787ac26..4fdb8a9befd 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -61,6 +61,7 @@ use servo_util::namespace;
 use servo_util::str::{DOMString, split_html_space_chars};
 
 use html5ever::tree_builder::{QuirksMode, NoQuirks, LimitedQuirks, Quirks};
+use layout_interface::{LayoutChan, SetQuirksModeMsg};
 use string_cache::{Atom, QualName};
 use url::Url;
 
@@ -217,6 +218,15 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
 
     fn set_quirks_mode(self, mode: QuirksMode) {
         self.quirks_mode.set(mode);
+
+        match mode {
+            Quirks => {
+                let window = self.window.root();
+                let LayoutChan(ref layout_chan) = window.page().layout_chan;
+                layout_chan.send(SetQuirksModeMsg);
+            }
+            NoQuirks | LimitedQuirks => {}
+        }
     }
 
     fn set_last_modified(self, value: DOMString) {
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 1e55f9f73c2..69846d40543 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -15,8 +15,12 @@ use dom::bindings::codegen::Bindings::ElementBinding::ElementMethods;
 use dom::bindings::codegen::Bindings::EventBinding::EventMethods;
 use dom::bindings::codegen::Bindings::HTMLInputElementBinding::HTMLInputElementMethods;
 use dom::bindings::codegen::Bindings::NamedNodeMapBinding::NamedNodeMapMethods;
-use dom::bindings::codegen::InheritTypes::{ElementDerived, HTMLInputElementDerived, HTMLTableCellElementDerived};
-use dom::bindings::codegen::InheritTypes::{HTMLInputElementCast, NodeCast, EventTargetCast, ElementCast};
+use dom::bindings::codegen::InheritTypes::{ElementCast, ElementDerived, EventTargetCast};
+use dom::bindings::codegen::InheritTypes::{HTMLBodyElementDerived, HTMLInputElementCast};
+use dom::bindings::codegen::InheritTypes::{HTMLInputElementDerived, HTMLTableElementCast};
+use dom::bindings::codegen::InheritTypes::{HTMLTableElementDerived, HTMLTableCellElementDerived};
+use dom::bindings::codegen::InheritTypes::{HTMLTableRowElementDerived};
+use dom::bindings::codegen::InheritTypes::{HTMLTableSectionElementDerived, NodeCast};
 use dom::bindings::js::{MutNullableJS, JS, JSRef, Temporary, TemporaryPushable};
 use dom::bindings::js::{OptionalRootable, Root};
 use dom::bindings::utils::{Reflectable, Reflector};
@@ -29,22 +33,28 @@ use dom::document::{Document, DocumentHelpers, LayoutDocumentHelpers};
 use dom::domtokenlist::DOMTokenList;
 use dom::event::Event;
 use dom::eventtarget::{EventTarget, NodeTargetTypeId, EventTargetHelpers};
+use dom::htmlbodyelement::{HTMLBodyElement, HTMLBodyElementHelpers};
 use dom::htmlcollection::HTMLCollection;
 use dom::htmlinputelement::{HTMLInputElement, RawLayoutHTMLInputElementHelpers};
 use dom::htmlserializer::serialize;
+use dom::htmltableelement::{HTMLTableElement, HTMLTableElementHelpers};
 use dom::htmltablecellelement::{HTMLTableCellElement, HTMLTableCellElementHelpers};
-use dom::node::{CLICK_IN_PROGRESS, ElementNodeTypeId, Node, NodeHelpers, NodeIterator};
-use dom::node::{document_from_node, window_from_node, LayoutNodeHelpers, NodeStyleDamaged};
-use dom::node::{OtherNodeDamage};
+use dom::htmltablerowelement::{HTMLTableRowElement, HTMLTableRowElementHelpers};
+use dom::htmltablesectionelement::{HTMLTableSectionElement, HTMLTableSectionElementHelpers};
+use dom::node::{CLICK_IN_PROGRESS, ElementNodeTypeId, LayoutNodeHelpers, Node, NodeHelpers};
+use dom::node::{NodeIterator, NodeStyleDamaged, OtherNodeDamage, document_from_node};
+use dom::node::{window_from_node};
 use dom::nodelist::NodeList;
 use dom::virtualmethods::{VirtualMethods, vtable_for};
 use devtools_traits::AttrInfo;
-use style::{IntegerAttribute, LengthAttribute, SizeIntegerAttribute, WidthLengthAttribute};
-use style::{matches, parse_selector_list_from_str};
-use style;
+use style::{mod, AuthorOrigin, BgColorSimpleColorAttribute, BorderUnsignedIntegerAttribute};
+use style::{ColSpanUnsignedIntegerAttribute, IntegerAttribute, LengthAttribute, ParserContext};
+use style::{SimpleColorAttribute, SizeIntegerAttribute, UnsignedIntegerAttribute};
+use style::{WidthLengthAttribute, matches};
 use servo_util::namespace;
 use servo_util::str::{DOMString, LengthOrPercentageOrAuto};
 
+use cssparser::RGBA;
 use std::ascii::AsciiExt;
 use std::cell::{Ref, RefMut};
 use std::default::Default;
@@ -201,6 +211,10 @@ pub trait RawLayoutElementHelpers {
     unsafe fn get_integer_attribute_for_layout(&self, integer_attribute: IntegerAttribute)
                                                -> Option<i32>;
     unsafe fn get_checked_state_for_layout(&self) -> bool;
+    unsafe fn get_unsigned_integer_attribute_for_layout(&self, attribute: UnsignedIntegerAttribute)
+                                                        -> Option<u32>;
+    unsafe fn get_simple_color_attribute_for_layout(&self, attribute: SimpleColorAttribute)
+                                                    -> Option<RGBA>;
     fn local_name<'a>(&'a self) -> &'a Atom;
     fn namespace<'a>(&'a self) -> &'a Namespace;
     fn style_attribute<'a>(&'a self) -> &'a DOMRefCell<Option<style::PropertyDeclarationBlock>>;
@@ -285,11 +299,15 @@ impl RawLayoutElementHelpers for Element {
                                               -> LengthOrPercentageOrAuto {
         match length_attribute {
             WidthLengthAttribute => {
-                if !self.is_htmltablecellelement() {
-                    panic!("I'm not a table cell!")
+                if self.is_htmltableelement() {
+                    let this: &HTMLTableElement = mem::transmute(self);
+                    this.get_width()
+                } else if self.is_htmltablecellelement() {
+                    let this: &HTMLTableCellElement = mem::transmute(self);
+                    this.get_width()
+                } else {
+                    panic!("I'm not a table or table cell!")
                 }
-                let this: &HTMLTableCellElement = mem::transmute(self);
-                this.get_width()
             }
         }
     }
@@ -319,6 +337,61 @@ impl RawLayoutElementHelpers for Element {
         this.get_checked_state_for_layout()
     }
 
+    unsafe fn get_unsigned_integer_attribute_for_layout(&self,
+                                                        attribute: UnsignedIntegerAttribute)
+                                                        -> Option<u32> {
+        match attribute {
+            BorderUnsignedIntegerAttribute => {
+                if self.is_htmltableelement() {
+                    let this: &HTMLTableElement = mem::transmute(self);
+                    this.get_border()
+                } else {
+                    // Don't panic since `:-servo-nonzero-border` can cause this to be called on
+                    // arbitrary elements.
+                    None
+                }
+            }
+            ColSpanUnsignedIntegerAttribute => {
+                if self.is_htmltablecellelement() {
+                    let this: &HTMLTableCellElement = mem::transmute(self);
+                    this.get_colspan()
+                } else {
+                    // Don't panic since `display` can cause this to be called on arbitrary
+                    // elements.
+                    None
+                }
+            }
+        }
+    }
+
+    #[inline]
+    #[allow(unrooted_must_root)]
+    unsafe fn get_simple_color_attribute_for_layout(&self, attribute: SimpleColorAttribute)
+                                                    -> Option<RGBA> {
+        match attribute {
+            BgColorSimpleColorAttribute => {
+                if self.is_htmlbodyelement() {
+                    let this: &HTMLBodyElement = mem::transmute(self);
+                    this.get_background_color()
+                } else if self.is_htmltableelement() {
+                    let this: &HTMLTableElement = mem::transmute(self);
+                    this.get_background_color()
+                } else if self.is_htmltablecellelement() {
+                    let this: &HTMLTableCellElement = mem::transmute(self);
+                    this.get_background_color()
+                } else if self.is_htmltablerowelement() {
+                    let this: &HTMLTableRowElement = mem::transmute(self);
+                    this.get_background_color()
+                } else if self.is_htmltablesectionelement() {
+                    let this: &HTMLTableSectionElement = mem::transmute(self);
+                    this.get_background_color()
+                } else {
+                    None
+                }
+            }
+        }
+    }
+
     // Getters used in components/layout/wrapper.rs
 
     fn local_name<'a>(&'a self) -> &'a Atom {
@@ -947,7 +1020,10 @@ impl<'a> ElementMethods for JSRef<'a, Element> {
 
     // http://dom.spec.whatwg.org/#dom-element-matches
     fn Matches(self, selectors: DOMString) -> Fallible<bool> {
-        match parse_selector_list_from_str(selectors.as_slice()) {
+        let parser_context = ParserContext {
+            origin: AuthorOrigin,
+        };
+        match style::parse_selector_list_from_str(&parser_context, selectors.as_slice()) {
             Err(()) => Err(Syntax),
             Ok(ref selectors) => {
                 let root: JSRef<Node> = NodeCast::from_ref(self);
@@ -1222,6 +1298,17 @@ impl<'a> style::TElement<'a> for JSRef<'a, Element> {
             }
         }
     }
+    fn has_nonzero_border(self) -> bool {
+        match HTMLTableElementCast::to_ref(self) {
+            None => false,
+            Some(this) => {
+                match this.get_border() {
+                    None | Some(0) => false,
+                    Some(_) => true,
+                }
+            }
+        }
+    }
 }
 
 pub trait ActivationElementHelpers<'a> {
diff --git a/components/script/dom/htmlbodyelement.rs b/components/script/dom/htmlbodyelement.rs
index d088a6b8626..917b02913a7 100644
--- a/components/script/dom/htmlbodyelement.rs
+++ b/components/script/dom/htmlbodyelement.rs
@@ -2,11 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::attr::Attr;
-use dom::attr::AttrHelpers;
+use dom::attr::{Attr, AttrHelpers};
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
-use dom::bindings::codegen::Bindings::HTMLBodyElementBinding;
-use dom::bindings::codegen::Bindings::HTMLBodyElementBinding::HTMLBodyElementMethods;
+use dom::bindings::codegen::Bindings::HTMLBodyElementBinding::{mod, HTMLBodyElementMethods};
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use dom::bindings::codegen::InheritTypes::EventTargetCast;
 use dom::bindings::codegen::InheritTypes::{HTMLBodyElementDerived, HTMLElementCast};
@@ -19,11 +17,14 @@ use dom::htmlelement::HTMLElement;
 use dom::node::{Node, ElementNodeTypeId, window_from_node};
 use dom::virtualmethods::VirtualMethods;
 
-use servo_util::str::DOMString;
+use cssparser::RGBA;
+use servo_util::str::{mod, DOMString};
+use std::cell::Cell;
 
 #[dom_struct]
 pub struct HTMLBodyElement {
-    htmlelement: HTMLElement
+    htmlelement: HTMLElement,
+    background_color: Cell<Option<RGBA>>,
 }
 
 impl HTMLBodyElementDerived for EventTarget {
@@ -33,14 +34,20 @@ impl HTMLBodyElementDerived for EventTarget {
 }
 
 impl HTMLBodyElement {
-    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLBodyElement {
+    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+                     -> HTMLBodyElement {
         HTMLBodyElement {
-            htmlelement: HTMLElement::new_inherited(HTMLBodyElementTypeId, localName, prefix, document)
+            htmlelement: HTMLElement::new_inherited(HTMLBodyElementTypeId,
+                                                    localName,
+                                                    prefix,
+                                                    document),
+            background_color: Cell::new(None),
         }
     }
 
     #[allow(unrooted_must_root)]
-    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> Temporary<HTMLBodyElement> {
+    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+               -> Temporary<HTMLBodyElement> {
         let element = HTMLBodyElement::new_inherited(localName, prefix, document);
         Node::reflect_node(box element, document, HTMLBodyElementBinding::Wrap)
     }
@@ -58,6 +65,16 @@ impl<'a> HTMLBodyElementMethods for JSRef<'a, HTMLBodyElement> {
     }
 }
 
+pub trait HTMLBodyElementHelpers {
+    fn get_background_color(&self) -> Option<RGBA>;
+}
+
+impl HTMLBodyElementHelpers for HTMLBodyElement {
+    fn get_background_color(&self) -> Option<RGBA> {
+        self.background_color.get()
+    }
+}
+
 impl<'a> VirtualMethods for JSRef<'a, HTMLBodyElement> {
     fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
         let element: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
@@ -91,6 +108,25 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLBodyElement> {
                                                   name.slice_from(2),
                                                   attr.value().as_slice().to_string());
         }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => {
+                self.background_color.set(str::parse_legacy_color(attr.value().as_slice()).ok())
+            }
+            _ => {}
+        }
+    }
+
+    fn before_remove_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.before_remove_attr(attr),
+            _ => {}
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => self.background_color.set(None),
+            _ => {}
+        }
     }
 }
 
diff --git a/components/script/dom/htmltablecellelement.rs b/components/script/dom/htmltablecellelement.rs
index cee07540301..9ca84b0e70f 100644
--- a/components/script/dom/htmltablecellelement.rs
+++ b/components/script/dom/htmltablecellelement.rs
@@ -2,8 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::attr::Attr;
-use dom::attr::AttrHelpers;
+use dom::attr::{Attr, AttrHelpers};
 use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLTableCellElementDerived};
 use dom::bindings::js::JSRef;
 use dom::bindings::utils::{Reflectable, Reflector};
@@ -15,13 +14,15 @@ use dom::htmlelement::HTMLElement;
 use dom::node::ElementNodeTypeId;
 use dom::virtualmethods::VirtualMethods;
 
-use servo_util::str::{AutoLpa, DOMString, LengthOrPercentageOrAuto};
-use servo_util::str;
+use cssparser::RGBA;
+use servo_util::str::{mod, AutoLpa, DOMString, LengthOrPercentageOrAuto};
 use std::cell::Cell;
 
 #[dom_struct]
 pub struct HTMLTableCellElement {
     htmlelement: HTMLElement,
+    background_color: Cell<Option<RGBA>>,
+    colspan: Cell<Option<u32>>,
     width: Cell<LengthOrPercentageOrAuto>,
 }
 
@@ -36,10 +37,16 @@ impl HTMLTableCellElementDerived for EventTarget {
 }
 
 impl HTMLTableCellElement {
-    pub fn new_inherited(type_id: ElementTypeId, tag_name: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLTableCellElement {
+    pub fn new_inherited(type_id: ElementTypeId,
+                         tag_name: DOMString,
+                         prefix: Option<DOMString>,
+                         document: JSRef<Document>)
+                         -> HTMLTableCellElement {
         HTMLTableCellElement {
             htmlelement: HTMLElement::new_inherited(type_id, tag_name, prefix, document),
-            width: Cell::new(AutoLpa)
+            background_color: Cell::new(None),
+            colspan: Cell::new(None),
+            width: Cell::new(AutoLpa),
         }
     }
 
@@ -50,10 +57,20 @@ impl HTMLTableCellElement {
 }
 
 pub trait HTMLTableCellElementHelpers {
+    fn get_background_color(&self) -> Option<RGBA>;
+    fn get_colspan(&self) -> Option<u32>;
     fn get_width(&self) -> LengthOrPercentageOrAuto;
 }
 
 impl HTMLTableCellElementHelpers for HTMLTableCellElement {
+    fn get_background_color(&self) -> Option<RGBA> {
+        self.background_color.get()
+    }
+
+    fn get_colspan(&self) -> Option<u32> {
+        self.colspan.get()
+    }
+
     fn get_width(&self) -> LengthOrPercentageOrAuto {
         self.width.get()
     }
@@ -72,6 +89,12 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLTableCellElement> {
         }
 
         match attr.local_name() {
+            &atom!("bgcolor") => {
+                self.background_color.set(str::parse_legacy_color(attr.value().as_slice()).ok())
+            }
+            &atom!("colspan") => {
+                self.colspan.set(str::parse_unsigned_integer(attr.value().as_slice().chars()));
+            }
             &atom!("width") => self.width.set(str::parse_length(attr.value().as_slice())),
             _ => ()
         }
@@ -84,6 +107,8 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLTableCellElement> {
         }
 
         match attr.local_name() {
+            &atom!("bgcolor") => self.background_color.set(None),
+            &atom!("colspan") => self.colspan.set(None),
             &atom!("width") => self.width.set(AutoLpa),
             _ => ()
         }
diff --git a/components/script/dom/htmltableelement.rs b/components/script/dom/htmltableelement.rs
index 7dddf98bdc4..d2c9e723b78 100644
--- a/components/script/dom/htmltableelement.rs
+++ b/components/script/dom/htmltableelement.rs
@@ -2,10 +2,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::codegen::Bindings::HTMLTableElementBinding;
+use dom::attr::{Attr, AttrHelpers};
 use dom::bindings::codegen::Bindings::HTMLTableElementBinding::HTMLTableElementMethods;
-use dom::bindings::codegen::InheritTypes::{HTMLTableElementDerived, NodeCast, HTMLTableCaptionElementCast};
+use dom::bindings::codegen::Bindings::HTMLTableElementBinding;
 use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
+use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLTableCaptionElementCast};
+use dom::bindings::codegen::InheritTypes::{HTMLTableElementDerived, NodeCast};
 use dom::bindings::js::{JSRef, Temporary};
 use dom::bindings::utils::{Reflectable, Reflector};
 use dom::document::Document;
@@ -14,11 +16,18 @@ use dom::eventtarget::{EventTarget, NodeTargetTypeId};
 use dom::htmlelement::HTMLElement;
 use dom::htmltablecaptionelement::HTMLTableCaptionElement;
 use dom::node::{Node, NodeHelpers, ElementNodeTypeId};
-use servo_util::str::DOMString;
+use dom::virtualmethods::VirtualMethods;
+
+use cssparser::RGBA;
+use servo_util::str::{mod, AutoLpa, DOMString, LengthOrPercentageOrAuto};
+use std::cell::Cell;
 
 #[dom_struct]
 pub struct HTMLTableElement {
     htmlelement: HTMLElement,
+    background_color: Cell<Option<RGBA>>,
+    border: Cell<Option<u32>>,
+    width: Cell<LengthOrPercentageOrAuto>,
 }
 
 impl HTMLTableElementDerived for EventTarget {
@@ -28,14 +37,22 @@ impl HTMLTableElementDerived for EventTarget {
 }
 
 impl HTMLTableElement {
-    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLTableElement {
+    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+                     -> HTMLTableElement {
         HTMLTableElement {
-            htmlelement: HTMLElement::new_inherited(HTMLTableElementTypeId, localName, prefix, document)
+            htmlelement: HTMLElement::new_inherited(HTMLTableElementTypeId,
+                                                    localName,
+                                                    prefix,
+                                                    document),
+            background_color: Cell::new(None),
+            border: Cell::new(None),
+            width: Cell::new(AutoLpa),
         }
     }
 
     #[allow(unrooted_must_root)]
-    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> Temporary<HTMLTableElement> {
+    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+               -> Temporary<HTMLTableElement> {
         let element = HTMLTableElement::new_inherited(localName, prefix, document);
         Node::reflect_node(box element, document, HTMLTableElementBinding::Wrap)
     }
@@ -77,3 +94,66 @@ impl<'a> HTMLTableElementMethods for JSRef<'a, HTMLTableElement> {
         });
     }
 }
+
+pub trait HTMLTableElementHelpers {
+    fn get_background_color(&self) -> Option<RGBA>;
+    fn get_border(&self) -> Option<u32>;
+    fn get_width(&self) -> LengthOrPercentageOrAuto;
+}
+
+impl HTMLTableElementHelpers for HTMLTableElement {
+    fn get_background_color(&self) -> Option<RGBA> {
+        self.background_color.get()
+    }
+
+    fn get_border(&self) -> Option<u32> {
+        self.border.get()
+    }
+
+    fn get_width(&self) -> LengthOrPercentageOrAuto {
+        self.width.get()
+    }
+}
+
+impl<'a> VirtualMethods for JSRef<'a, HTMLTableElement> {
+    fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
+        let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
+        Some(htmlelement as &VirtualMethods)
+    }
+
+    fn after_set_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.after_set_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => {
+                self.background_color.set(str::parse_legacy_color(attr.value().as_slice()).ok())
+            }
+            &atom!("border") => {
+                // According to HTML5 § 14.3.9, invalid values map to 1px.
+                self.border.set(Some(str::parse_unsigned_integer(attr.value()
+                                                                     .as_slice()
+                                                                     .chars()).unwrap_or(1)))
+            }
+            &atom!("width") => self.width.set(str::parse_length(attr.value().as_slice())),
+            _ => ()
+        }
+    }
+
+    fn before_remove_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.before_remove_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => self.background_color.set(None),
+            &atom!("border") => self.border.set(None),
+            &atom!("width") => self.width.set(AutoLpa),
+            _ => ()
+        }
+    }
+}
+
diff --git a/components/script/dom/htmltablerowelement.rs b/components/script/dom/htmltablerowelement.rs
index 3edf4a0e64f..500c7d74472 100644
--- a/components/script/dom/htmltablerowelement.rs
+++ b/components/script/dom/htmltablerowelement.rs
@@ -2,8 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use dom::attr::{Attr, AttrHelpers};
 use dom::bindings::codegen::Bindings::HTMLTableRowElementBinding;
-use dom::bindings::codegen::InheritTypes::HTMLTableRowElementDerived;
+use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLTableRowElementDerived};
 use dom::bindings::js::{JSRef, Temporary};
 use dom::bindings::utils::{Reflectable, Reflector};
 use dom::document::Document;
@@ -11,11 +12,16 @@ use dom::element::HTMLTableRowElementTypeId;
 use dom::eventtarget::{EventTarget, NodeTargetTypeId};
 use dom::htmlelement::HTMLElement;
 use dom::node::{Node, ElementNodeTypeId};
-use servo_util::str::DOMString;
+use dom::virtualmethods::VirtualMethods;
+
+use cssparser::RGBA;
+use servo_util::str::{mod, DOMString};
+use std::cell::Cell;
 
 #[dom_struct]
 pub struct HTMLTableRowElement {
     htmlelement: HTMLElement,
+    background_color: Cell<Option<RGBA>>,
 }
 
 impl HTMLTableRowElementDerived for EventTarget {
@@ -25,9 +31,14 @@ impl HTMLTableRowElementDerived for EventTarget {
 }
 
 impl HTMLTableRowElement {
-    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLTableRowElement {
+    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+                     -> HTMLTableRowElement {
         HTMLTableRowElement {
-            htmlelement: HTMLElement::new_inherited(HTMLTableRowElementTypeId, localName, prefix, document)
+            htmlelement: HTMLElement::new_inherited(HTMLTableRowElementTypeId,
+                                                    localName,
+                                                    prefix,
+                                                    document),
+            background_color: Cell::new(None),
         }
     }
 
@@ -45,3 +56,47 @@ impl Reflectable for HTMLTableRowElement {
         self.htmlelement.reflector()
     }
 }
+
+pub trait HTMLTableRowElementHelpers {
+    fn get_background_color(&self) -> Option<RGBA>;
+}
+
+impl HTMLTableRowElementHelpers for HTMLTableRowElement {
+    fn get_background_color(&self) -> Option<RGBA> {
+        self.background_color.get()
+    }
+}
+
+impl<'a> VirtualMethods for JSRef<'a, HTMLTableRowElement> {
+    fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
+        let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
+        Some(htmlelement as &VirtualMethods)
+    }
+
+    fn after_set_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.after_set_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => {
+                self.background_color.set(str::parse_legacy_color(attr.value().as_slice()).ok())
+            }
+            _ => {}
+        }
+    }
+
+    fn before_remove_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.before_remove_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => self.background_color.set(None),
+            _ => {}
+        }
+    }
+}
+
diff --git a/components/script/dom/htmltablesectionelement.rs b/components/script/dom/htmltablesectionelement.rs
index d10e4b82b44..b191e21bde0 100644
--- a/components/script/dom/htmltablesectionelement.rs
+++ b/components/script/dom/htmltablesectionelement.rs
@@ -2,8 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use dom::attr::{Attr, AttrHelpers};
 use dom::bindings::codegen::Bindings::HTMLTableSectionElementBinding;
-use dom::bindings::codegen::InheritTypes::HTMLTableSectionElementDerived;
+use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLTableSectionElementDerived};
 use dom::bindings::js::{JSRef, Temporary};
 use dom::bindings::utils::{Reflectable, Reflector};
 use dom::document::Document;
@@ -11,11 +12,16 @@ use dom::element::HTMLTableSectionElementTypeId;
 use dom::eventtarget::{EventTarget, NodeTargetTypeId};
 use dom::htmlelement::HTMLElement;
 use dom::node::{Node, ElementNodeTypeId};
-use servo_util::str::DOMString;
+use dom::virtualmethods::VirtualMethods;
+
+use cssparser::RGBA;
+use servo_util::str::{mod, DOMString};
+use std::cell::Cell;
 
 #[dom_struct]
 pub struct HTMLTableSectionElement {
     htmlelement: HTMLElement,
+    background_color: Cell<Option<RGBA>>,
 }
 
 impl HTMLTableSectionElementDerived for EventTarget {
@@ -25,14 +31,20 @@ impl HTMLTableSectionElementDerived for EventTarget {
 }
 
 impl HTMLTableSectionElement {
-    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLTableSectionElement {
+    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+                     -> HTMLTableSectionElement {
         HTMLTableSectionElement {
-            htmlelement: HTMLElement::new_inherited(HTMLTableSectionElementTypeId, localName, prefix, document)
+            htmlelement: HTMLElement::new_inherited(HTMLTableSectionElementTypeId,
+                                                    localName,
+                                                    prefix,
+                                                    document),
+            background_color: Cell::new(None),
         }
     }
 
     #[allow(unrooted_must_root)]
-    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> Temporary<HTMLTableSectionElement> {
+    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>)
+               -> Temporary<HTMLTableSectionElement> {
         let element = HTMLTableSectionElement::new_inherited(localName, prefix, document);
         Node::reflect_node(box element, document, HTMLTableSectionElementBinding::Wrap)
     }
@@ -43,3 +55,47 @@ impl Reflectable for HTMLTableSectionElement {
         self.htmlelement.reflector()
     }
 }
+
+pub trait HTMLTableSectionElementHelpers {
+    fn get_background_color(&self) -> Option<RGBA>;
+}
+
+impl HTMLTableSectionElementHelpers for HTMLTableSectionElement {
+    fn get_background_color(&self) -> Option<RGBA> {
+        self.background_color.get()
+    }
+}
+
+impl<'a> VirtualMethods for JSRef<'a, HTMLTableSectionElement> {
+    fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
+        let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
+        Some(htmlelement as &VirtualMethods)
+    }
+
+    fn after_set_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.after_set_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => {
+                self.background_color.set(str::parse_legacy_color(attr.value().as_slice()).ok())
+            }
+            _ => {}
+        }
+    }
+
+    fn before_remove_attr(&self, attr: JSRef<Attr>) {
+        match self.super_type() {
+            Some(ref s) => s.before_remove_attr(attr),
+            _ => ()
+        }
+
+        match attr.local_name() {
+            &atom!("bgcolor") => self.background_color.set(None),
+            _ => {}
+        }
+    }
+}
+
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index ecfccf8aefc..0871a266df3 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -50,7 +50,7 @@ use devtools_traits::NodeInfo;
 use script_traits::UntrustedNodeAddress;
 use servo_util::geometry::Au;
 use servo_util::str::{DOMString, null_str_as_empty};
-use style::{parse_selector_list_from_str, matches, SelectorList};
+use style::{matches, AuthorOrigin, ParserContext, SelectorList};
 
 use js::jsapi::{JSContext, JSObject, JSTracer, JSRuntime};
 use js::jsfriendapi;
@@ -60,8 +60,7 @@ use std::cell::{Cell, RefCell, Ref, RefMut};
 use std::default::Default;
 use std::iter::{FilterMap, Peekable};
 use std::mem;
-use style;
-use style::ComputedValues;
+use style::{mod, ComputedValues};
 use sync::Arc;
 use uuid;
 use string_cache::QualName;
@@ -741,7 +740,10 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
     // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
     fn query_selector(self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
         // Step 1.
-        match parse_selector_list_from_str(selectors.as_slice()) {
+        let parser_context = ParserContext {
+            origin: AuthorOrigin,
+        };
+        match style::parse_selector_list_from_str(&parser_context, selectors.as_slice()) {
             // Step 2.
             Err(()) => return Err(Syntax),
             // Step 3.
@@ -758,11 +760,15 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
     /// Get an iterator over all nodes which match a set of selectors
     /// Be careful not to do anything which may manipulate the DOM tree whilst iterating, otherwise
     /// the iterator may be invalidated
-    unsafe fn query_selector_iter(self, selectors: DOMString) -> Fallible<QuerySelectorIterator<'a>> {
+    unsafe fn query_selector_iter(self, selectors: DOMString)
+                                  -> Fallible<QuerySelectorIterator<'a>> {
         // Step 1.
         let nodes;
         let root = self.ancestors().last().unwrap_or(self.clone());
-        match parse_selector_list_from_str(selectors.as_slice()) {
+        let parser_context = ParserContext {
+            origin: AuthorOrigin,
+        };
+        match style::parse_selector_list_from_str(&parser_context, selectors.as_slice()) {
             // Step 2.
             Err(()) => return Err(Syntax),
             // Step 3.
diff --git a/components/script/dom/virtualmethods.rs b/components/script/dom/virtualmethods.rs
index a90055bc50d..94a74124eca 100644
--- a/components/script/dom/virtualmethods.rs
+++ b/components/script/dom/virtualmethods.rs
@@ -22,7 +22,10 @@ use dom::bindings::codegen::InheritTypes::HTMLOptionElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLScriptElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLSelectElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLStyleElementCast;
+use dom::bindings::codegen::InheritTypes::HTMLTableElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLTableCellElementCast;
+use dom::bindings::codegen::InheritTypes::HTMLTableRowElementCast;
+use dom::bindings::codegen::InheritTypes::HTMLTableSectionElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLTextAreaElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLTitleElementCast;
 use dom::bindings::js::JSRef;
@@ -46,7 +49,10 @@ use dom::element::HTMLScriptElementTypeId;
 use dom::element::HTMLSelectElementTypeId;
 use dom::element::HTMLStyleElementTypeId;
 use dom::element::HTMLTableDataCellElementTypeId;
+use dom::element::HTMLTableElementTypeId;
 use dom::element::HTMLTableHeaderCellElementTypeId;
+use dom::element::HTMLTableRowElementTypeId;
+use dom::element::HTMLTableSectionElementTypeId;
 use dom::element::HTMLTextAreaElementTypeId;
 use dom::element::HTMLTitleElementTypeId;
 use dom::event::Event;
@@ -67,7 +73,10 @@ use dom::htmloptionelement::HTMLOptionElement;
 use dom::htmlscriptelement::HTMLScriptElement;
 use dom::htmlselectelement::HTMLSelectElement;
 use dom::htmlstyleelement::HTMLStyleElement;
+use dom::htmltableelement::HTMLTableElement;
 use dom::htmltablecellelement::HTMLTableCellElement;
+use dom::htmltablerowelement::HTMLTableRowElement;
+use dom::htmltablesectionelement::HTMLTableSectionElement;
 use dom::htmltextareaelement::HTMLTextAreaElement;
 use dom::htmltitleelement::HTMLTitleElement;
 use dom::node::{Node, NodeHelpers, ElementNodeTypeId, CloneChildrenFlag};
@@ -226,9 +235,25 @@ pub fn vtable_for<'a>(node: &'a JSRef<'a, Node>) -> &'a VirtualMethods + 'a {
             let element: &'a JSRef<'a, HTMLStyleElement> = HTMLStyleElementCast::to_borrowed_ref(node).unwrap();
             element as &'a VirtualMethods + 'a
         }
+        ElementNodeTypeId(HTMLTableElementTypeId) => {
+            let element: &'a JSRef<'a, HTMLTableElement> =
+                HTMLTableElementCast::to_borrowed_ref(node).unwrap();
+            element as &'a VirtualMethods + 'a
+        }
         ElementNodeTypeId(HTMLTableDataCellElementTypeId) |
         ElementNodeTypeId(HTMLTableHeaderCellElementTypeId) => {
-            let element: &'a JSRef<'a, HTMLTableCellElement> = HTMLTableCellElementCast::to_borrowed_ref(node).unwrap();
+            let element: &'a JSRef<'a, HTMLTableCellElement> =
+                HTMLTableCellElementCast::to_borrowed_ref(node).unwrap();
+            element as &'a VirtualMethods + 'a
+        }
+        ElementNodeTypeId(HTMLTableRowElementTypeId) => {
+            let element: &'a JSRef<'a, HTMLTableRowElement> =
+                HTMLTableRowElementCast::to_borrowed_ref(node).unwrap();
+            element as &'a VirtualMethods + 'a
+        }
+        ElementNodeTypeId(HTMLTableSectionElementTypeId) => {
+            let element: &'a JSRef<'a, HTMLTableSectionElement> =
+                HTMLTableSectionElementCast::to_borrowed_ref(node).unwrap();
             element as &'a VirtualMethods + 'a
         }
         ElementNodeTypeId(HTMLTextAreaElementTypeId) => {
diff --git a/components/script/layout_interface.rs b/components/script/layout_interface.rs
index c3afb15c057..0f3f4fbacbf 100644
--- a/components/script/layout_interface.rs
+++ b/components/script/layout_interface.rs
@@ -29,6 +29,9 @@ pub enum Msg {
     /// Adds the given stylesheet to the document.
     LoadStylesheetMsg(Url),
 
+    /// Puts a document into quirks mode, causing the quirks mode stylesheet to be loaded.
+    SetQuirksModeMsg,
+
     /// Requests a reflow.
     ReflowMsg(Box<Reflow>),
 
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index bb04bd528af..edede8178fc 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -121,7 +121,7 @@ dependencies = [
 [[package]]
 name = "cssparser"
 version = "0.1.0"
-source = "git+https://github.com/servo/rust-cssparser#cbbfd66f794bd019bbdeaefc88b29eff455b62e5"
+source = "git+https://github.com/servo/rust-cssparser#3f98f1308b769b5d61efc6c133ac520df2b074ac"
 dependencies = [
  "encoding 0.2.0 (git+https://github.com/lifthrasiir/rust-encoding)",
 ]
@@ -410,6 +410,7 @@ dependencies = [
 name = "layout"
 version = "0.0.1"
 dependencies = [
+ "cssparser 0.1.0 (git+https://github.com/servo/rust-cssparser)",
  "encoding 0.2.0 (git+https://github.com/lifthrasiir/rust-encoding)",
  "geom 0.1.0 (git+https://github.com/servo/rust-geom)",
  "gfx 0.0.1",
@@ -672,6 +673,7 @@ dependencies = [
 name = "util"
 version = "0.0.1"
 dependencies = [
+ "cssparser 0.1.0 (git+https://github.com/servo/rust-cssparser)",
  "geom 0.1.0 (git+https://github.com/servo/rust-geom)",
  "layers 0.1.0 (git+https://github.com/servo/rust-layers)",
  "string_cache 0.0.0 (git+https://github.com/servo/string-cache)",
diff --git a/components/style/legacy.rs b/components/style/legacy.rs
index f99314667b8..6b22d70ca76 100644
--- a/components/style/legacy.rs
+++ b/components/style/legacy.rs
@@ -5,6 +5,17 @@
 //! Legacy presentational attributes defined in the HTML5 specification: `<td width>`,
 //! `<input size>`, and so forth.
 
+use node::{TElement, TElementAttributes, TNode};
+use properties::{BackgroundColorDeclaration, BorderBottomWidthDeclaration};
+use properties::{BorderLeftWidthDeclaration, BorderRightWidthDeclaration};
+use properties::{BorderTopWidthDeclaration, SpecifiedValue, WidthDeclaration, specified};
+use selector_matching::{DeclarationBlock, Stylist};
+
+use cssparser::RGBAColor;
+use servo_util::geometry::Au;
+use servo_util::smallvec::VecLike;
+use servo_util::str::{AutoLpa, LengthLpa, PercentageLpa};
+
 /// Legacy presentational attributes that take a length as defined in HTML5 § 2.4.4.4.
 pub enum LengthAttribute {
     /// `<td width>`
@@ -17,3 +28,187 @@ pub enum IntegerAttribute {
     SizeIntegerAttribute,
 }
 
+/// Legacy presentational attributes that take a nonnegative integer as defined in HTML5 § 2.4.4.2.
+pub enum UnsignedIntegerAttribute {
+    /// `<td border>`
+    BorderUnsignedIntegerAttribute,
+    /// `<td colspan>`
+    ColSpanUnsignedIntegerAttribute,
+}
+
+/// Legacy presentational attributes that take a simple color as defined in HTML5 § 2.4.6.
+pub enum SimpleColorAttribute {
+    /// `<body bgcolor>`
+    BgColorSimpleColorAttribute,
+}
+
+/// Extension methods for `Stylist` that cause rules to be synthesized for legacy attributes.
+pub trait PresentationalHintSynthesis {
+    /// Synthesizes rules from various HTML attributes (mostly legacy junk from HTML4) that confer
+    /// *presentational hints* as defined in the HTML5 specification. This handles stuff like
+    /// `<body bgcolor>`, `<input size>`, `<td width>`, and so forth.
+    ///
+    /// NB: Beware! If you add an attribute to this list, be sure to add it to
+    /// `common_style_affecting_attributes` or `rare_style_affecting_attributes` as appropriate. If
+    /// you don't, you risk strange random nondeterministic failures due to false positives in
+    /// style sharing.
+    fn synthesize_presentational_hints_for_legacy_attributes<'a,E,N,V>(
+                                                             &self,
+                                                             node: &N,
+                                                             matching_rules_list: &mut V,
+                                                             shareable: &mut bool)
+                                                             where E: TElement<'a> +
+                                                                      TElementAttributes,
+                                                                   N: TNode<'a,E>,
+                                                                   V: VecLike<DeclarationBlock>;
+    /// Synthesizes rules for the legacy `bgcolor` attribute.
+    fn synthesize_presentational_hint_for_legacy_background_color_attribute<'a,E,V>(
+                                                                            &self,
+                                                                            element: E,
+                                                                            matching_rules_list:
+                                                                                &mut V,
+                                                                            shareable: &mut bool)
+                                                                            where
+                                                                            E: TElement<'a> +
+                                                                               TElementAttributes,
+                                                                            V: VecLike<
+                                                                                DeclarationBlock>;
+    /// Synthesizes rules for the legacy `border` attribute.
+    fn synthesize_presentational_hint_for_legacy_border_attribute<'a,E,V>(
+                                                                  &self,
+                                                                  element: E,
+                                                                  matching_rules_list: &mut V,
+                                                                  shareable: &mut bool)
+                                                                  where
+                                                                    E: TElement<'a> +
+                                                                       TElementAttributes,
+                                                                    V: VecLike<DeclarationBlock>;
+}
+
+impl PresentationalHintSynthesis for Stylist {
+    fn synthesize_presentational_hints_for_legacy_attributes<'a,E,N,V>(
+                                                             &self,
+                                                             node: &N,
+                                                             matching_rules_list: &mut V,
+                                                             shareable: &mut bool)
+                                                             where E: TElement<'a> +
+                                                                      TElementAttributes,
+                                                                   N: TNode<'a,E>,
+                                                                   V: VecLike<DeclarationBlock> {
+        let element = node.as_element();
+        match element.get_local_name() {
+            name if *name == atom!("td") => {
+                match element.get_length_attribute(WidthLengthAttribute) {
+                    AutoLpa => {}
+                    PercentageLpa(percentage) => {
+                        let width_value = specified::LPA_Percentage(percentage);
+                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                                WidthDeclaration(SpecifiedValue(width_value))));
+                        *shareable = false
+                    }
+                    LengthLpa(length) => {
+                        let width_value = specified::LPA_Length(specified::Au_(length));
+                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                                WidthDeclaration(SpecifiedValue(width_value))));
+                        *shareable = false
+                    }
+                }
+                self.synthesize_presentational_hint_for_legacy_background_color_attribute(
+                    element,
+                    matching_rules_list,
+                    shareable);
+                self.synthesize_presentational_hint_for_legacy_border_attribute(
+                    element,
+                    matching_rules_list,
+                    shareable);
+            }
+            name if *name == atom!("table") => {
+                self.synthesize_presentational_hint_for_legacy_background_color_attribute(
+                    element,
+                    matching_rules_list,
+                    shareable);
+                self.synthesize_presentational_hint_for_legacy_border_attribute(
+                    element,
+                    matching_rules_list,
+                    shareable);
+            }
+            name if *name == atom!("body") || *name == atom!("tr") || *name == atom!("thead") ||
+                    *name == atom!("tbody") || *name == atom!("tfoot") => {
+                self.synthesize_presentational_hint_for_legacy_background_color_attribute(
+                    element,
+                    matching_rules_list,
+                    shareable);
+            }
+            name if *name == atom!("input") => {
+                match element.get_integer_attribute(SizeIntegerAttribute) {
+                    Some(value) if value != 0 => {
+                        // Per HTML 4.01 § 17.4, this value is in characters if `type` is `text` or
+                        // `password` and in pixels otherwise.
+                        //
+                        // FIXME(pcwalton): More use of atoms, please!
+                        let value = match element.get_attr(&ns!(""), &atom!("type")) {
+                            Some("text") | Some("password") => {
+                                specified::ServoCharacterWidth(value)
+                            }
+                            _ => specified::Au_(Au::from_px(value as int)),
+                        };
+                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                                WidthDeclaration(SpecifiedValue(specified::LPA_Length(
+                                            value)))));
+                        *shareable = false
+                    }
+                    Some(_) | None => {}
+                }
+            }
+            _ => {}
+        }
+    }
+
+    fn synthesize_presentational_hint_for_legacy_background_color_attribute<'a,E,V>(
+                                                                            &self,
+                                                                            element: E,
+                                                                            matching_rules_list:
+                                                                                &mut V,
+                                                                            shareable: &mut bool)
+                                                                            where
+                                                                            E: TElement<'a> +
+                                                                               TElementAttributes,
+                                                                            V: VecLike<
+                                                                                DeclarationBlock> {
+        match element.get_simple_color_attribute(BgColorSimpleColorAttribute) {
+            None => {}
+            Some(color) => {
+                matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                        BackgroundColorDeclaration(SpecifiedValue(RGBAColor(color)))));
+                *shareable = false
+            }
+        }
+    }
+
+    fn synthesize_presentational_hint_for_legacy_border_attribute<'a,E,V>(
+                                                                  &self,
+                                                                  element: E,
+                                                                  matching_rules_list: &mut V,
+                                                                  shareable: &mut bool)
+                                                                  where
+                                                                    E: TElement<'a> +
+                                                                       TElementAttributes,
+                                                                    V: VecLike<DeclarationBlock> {
+        match element.get_unsigned_integer_attribute(BorderUnsignedIntegerAttribute) {
+            None => {}
+            Some(length) => {
+                let width_value = specified::Au_(Au::from_px(length as int));
+                matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                        BorderTopWidthDeclaration(SpecifiedValue(width_value))));
+                matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                        BorderLeftWidthDeclaration(SpecifiedValue(width_value))));
+                matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                        BorderBottomWidthDeclaration(SpecifiedValue(width_value))));
+                matching_rules_list.vec_push(DeclarationBlock::from_declaration(
+                        BorderRightWidthDeclaration(SpecifiedValue(width_value))));
+                *shareable = false
+            }
+        }
+    }
+}
+
diff --git a/components/style/lib.rs b/components/style/lib.rs
index e6e0e77f7a5..d28ba62b112 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -41,7 +41,8 @@ pub use selector_matching::{DeclarationBlock, CommonStyleAffectingAttributes};
 pub use selector_matching::{CommonStyleAffectingAttributeInfo, CommonStyleAffectingAttributeMode};
 pub use selector_matching::{AttrIsPresentMode, AttrIsEqualMode};
 pub use selector_matching::{matches, matches_simple_selector, common_style_affecting_attributes};
-pub use selector_matching::{RECOMMENDED_SELECTOR_BLOOM_FILTER_SIZE,SELECTOR_WHITESPACE};
+pub use selector_matching::{rare_style_affecting_attributes};
+pub use selector_matching::{RECOMMENDED_SELECTOR_BLOOM_FILTER_SIZE, SELECTOR_WHITESPACE};
 pub use properties::{cascade, cascade_anonymous, computed};
 pub use properties::{PropertyDeclaration, ComputedValues, computed_values, style_structs};
 pub use properties::{PropertyDeclarationBlock, parse_style_attribute};  // Style attributes
@@ -49,11 +50,14 @@ pub use properties::{CSSFloat, DeclaredValue, PropertyDeclarationParseResult};
 pub use properties::{Angle, AngleOrCorner, AngleAoc, CornerAoc};
 pub use properties::{Left, Right, Bottom, Top};
 pub use node::{TElement, TElementAttributes, TNode};
-pub use selectors::{PseudoElement, Before, After, SelectorList, parse_selector_list_from_str};
+pub use selectors::{PseudoElement, Before, After, ParserContext, SelectorList};
 pub use selectors::{AttrSelector, NamespaceConstraint, SpecificNamespace, AnyNamespace};
-pub use selectors::{SimpleSelector,LocalNameSelector};
+pub use selectors::{SimpleSelector, LocalNameSelector, parse_selector_list_from_str};
 pub use cssparser::{Color, RGBA};
-pub use legacy::{IntegerAttribute, LengthAttribute, SizeIntegerAttribute, WidthLengthAttribute};
+pub use legacy::{BgColorSimpleColorAttribute, BorderUnsignedIntegerAttribute};
+pub use legacy::{ColSpanUnsignedIntegerAttribute, IntegerAttribute, LengthAttribute};
+pub use legacy::{SimpleColorAttribute, SizeIntegerAttribute, UnsignedIntegerAttribute};
+pub use legacy::{WidthLengthAttribute};
 pub use font_face::{Source, LocalSource, UrlSource_};
 
 mod stylesheets;
diff --git a/components/style/media_queries.rs b/components/style/media_queries.rs
index 33d5203064e..f014be0114d 100644
--- a/components/style/media_queries.rs
+++ b/components/style/media_queries.rs
@@ -8,12 +8,14 @@ use cssparser::ast::*;
 
 use errors::{ErrorLoggerIterator, log_css_error};
 use geom::size::TypedSize2D;
-use stylesheets::{CSSRule, CSSMediaRule, parse_style_rule, parse_nested_at_rule};
+use selectors::ParserContext;
+use stylesheets::{CSSRule, CSSMediaRule};
 use namespaces::NamespaceMap;
 use parsing_utils::{BufferedIter, ParserIter};
 use properties::common_types::*;
 use properties::longhands;
 use servo_util::geometry::ViewportPx;
+use stylesheets;
 use url::Url;
 
 pub struct MediaRule {
@@ -95,8 +97,11 @@ impl Device {
     }
 }
 
-pub fn parse_media_rule(rule: AtRule, parent_rules: &mut Vec<CSSRule>,
-                        namespaces: &NamespaceMap, base_url: &Url) {
+pub fn parse_media_rule(context: &ParserContext,
+                        rule: AtRule,
+                        parent_rules: &mut Vec<CSSRule>,
+                        namespaces: &NamespaceMap,
+                        base_url: &Url) {
     let media_queries = parse_media_query_list(rule.prelude.as_slice());
     let block = match rule.block {
         Some(block) => block,
@@ -108,9 +113,17 @@ pub fn parse_media_rule(rule: AtRule, parent_rules: &mut Vec<CSSRule>,
     let mut rules = vec!();
     for rule in ErrorLoggerIterator(parse_rule_list(block.into_iter())) {
         match rule {
-            QualifiedRule_(rule) => parse_style_rule(rule, &mut rules, namespaces, base_url),
-            AtRule_(rule) => parse_nested_at_rule(
-                rule.name.as_slice().to_ascii_lower().as_slice(), rule, &mut rules, namespaces, base_url),
+            QualifiedRule_(rule) => {
+                stylesheets::parse_style_rule(context, rule, &mut rules, namespaces, base_url)
+            }
+            AtRule_(rule) => {
+                stylesheets::parse_nested_at_rule(context,
+                                                  rule.name.as_slice().to_ascii_lower().as_slice(),
+                                                  rule,
+                                                  &mut rules,
+                                                  namespaces,
+                                                  base_url)
+            }
         }
     }
     parent_rules.push(CSSMediaRule(MediaRule {
diff --git a/components/style/node.rs b/components/style/node.rs
index 5a765f2798d..a1c9a8071c4 100644
--- a/components/style/node.rs
+++ b/components/style/node.rs
@@ -5,7 +5,8 @@
 //! Traits that nodes must implement. Breaks the otherwise-cyclic dependency between layout and
 //! style.
 
-use legacy::{IntegerAttribute, LengthAttribute};
+use cssparser::RGBA;
+use legacy::{IntegerAttribute, LengthAttribute, SimpleColorAttribute, UnsignedIntegerAttribute};
 use selectors::AttrSelector;
 use servo_util::str::LengthOrPercentageOrAuto;
 use string_cache::{Atom, Namespace};
@@ -47,6 +48,7 @@ pub trait TElement<'a> : Copy {
     fn get_enabled_state(self) -> bool;
     fn get_checked_state(self) -> bool;
     fn has_class(self, name: &Atom) -> bool;
+    fn has_nonzero_border(self) -> bool;
 
     // Ordinarily I wouldn't use callbacks like this, but the alternative is
     // really messy, since there is a `JSRef` and a `RefCell` involved. Maybe
@@ -58,4 +60,6 @@ pub trait TElement<'a> : Copy {
 pub trait TElementAttributes : Copy {
     fn get_length_attribute(self, attribute: LengthAttribute) -> LengthOrPercentageOrAuto;
     fn get_integer_attribute(self, attribute: IntegerAttribute) -> Option<i32>;
+    fn get_unsigned_integer_attribute(self, attribute: UnsignedIntegerAttribute) -> Option<u32>;
+    fn get_simple_color_attribute(self, attribute: SimpleColorAttribute) -> Option<RGBA>;
 }
diff --git a/components/style/selector_matching.rs b/components/style/selector_matching.rs
index 7cd1fd1d232..5482745721f 100644
--- a/components/style/selector_matching.rs
+++ b/components/style/selector_matching.rs
@@ -11,21 +11,31 @@ use sync::Arc;
 use url::Url;
 
 use servo_util::bloom::BloomFilter;
-use servo_util::geometry::Au;
 use servo_util::resource_files::read_resource_file;
 use servo_util::smallvec::VecLike;
 use servo_util::sort;
-use servo_util::str::{AutoLpa, LengthLpa, PercentageLpa};
 use string_cache::Atom;
 
-use legacy::{SizeIntegerAttribute, WidthLengthAttribute};
+use legacy::PresentationalHintSynthesis;
 use media_queries::Device;
 use node::{TElement, TElementAttributes, TNode};
-use properties::{PropertyDeclaration, PropertyDeclarationBlock, SpecifiedValue, WidthDeclaration};
-use properties::{specified};
-use selectors::*;
+use properties::{PropertyDeclaration, PropertyDeclarationBlock};
+use selectors::{After, AnyLink, AttrDashMatch, AttrEqual};
+use selectors::{AttrExists, AttrIncludes, AttrPrefixMatch};
+use selectors::{AttrSubstringMatch, AttrSuffixMatch, Before, CaseInsensitive, CaseSensitive};
+use selectors::{Checked, Child, ClassSelector};
+use selectors::{CompoundSelector, Descendant, Disabled, Enabled, FirstChild, FirstOfType};
+use selectors::{Hover, IDSelector, LastChild, LastOfType};
+use selectors::{LaterSibling, LocalName, LocalNameSelector};
+use selectors::{NamespaceSelector, Link, Negation};
+use selectors::{NextSibling, NthChild};
+use selectors::{NthLastChild, NthLastOfType};
+use selectors::{NthOfType, OnlyChild, OnlyOfType, PseudoElement, Root};
+use selectors::{SelectorList, ServoNonzeroBorder, SimpleSelector, Visited};
+use selectors::{get_selector_list_selectors};
 use stylesheets::{Stylesheet, iter_stylesheet_media_rules, iter_stylesheet_style_rules};
 
+#[deriving(Clone, PartialEq)]
 pub enum StylesheetOrigin {
     UserAgentOrigin,
     AuthorOrigin,
@@ -295,7 +305,6 @@ impl Stylist {
             after_map: PerPseudoElementSelectorMap::new(),
             rules_source_order: 0u,
         };
-        // FIXME: Add quirks-mode.css in quirks mode.
         // FIXME: Add iso-8859-9.css when the document’s encoding is ISO-8859-8.
         // FIXME: presentational-hints.css should be at author origin with zero specificity.
         //        (Does it make a difference?)
@@ -391,6 +400,15 @@ impl Stylist {
         self.is_dirty |= is_dirty;
     }
 
+    pub fn add_quirks_mode_stylesheet(&mut self) {
+        self.add_stylesheet(Stylesheet::from_bytes(
+            read_resource_file(["quirks-mode.css"]).unwrap().as_slice(),
+            Url::parse("chrome:///quirks-mode.css").unwrap(),
+            None,
+            None,
+            UserAgentOrigin))
+    }
+
     pub fn add_stylesheet(&mut self, stylesheet: Stylesheet) {
         self.stylesheets.push(stylesheet);
         self.is_dirty = true;
@@ -477,62 +495,6 @@ impl Stylist {
 
         shareable
     }
-
-    /// Synthesizes rules from various HTML attributes (mostly legacy junk from HTML4) that confer
-    /// *presentational hints* as defined in the HTML5 specification. This handles stuff like
-    /// `<body bgcolor>`, `<input size>`, `<td width>`, and so forth.
-    fn synthesize_presentational_hints_for_legacy_attributes<'a,E,N,V>(
-                                                             &self,
-                                                             node: &N,
-                                                             matching_rules_list: &mut V,
-                                                             shareable: &mut bool)
-                                                             where E: TElement<'a> +
-                                                                      TElementAttributes,
-                                                                   N: TNode<'a,E>,
-                                                                   V: VecLike<DeclarationBlock> {
-        let element = node.as_element();
-        match element.get_local_name() {
-            name if *name == atom!("td") => {
-                match element.get_length_attribute(WidthLengthAttribute) {
-                    AutoLpa => {}
-                    PercentageLpa(percentage) => {
-                        let width_value = specified::LPA_Percentage(percentage);
-                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
-                                WidthDeclaration(SpecifiedValue(width_value))));
-                        *shareable = false
-                    }
-                    LengthLpa(length) => {
-                        let width_value = specified::LPA_Length(specified::Au_(length));
-                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
-                                WidthDeclaration(SpecifiedValue(width_value))));
-                        *shareable = false
-                    }
-                };
-            }
-            name if *name == atom!("input") => {
-                match element.get_integer_attribute(SizeIntegerAttribute) {
-                    Some(value) if value != 0 => {
-                        // Per HTML 4.01 § 17.4, this value is in characters if `type` is `text` or
-                        // `password` and in pixels otherwise.
-                        //
-                        // FIXME(pcwalton): More use of atoms, please!
-                        let value = match element.get_attr(&ns!(""), &atom!("type")) {
-                            Some("text") | Some("password") => {
-                                specified::ServoCharacterWidth(value)
-                            }
-                            _ => specified::Au_(Au::from_px(value as int)),
-                        };
-                        matching_rules_list.vec_push(DeclarationBlock::from_declaration(
-                                WidthDeclaration(SpecifiedValue(specified::LPA_Length(
-                                            value)))));
-                        *shareable = false
-                    }
-                    Some(_) | None => {}
-                }
-            }
-            _ => {}
-        }
-    }
 }
 
 struct PerOriginSelectorMap {
@@ -858,6 +820,13 @@ pub fn common_style_affecting_attributes() -> [CommonStyleAffectingAttributeInfo
     ]
 }
 
+/// Attributes that, if present, disable style sharing. All legacy HTML attributes must be in
+/// either this list or `common_style_affecting_attributes`. See the comment in
+/// `synthesize_presentational_hints_for_legacy_attributes`.
+pub fn rare_style_affecting_attributes() -> [Atom, ..3] {
+    [ atom!("bgcolor"), atom!("border"), atom!("colspan") ]
+}
+
 /// Determines whether the given element matches the given single selector.
 ///
 /// NB: If you add support for any new kinds of selectors to this routine, be sure to set
@@ -1052,6 +1021,12 @@ pub fn matches_simple_selector<'a,E,N>(selector: &SimpleSelector,
                 matches_generic_nth_child(element, 0, 1, true, true)
         }
 
+        ServoNonzeroBorder => {
+            *shareable = false;
+            let elem = element.as_element();
+            elem.has_nonzero_border()
+        }
+
         Negation(ref negated) => {
             *shareable = false;
             !negated.iter().all(|s| matches_simple_selector(s, element, shareable))
@@ -1204,12 +1179,16 @@ mod tests {
     /// Each sublist of the result contains the Rules for one StyleRule.
     fn get_mock_rules(css_selectors: &[&str]) -> Vec<Vec<Rule>> {
         use namespaces::NamespaceMap;
-        use selectors::parse_selector_list;
+        use selectors::{ParserContext, parse_selector_list};
+        use selector_matching::AuthorOrigin;
         use cssparser::tokenize;
 
         let namespaces = NamespaceMap::new();
         css_selectors.iter().enumerate().map(|(i, selectors)| {
-            parse_selector_list(tokenize(*selectors).map(|(c, _)| c), &namespaces)
+            let context = ParserContext {
+                origin: AuthorOrigin,
+            };
+            parse_selector_list(&context, tokenize(*selectors).map(|(c, _)| c), &namespaces)
             .unwrap().into_iter().map(|s| {
                 Rule {
                     selector: s.compound_selectors.clone(),
diff --git a/components/style/selectors.rs b/components/style/selectors.rs
index da0e2b7b638..1d72a530383 100644
--- a/components/style/selectors.rs
+++ b/components/style/selectors.rs
@@ -9,10 +9,16 @@ use sync::Arc;
 use cssparser::ast::*;
 use cssparser::{tokenize, parse_nth};
 
+use selector_matching::{StylesheetOrigin, UserAgentOrigin};
 use string_cache::{Atom, Namespace};
 
 use namespaces::NamespaceMap;
 
+/// Ambient data used by the parser.
+pub struct ParserContext {
+    /// The origin of this stylesheet.
+    pub origin: StylesheetOrigin,
+}
 
 #[deriving(PartialEq, Clone)]
 pub struct Selector {
@@ -79,7 +85,8 @@ pub enum SimpleSelector {
     NthLastOfType(i32, i32),
     FirstOfType,
     LastOfType,
-    OnlyOfType
+    OnlyOfType,
+    ServoNonzeroBorder,
     // ...
 }
 
@@ -111,12 +118,6 @@ pub enum NamespaceConstraint {
 }
 
 
-pub fn parse_selector_list_from_str(input: &str) -> Result<SelectorList, ()> {
-    let namespaces = NamespaceMap::new();
-    let iter = tokenize(input).map(|(token, _)| token);
-    parse_selector_list(iter, &namespaces).map(|s| SelectorList { selectors: s })
-}
-
 /// Re-exported to script, but opaque.
 pub struct SelectorList {
     selectors: Vec<Selector>
@@ -127,70 +128,9 @@ pub fn get_selector_list_selectors<'a>(selector_list: &'a SelectorList) -> &'a [
     selector_list.selectors.as_slice()
 }
 
-/// Parse a comma-separated list of Selectors.
-/// aka Selector Group in http://www.w3.org/TR/css3-selectors/#grouping
-///
-/// Return the Selectors or None if there is an invalid selector.
-pub fn parse_selector_list<I: Iterator<ComponentValue>>(
-                           iter: I, namespaces: &NamespaceMap)
-                           -> Result<Vec<Selector>, ()> {
-    let iter = &mut iter.peekable();
-    let mut results = vec![try!(parse_selector(iter, namespaces))];
-
-    loop {
-        skip_whitespace(iter);
-        match iter.peek() {
-            None => break,  // EOF
-            Some(&Comma) => {
-                iter.next();
-            }
-            _ => return Err(()),
-        }
-        results.push(try!(parse_selector(iter, namespaces)));
-    }
-    Ok(results)
-}
-
 
 type Iter<I> = iter::Peekable<ComponentValue, I>;
 
-/// Build up a Selector.
-/// selector : simple_selector_sequence [ combinator simple_selector_sequence ]* ;
-///
-/// `Err` means invalid selector.
-fn parse_selector<I: Iterator<ComponentValue>>(
-                  iter: &mut Iter<I>, namespaces: &NamespaceMap)
-                  -> Result<Selector, ()> {
-    let (first, mut pseudo_element) = try!(parse_simple_selectors(iter, namespaces));
-    let mut compound = CompoundSelector{ simple_selectors: first, next: None };
-
-    while pseudo_element.is_none() {
-        let any_whitespace = skip_whitespace(iter);
-        let combinator = match iter.peek() {
-            None => break,  // EOF
-            Some(&Comma) => break,
-            Some(&Delim('>')) => { iter.next(); Child },
-            Some(&Delim('+')) => { iter.next(); NextSibling },
-            Some(&Delim('~')) => { iter.next(); LaterSibling },
-            Some(_) => {
-                if any_whitespace { Descendant }
-                else { return Err(()) }
-            }
-        };
-        let (simple_selectors, pseudo) = try!(parse_simple_selectors(iter, namespaces));
-        compound = CompoundSelector {
-            simple_selectors: simple_selectors,
-            next: Some((box compound, combinator))
-        };
-        pseudo_element = pseudo;
-    }
-    Ok(Selector {
-        specificity: compute_specificity(&compound, &pseudo_element),
-        compound_selectors: Arc::new(compound),
-        pseudo_element: pseudo_element,
-    })
-}
-
 
 fn compute_specificity(mut selector: &CompoundSelector,
                        pseudo_element: &Option<PseudoElement>) -> u32 {
@@ -231,7 +171,7 @@ fn compute_specificity(mut selector: &CompoundSelector,
 //                | &Empty | &Lang(*)
                 | &NthChild(..) | &NthLastChild(..)
                 | &NthOfType(..) | &NthLastOfType(..)
-                | &FirstOfType | &LastOfType | &OnlyOfType
+                | &FirstOfType | &LastOfType | &OnlyOfType | &ServoNonzeroBorder
                 => specificity.class_like_selectors += 1,
                 &NamespaceSelector(..) => (),
                 &Negation(ref negated)
@@ -247,32 +187,6 @@ fn compute_specificity(mut selector: &CompoundSelector,
 }
 
 
-/// simple_selector_sequence
-/// : [ type_selector | universal ] [ HASH | class | attrib | pseudo | negation ]*
-/// | [ HASH | class | attrib | pseudo | negation ]+
-///
-/// `Err(())` means invalid selector
-fn parse_simple_selectors<I: Iterator<ComponentValue>>(
-                          iter: &mut Iter<I>, namespaces: &NamespaceMap)
-                          -> Result<(Vec<SimpleSelector>, Option<PseudoElement>), ()> {
-    let mut empty = true;
-    let mut simple_selectors = match try!(parse_type_selector(iter, namespaces)) {
-        None => vec![],
-        Some(s) => { empty = false; s }
-    };
-
-    let mut pseudo_element = None;
-    loop {
-        match try!(parse_one_simple_selector(iter, namespaces, /* inside_negation = */ false)) {
-            None => break,
-            Some(SimpleSelectorResult(s)) => { simple_selectors.push(s); empty = false },
-            Some(PseudoElementResult(p)) => { pseudo_element = Some(p); empty = false; break },
-        }
-    }
-    if empty { Err(()) }  // An empty selector is invalid
-    else { Ok((simple_selectors, pseudo_element)) }
-}
-
 
 /// * `Err(())`: Invalid selector, abort
 /// * `Ok(None)`: Not a type selector, could be something else. `iter` was not consumed.
@@ -309,67 +223,6 @@ enum SimpleSelectorParseResult {
     PseudoElementResult(PseudoElement),
 }
 
-/// Parse a simple selector other than a type selector.
-///
-/// * `Err(())`: Invalid selector, abort
-/// * `Ok(None)`: Not a simple selector, could be something else. `iter` was not consumed.
-/// * `Ok(Some(_))`: Parsed a simple selector or pseudo-element
-fn parse_one_simple_selector<I: Iterator<ComponentValue>>(
-                             iter: &mut Iter<I>, namespaces: &NamespaceMap, inside_negation: bool)
-                             -> Result<Option<SimpleSelectorParseResult>, ()> {
-    match iter.peek() {
-        Some(&IDHash(_)) => match iter.next() {
-            Some(IDHash(id)) => Ok(Some(SimpleSelectorResult(
-                IDSelector(Atom::from_slice(id.as_slice()))))),
-            _ => panic!("Implementation error, this should not happen."),
-        },
-        Some(&Delim('.')) => {
-            iter.next();
-            match iter.next() {
-                Some(Ident(class)) => Ok(Some(SimpleSelectorResult(
-                    ClassSelector(Atom::from_slice(class.as_slice()))))),
-                _ => Err(()),
-            }
-        }
-        Some(&SquareBracketBlock(_)) => match iter.next() {
-            Some(SquareBracketBlock(content))
-            => Ok(Some(SimpleSelectorResult(try!(parse_attribute_selector(content, namespaces))))),
-            _ => panic!("Implementation error, this should not happen."),
-        },
-        Some(&Colon) => {
-            iter.next();
-            match iter.next() {
-                Some(Ident(name)) => match parse_simple_pseudo_class(name.as_slice()) {
-                    Err(()) => {
-                        match name.as_slice().to_ascii_lower().as_slice() {
-                            // Supported CSS 2.1 pseudo-elements only.
-                            // ** Do not add to this list! **
-                            "before" => Ok(Some(PseudoElementResult(Before))),
-                            "after" => Ok(Some(PseudoElementResult(After))),
-//                            "first-line" => PseudoElementResult(FirstLine),
-//                            "first-letter" => PseudoElementResult(FirstLetter),
-                            _ => Err(())
-                        }
-                    },
-                    Ok(result) => Ok(Some(SimpleSelectorResult(result))),
-                },
-                Some(Function(name, arguments))
-                => Ok(Some(SimpleSelectorResult(try!(parse_functional_pseudo_class(
-                        name, arguments, namespaces, inside_negation))))),
-                Some(Colon) => {
-                    match iter.next() {
-                        Some(Ident(name))
-                        => Ok(Some(PseudoElementResult(try!(parse_pseudo_element(name))))),
-                        _ => Err(()),
-                    }
-                }
-                _ => Err(()),
-            }
-        }
-        _ => Ok(None),
-    }
-}
-
 
 /// * `Err(())`: Invalid selector, abort
 /// * `Ok(None)`: Not a simple selector, could be something else. `iter` was not consumed.
@@ -489,8 +342,224 @@ fn parse_attribute_flags<I: Iterator<ComponentValue>>(iter: &mut Iter<I>)
     }
 }
 
+pub fn parse_selector_list_from_str(context: &ParserContext, input: &str)
+                                    -> Result<SelectorList,()> {
+    let namespaces = NamespaceMap::new();
+    let iter = tokenize(input).map(|(token, _)| token);
+    parse_selector_list(context, iter, &namespaces).map(|s| SelectorList { selectors: s })
+}
+
+/// Parse a comma-separated list of Selectors.
+/// aka Selector Group in http://www.w3.org/TR/css3-selectors/#grouping
+///
+/// Return the Selectors or None if there is an invalid selector.
+pub fn parse_selector_list<I>(context: &ParserContext, iter: I, namespaces: &NamespaceMap)
+                              -> Result<Vec<Selector>,()>
+                              where I: Iterator<ComponentValue> {
+    let iter = &mut iter.peekable();
+    let mut results = vec![try!(parse_selector(context, iter, namespaces))];
 
-fn parse_simple_pseudo_class(name: &str) -> Result<SimpleSelector, ()> {
+    loop {
+        skip_whitespace(iter);
+        match iter.peek() {
+            None => break,  // EOF
+            Some(&Comma) => {
+                iter.next();
+            }
+            _ => return Err(()),
+        }
+        results.push(try!(parse_selector(context, iter, namespaces)));
+    }
+    Ok(results)
+}
+/// Build up a Selector.
+/// selector : simple_selector_sequence [ combinator simple_selector_sequence ]* ;
+///
+/// `Err` means invalid selector.
+fn parse_selector<I>(context: &ParserContext, iter: &mut Iter<I>, namespaces: &NamespaceMap)
+                     -> Result<Selector,()>
+                     where I: Iterator<ComponentValue> {
+    let (first, mut pseudo_element) = try!(parse_simple_selectors(context, iter, namespaces));
+    let mut compound = CompoundSelector{ simple_selectors: first, next: None };
+
+    while pseudo_element.is_none() {
+        let any_whitespace = skip_whitespace(iter);
+        let combinator = match iter.peek() {
+            None => break,  // EOF
+            Some(&Comma) => break,
+            Some(&Delim('>')) => { iter.next(); Child },
+            Some(&Delim('+')) => { iter.next(); NextSibling },
+            Some(&Delim('~')) => { iter.next(); LaterSibling },
+            Some(_) => {
+                if any_whitespace { Descendant }
+                else { return Err(()) }
+            }
+        };
+        let (simple_selectors, pseudo) = try!(parse_simple_selectors(context, iter, namespaces));
+        compound = CompoundSelector {
+            simple_selectors: simple_selectors,
+            next: Some((box compound, combinator))
+        };
+        pseudo_element = pseudo;
+    }
+    Ok(Selector {
+        specificity: compute_specificity(&compound, &pseudo_element),
+        compound_selectors: Arc::new(compound),
+        pseudo_element: pseudo_element,
+    })
+}
+
+/// Level 3: Parse **one** simple_selector
+fn parse_negation(context: &ParserContext,
+                  arguments: Vec<ComponentValue>,
+                  namespaces: &NamespaceMap)
+                  -> Result<SimpleSelector,()> {
+    let iter = &mut arguments.into_iter().peekable();
+    match try!(parse_type_selector(iter, namespaces)) {
+        Some(type_selector) => Ok(Negation(type_selector)),
+        None => {
+            match try!(parse_one_simple_selector(context,
+                                                 iter,
+                                                 namespaces,
+                                                 /* inside_negation = */ true)) {
+                Some(SimpleSelectorResult(simple_selector)) => {
+                    Ok(Negation(vec![simple_selector]))
+                }
+                _ => Err(())
+            }
+        },
+    }
+}
+
+/// simple_selector_sequence
+/// : [ type_selector | universal ] [ HASH | class | attrib | pseudo | negation ]*
+/// | [ HASH | class | attrib | pseudo | negation ]+
+///
+/// `Err(())` means invalid selector
+fn parse_simple_selectors<I>(context: &ParserContext,
+                             iter: &mut Iter<I>,
+                             namespaces: &NamespaceMap)
+                             -> Result<(Vec<SimpleSelector>, Option<PseudoElement>),()>
+                             where I: Iterator<ComponentValue> {
+    let mut empty = true;
+    let mut simple_selectors = match try!(parse_type_selector(iter, namespaces)) {
+        None => vec![],
+        Some(s) => { empty = false; s }
+    };
+
+    let mut pseudo_element = None;
+    loop {
+        match try!(parse_one_simple_selector(context,
+                                             iter,
+                                             namespaces,
+                                             /* inside_negation = */ false)) {
+            None => break,
+            Some(SimpleSelectorResult(s)) => { simple_selectors.push(s); empty = false },
+            Some(PseudoElementResult(p)) => { pseudo_element = Some(p); empty = false; break },
+        }
+    }
+    if empty {
+        // An empty selector is invalid.
+        Err(())
+    } else {
+        Ok((simple_selectors, pseudo_element))
+    }
+}
+
+fn parse_functional_pseudo_class(context: &ParserContext,
+                                 name: String,
+                                 arguments: Vec<ComponentValue>,
+                                 namespaces: &NamespaceMap,
+                                 inside_negation: bool)
+                                 -> Result<SimpleSelector,()> {
+    match name.as_slice().to_ascii_lower().as_slice() {
+//        "lang" => parse_lang(arguments),
+        "nth-child"        => parse_nth(arguments.as_slice()).map(|(a, b)| NthChild(a, b)),
+        "nth-last-child"   => parse_nth(arguments.as_slice()).map(|(a, b)| NthLastChild(a, b)),
+        "nth-of-type"      => parse_nth(arguments.as_slice()).map(|(a, b)| NthOfType(a, b)),
+        "nth-last-of-type" => parse_nth(arguments.as_slice()).map(|(a, b)| NthLastOfType(a, b)),
+        "not" => {
+            if inside_negation {
+                Err(())
+            } else {
+                parse_negation(context, arguments, namespaces)
+            }
+        }
+        _ => Err(())
+    }
+}
+
+/// Parse a simple selector other than a type selector.
+///
+/// * `Err(())`: Invalid selector, abort
+/// * `Ok(None)`: Not a simple selector, could be something else. `iter` was not consumed.
+/// * `Ok(Some(_))`: Parsed a simple selector or pseudo-element
+fn parse_one_simple_selector<I>(context: &ParserContext,
+                                iter: &mut Iter<I>,
+                                namespaces: &NamespaceMap,
+                                inside_negation: bool)
+                                -> Result<Option<SimpleSelectorParseResult>,()>
+                                where I: Iterator<ComponentValue> {
+    match iter.peek() {
+        Some(&IDHash(_)) => match iter.next() {
+            Some(IDHash(id)) => Ok(Some(SimpleSelectorResult(
+                IDSelector(Atom::from_slice(id.as_slice()))))),
+            _ => panic!("Implementation error, this should not happen."),
+        },
+        Some(&Delim('.')) => {
+            iter.next();
+            match iter.next() {
+                Some(Ident(class)) => Ok(Some(SimpleSelectorResult(
+                    ClassSelector(Atom::from_slice(class.as_slice()))))),
+                _ => Err(()),
+            }
+        }
+        Some(&SquareBracketBlock(_)) => match iter.next() {
+            Some(SquareBracketBlock(content))
+            => Ok(Some(SimpleSelectorResult(try!(parse_attribute_selector(content, namespaces))))),
+            _ => panic!("Implementation error, this should not happen."),
+        },
+        Some(&Colon) => {
+            iter.next();
+            match iter.next() {
+                Some(Ident(name)) => match parse_simple_pseudo_class(context, name.as_slice()) {
+                    Err(()) => {
+                        match name.as_slice().to_ascii_lower().as_slice() {
+                            // Supported CSS 2.1 pseudo-elements only.
+                            // ** Do not add to this list! **
+                            "before" => Ok(Some(PseudoElementResult(Before))),
+                            "after" => Ok(Some(PseudoElementResult(After))),
+//                            "first-line" => PseudoElementResult(FirstLine),
+//                            "first-letter" => PseudoElementResult(FirstLetter),
+                            _ => Err(())
+                        }
+                    },
+                    Ok(result) => Ok(Some(SimpleSelectorResult(result))),
+                },
+                Some(Function(name, arguments))
+                => {
+                    Ok(Some(SimpleSelectorResult(try!(parse_functional_pseudo_class(
+                                        context,
+                                        name,
+                                        arguments,
+                                        namespaces,
+                                        inside_negation)))))
+                }
+                Some(Colon) => {
+                    match iter.next() {
+                        Some(Ident(name))
+                        => Ok(Some(PseudoElementResult(try!(parse_pseudo_element(name))))),
+                        _ => Err(()),
+                    }
+                }
+                _ => Err(()),
+            }
+        }
+        _ => Ok(None),
+    }
+}
+
+fn parse_simple_pseudo_class(context: &ParserContext, name: &str) -> Result<SimpleSelector,()> {
     match name.to_ascii_lower().as_slice() {
         "any-link" => Ok(AnyLink),
         "link" => Ok(Link),
@@ -506,27 +575,12 @@ fn parse_simple_pseudo_class(name: &str) -> Result<SimpleSelector, ()> {
         "first-of-type" => Ok(FirstOfType),
         "last-of-type"  => Ok(LastOfType),
         "only-of-type"  => Ok(OnlyOfType),
-//        "empty" => Ok(Empty),
-        _ => Err(())
-    }
-}
-
-
-fn parse_functional_pseudo_class(name: String, arguments: Vec<ComponentValue>,
-                                 namespaces: &NamespaceMap, inside_negation: bool)
-                                 -> Result<SimpleSelector, ()> {
-    match name.as_slice().to_ascii_lower().as_slice() {
-//        "lang" => parse_lang(arguments),
-        "nth-child"        => parse_nth(arguments.as_slice()).map(|(a, b)| NthChild(a, b)),
-        "nth-last-child"   => parse_nth(arguments.as_slice()).map(|(a, b)| NthLastChild(a, b)),
-        "nth-of-type"      => parse_nth(arguments.as_slice()).map(|(a, b)| NthOfType(a, b)),
-        "nth-last-of-type" => parse_nth(arguments.as_slice()).map(|(a, b)| NthLastOfType(a, b)),
-        "not" => if inside_negation { Err(()) } else { parse_negation(arguments, namespaces) },
+        "-servo-nonzero-border" if context.origin == UserAgentOrigin => Ok(ServoNonzeroBorder),
+//      "empty" => Ok(Empty),
         _ => Err(())
     }
 }
 
-
 fn parse_pseudo_element(name: String) -> Result<PseudoElement, ()> {
     match name.as_slice().to_ascii_lower().as_slice() {
         // All supported pseudo-elements
@@ -551,21 +605,6 @@ fn parse_pseudo_element(name: String) -> Result<PseudoElement, ()> {
 //}
 
 
-/// Level 3: Parse **one** simple_selector
-fn parse_negation(arguments: Vec<ComponentValue>, namespaces: &NamespaceMap)
-                  -> Result<SimpleSelector, ()> {
-    let iter = &mut arguments.into_iter().peekable();
-    match try!(parse_type_selector(iter, namespaces)) {
-        Some(type_selector) => Ok(Negation(type_selector)),
-        None => {
-            match try!(parse_one_simple_selector(iter, namespaces, /* inside_negation = */ true)) {
-                Some(SimpleSelectorResult(simple_selector)) => Ok(Negation(vec![simple_selector])),
-                _ => Err(())
-            }
-        },
-    }
-}
-
 
 /// Assuming the next token is an ident, consume it and return its value
 #[inline]
@@ -593,6 +632,7 @@ mod tests {
     use sync::Arc;
     use cssparser;
     use namespaces::NamespaceMap;
+    use selector_matching::AuthorOrigin;
     use string_cache::Atom;
     use super::*;
 
@@ -601,7 +641,10 @@ mod tests {
     }
 
     fn parse_ns(input: &str, namespaces: &NamespaceMap) -> Result<Vec<Selector>, ()> {
-        parse_selector_list(cssparser::tokenize(input).map(|(v, _)| v), namespaces)
+        let context = ParserContext {
+            origin: AuthorOrigin,
+        };
+        parse_selector_list(&context, cssparser::tokenize(input).map(|(v, _)| v), namespaces)
     }
 
     fn specificity(a: u32, b: u32, c: u32) -> u32 {
diff --git a/components/style/stylesheets.rs b/components/style/stylesheets.rs
index efec013ee2d..824172af037 100644
--- a/components/style/stylesheets.rs
+++ b/components/style/stylesheets.rs
@@ -10,12 +10,11 @@ use encoding::EncodingRef;
 
 use cssparser::{decode_stylesheet_bytes, tokenize, parse_stylesheet_rules, ToCss};
 use cssparser::ast::*;
-use selectors;
+use selectors::{mod, ParserContext};
 use properties;
 use errors::{ErrorLoggerIterator, log_css_error};
 use namespaces::{NamespaceMap, parse_namespace_rule};
-use media_queries::{Device, MediaRule, parse_media_rule};
-use media_queries;
+use media_queries::{mod, Device, MediaRule};
 use font_face::{FontFaceRule, Source, parse_font_face_rule, iter_font_face_rules_inner};
 use selector_matching::StylesheetOrigin;
 
@@ -53,9 +52,12 @@ impl Stylesheet {
         Stylesheet::from_bytes(bytes.as_slice(), base_url, protocol_encoding_label, environment_encoding, origin)
     }
 
-    pub fn from_bytes(
-            bytes: &[u8], base_url: Url, protocol_encoding_label: Option<&str>,
-            environment_encoding: Option<EncodingRef>, origin: StylesheetOrigin) -> Stylesheet {
+    pub fn from_bytes(bytes: &[u8],
+                      base_url: Url,
+                      protocol_encoding_label: Option<&str>,
+                      environment_encoding: Option<EncodingRef>,
+                      origin: StylesheetOrigin)
+                      -> Stylesheet {
         // TODO: bytes.as_slice could be bytes.container_as_bytes()
         let (string, _) = decode_stylesheet_bytes(
             bytes.as_slice(), protocol_encoding_label, environment_encoding);
@@ -67,6 +69,11 @@ impl Stylesheet {
         static STATE_IMPORTS: uint = 2;
         static STATE_NAMESPACES: uint = 3;
         static STATE_BODY: uint = 4;
+
+        let parser_context = ParserContext {
+            origin: origin,
+        };
+
         let mut state: uint = STATE_CHARSET;
 
         let mut rules = vec!();
@@ -77,7 +84,7 @@ impl Stylesheet {
             match rule {
                 QualifiedRule_(rule) => {
                     next_state = STATE_BODY;
-                    parse_style_rule(rule, &mut rules, &namespaces, &base_url)
+                    parse_style_rule(&parser_context, rule, &mut rules, &namespaces, &base_url)
                 },
                 AtRule_(rule) => {
                     let lower_name = rule.name.as_slice().to_ascii_lower();
@@ -114,7 +121,12 @@ impl Stylesheet {
                         },
                         _ => {
                             next_state = STATE_BODY;
-                            parse_nested_at_rule(lower_name.as_slice(), rule, &mut rules, &namespaces, &base_url)
+                            parse_nested_at_rule(&parser_context,
+                                                 lower_name.as_slice(),
+                                                 rule,
+                                                 &mut rules,
+                                                 &namespaces,
+                                                 &base_url)
                         },
                     }
                 },
@@ -128,13 +140,36 @@ impl Stylesheet {
     }
 }
 
+// lower_name is passed explicitly to avoid computing it twice.
+pub fn parse_nested_at_rule(context: &ParserContext,
+                            lower_name: &str,
+                            rule: AtRule,
+                            parent_rules: &mut Vec<CSSRule>,
+                            namespaces: &NamespaceMap,
+                            base_url: &Url) {
+    match lower_name {
+        "media" => {
+            media_queries::parse_media_rule(context, rule, parent_rules, namespaces, base_url)
+        }
+        "font-face" => parse_font_face_rule(rule, parent_rules, base_url),
+        _ => log_css_error(rule.location,
+                           format!("Unsupported at-rule: @{:s}", lower_name).as_slice())
+    }
+}
 
-pub fn parse_style_rule(rule: QualifiedRule, parent_rules: &mut Vec<CSSRule>,
-                        namespaces: &NamespaceMap, base_url: &Url) {
-    let QualifiedRule { location, prelude, block} = rule;
+pub fn parse_style_rule(context: &ParserContext,
+                        rule: QualifiedRule,
+                        parent_rules: &mut Vec<CSSRule>,
+                        namespaces: &NamespaceMap,
+                        base_url: &Url) {
+    let QualifiedRule {
+        location,
+        prelude,
+        block
+    } = rule;
     // FIXME: avoid doing this for valid selectors
     let serialized = prelude.iter().to_css();
-    match selectors::parse_selector_list(prelude.into_iter(), namespaces) {
+    match selectors::parse_selector_list(context, prelude.into_iter(), namespaces) {
         Ok(selectors) => parent_rules.push(CSSStyleRule(StyleRule{
             selectors: selectors,
             declarations: properties::parse_property_declaration_list(block.into_iter(), base_url)
@@ -144,19 +179,6 @@ pub fn parse_style_rule(rule: QualifiedRule, parent_rules: &mut Vec<CSSRule>,
     }
 }
 
-
-// lower_name is passed explicitly to avoid computing it twice.
-pub fn parse_nested_at_rule(lower_name: &str, rule: AtRule,
-                            parent_rules: &mut Vec<CSSRule>, namespaces: &NamespaceMap, base_url: &Url) {
-    match lower_name {
-        "media" => parse_media_rule(rule, parent_rules, namespaces, base_url),
-        "font-face" => parse_font_face_rule(rule, parent_rules, base_url),
-        _ => log_css_error(rule.location,
-                           format!("Unsupported at-rule: @{:s}", lower_name).as_slice())
-    }
-}
-
-
 pub fn iter_style_rules<'a>(rules: &[CSSRule], device: &media_queries::Device,
                             callback: |&StyleRule|) {
     for rule in rules.iter() {
diff --git a/components/util/Cargo.toml b/components/util/Cargo.toml
index 29fc71d25a5..331fd2fb840 100644
--- a/components/util/Cargo.toml
+++ b/components/util/Cargo.toml
@@ -7,6 +7,9 @@ authors = ["The Servo Project Developers"]
 name = "util"
 path = "lib.rs"
 
+[dependencies.cssparser]
+git = "https://github.com/servo/rust-cssparser"
+
 [dependencies.geom]
 git = "https://github.com/servo/rust-geom"
 
diff --git a/components/util/lib.rs b/components/util/lib.rs
index f556dda6eb9..b0e4cff8c62 100644
--- a/components/util/lib.rs
+++ b/components/util/lib.rs
@@ -13,6 +13,7 @@ extern crate log;
 
 extern crate alloc;
 extern crate collections;
+extern crate cssparser;
 extern crate geom;
 extern crate getopts;
 extern crate layers;
diff --git a/components/util/str.rs b/components/util/str.rs
index 28aedee4f30..7b2cfdf5107 100644
--- a/components/util/str.rs
+++ b/components/util/str.rs
@@ -4,6 +4,8 @@
 
 use geometry::Au;
 
+use cssparser::{mod, RGBA, RGBAColor};
+use std::ascii::AsciiExt;
 use std::from_str::FromStr;
 use std::iter::Filter;
 use std::str::{CharEq, CharSplits};
@@ -61,7 +63,8 @@ pub static HTML_SPACE_CHARACTERS: StaticCharVec = &[
     '\u000d',
 ];
 
-pub fn split_html_space_chars<'a>(s: &'a str) -> Filter<'a, &'a str, CharSplits<'a, StaticCharVec>> {
+pub fn split_html_space_chars<'a>(s: &'a str)
+                                  -> Filter<'a, &'a str, CharSplits<'a, StaticCharVec>> {
     s.split(HTML_SPACE_CHARACTERS).filter(|&split| !split.is_empty())
 }
 
@@ -76,7 +79,6 @@ fn do_parse_integer<T: Iterator<char>>(input: T) -> Option<i64> {
         }
     }
 
-
     let mut input = input.skip_while(|c| {
         HTML_SPACE_CHARACTERS.iter().any(|s| s == c)
     }).peekable();
@@ -184,6 +186,137 @@ pub fn parse_length(mut value: &str) -> LengthOrPercentageOrAuto {
     }
 }
 
+/// Parses a legacy color per HTML5 § 2.4.6. If unparseable, `Err` is returned.
+pub fn parse_legacy_color(mut input: &str) -> Result<RGBA,()> {
+    // Steps 1 and 2.
+    if input.len() == 0 {
+        return Err(())
+    }
+
+    // Step 3.
+    input = input.trim_left_chars(Whitespace).trim_right_chars(Whitespace);
+
+    // Step 4.
+    if input.eq_ignore_ascii_case("transparent") {
+        return Err(())
+    }
+
+    // Step 5.
+    match cssparser::parse_color_keyword(input) {
+        Ok(RGBAColor(rgba)) => return Ok(rgba),
+        _ => {}
+    }
+
+    // Step 6.
+    if input.len() == 4 {
+        match (input.as_bytes()[0],
+               hex(input.as_bytes()[1] as char),
+               hex(input.as_bytes()[2] as char),
+               hex(input.as_bytes()[3] as char)) {
+            (b'#', Ok(r), Ok(g), Ok(b)) => {
+                return Ok(RGBA {
+                    red: (r as f32) * 17.0 / 255.0,
+                    green: (g as f32) * 17.0 / 255.0,
+                    blue: (b as f32) * 17.0 / 255.0,
+                    alpha: 1.0,
+                })
+            }
+            _ => {}
+        }
+    }
+
+    // Step 7.
+    let mut new_input = String::new();
+    for ch in input.chars() {
+        if ch as u32 > 0xffff {
+            new_input.push_str("00")
+        } else {
+            new_input.push(ch)
+        }
+    }
+    let mut input = new_input.as_slice();
+
+    // Step 8.
+    for (char_count, (index, _)) in input.char_indices().enumerate() {
+        if char_count == 128 {
+            input = input.slice_to(index);
+            break
+        }
+    }
+
+    // Step 9.
+    if input.char_at(0) == '#' {
+        input = input.slice_from(1)
+    }
+
+    // Step 10.
+    let mut new_input = Vec::new();
+    for ch in input.chars() {
+        if hex(ch).is_ok() {
+            new_input.push(ch as u8)
+        } else {
+            new_input.push(b'0')
+        }
+    }
+    let mut input = new_input;
+
+    // Step 11.
+    while input.len() == 0 || (input.len() % 3) != 0 {
+        input.push(b'0')
+    }
+
+    // Step 12.
+    let mut length = input.len() / 3;
+    let (mut red, mut green, mut blue) = (input.slice_to(length),
+                                          input.slice(length, length * 2),
+                                          input.slice_from(length * 2));
+
+    // Step 13.
+    if length > 8 {
+        red = red.slice_from(length - 8);
+        green = green.slice_from(length - 8);
+        blue = blue.slice_from(length - 8);
+        length = 8
+    }
+
+    // Step 14.
+    while length > 2 && red[0] == b'0' && green[0] == b'0' && blue[0] == b'0' {
+        red = red.slice_from(1);
+        green = green.slice_from(1);
+        blue = blue.slice_from(1);
+        length -= 1
+    }
+
+    // Steps 15-20.
+    return Ok(RGBA {
+        red: hex_string(red).unwrap() as f32 / 255.0,
+        green: hex_string(green).unwrap() as f32 / 255.0,
+        blue: hex_string(blue).unwrap() as f32 / 255.0,
+        alpha: 1.0,
+    });
+
+    fn hex(ch: char) -> Result<u8,()> {
+        match ch {
+            '0'...'9' => Ok((ch as u8) - b'0'),
+            'a'...'f' => Ok((ch as u8) - b'a' + 10),
+            'A'...'F' => Ok((ch as u8) - b'A' + 10),
+            _ => Err(()),
+        }
+    }
+
+    fn hex_string(string: &[u8]) -> Result<u8,()> {
+        match string.len() {
+            0 => Err(()),
+            1 => hex(string[0] as char),
+            _ => {
+                let upper = try!(hex(string[0] as char));
+                let lower = try!(hex(string[1] as char));
+                Ok((upper << 4) | lower)
+            }
+        }
+    }
+}
+
 
 #[deriving(Clone, Eq, PartialEq, Hash, Show)]
 pub struct LowercaseString {