layout: Move text decoration propagation to stacking context tree construction (#37069)

Text decorations have a special kind of propagation. Instead of
propating these during box tree construction, move propagation to
stacking context tree construction. This will allow for using a very
easy type of incremental layout when text decorations change. For
instance, when a link changes color during hovering over it, we can skip
all of box and fragment tree construction.

In addition, propagation works a bit better now and color and style
properly move down from their originating `Fragment`s.

This introduces three new failures, because now we are drawing the
text-decoration with the correct color in more places, which exposes an
issue we have with text-decorations not being drawn in relation to the
baseline (taking into account `vertical-align`).

Testing: There are tests for these changes.
Fixes #31736.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>

components/layout/construct_modern.rs

@@ -150,7 +150,6 @@ impl<'a, 'dom> ModernContainerBuilder<'a, 'dom> {
 
                     let inline_formatting_context = inline_formatting_context_builder.finish(
                         self.context,
-                        self.propagated_data,
                         true,  /* has_first_formatted_line */
                         false, /* is_single_line_text_box */
                         self.info.style.writing_mode.to_bidi_level(),

components/layout/display_list/mod.rs

@@ -572,6 +572,7 @@ impl Fragment {
         section: StackingContextSection,
         is_hit_test_for_scrollable_overflow: bool,
         is_collapsed_table_borders: bool,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let spatial_id = builder.spatial_id(builder.current_scroll_node_id);
         let clip_chain_id = builder.clip_chain_id(builder.current_clip_id);
@@ -683,9 +684,12 @@ impl Fragment {
                     .get_inherited_box()
                     .visibility
                 {
-                    Visibility::Visible => {
+                    Visibility::Visible => self.build_display_list_for_text_fragment(
-                        self.build_display_list_for_text_fragment(text, builder, containing_block)
+                        text,
-                    },
+                        builder,
+                        containing_block,
+                        text_decorations,
+                    ),
                     Visibility::Hidden => (),
                     Visibility::Collapse => (),
                 }
@@ -723,6 +727,7 @@ impl Fragment {
         fragment: &TextFragment,
         builder: &mut DisplayListBuilder,
         containing_block: &PhysicalRect<Au>,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         // NB: The order of painting text components (CSS Text Decoration Module Level 3) is:
         // shadows, underline, overline, text, text-emphasis, and then line-through.
@@ -774,23 +779,33 @@ impl Fragment {
             );
         }
 
-        if fragment
+        for text_decoration in text_decorations.iter() {
-            .text_decoration_line
+            if text_decoration.line.contains(TextDecorationLine::UNDERLINE) {
-            .contains(TextDecorationLine::UNDERLINE)
-        {
                 let mut rect = rect;
                 rect.origin.y += font_metrics.ascent - font_metrics.underline_offset;
-            rect.size.height = Au::from_f32_px(font_metrics.underline_size.to_nearest_pixel(dppx));
+                rect.size.height =
-            self.build_display_list_for_text_decoration(&parent_style, builder, &rect, &color);
+                    Au::from_f32_px(font_metrics.underline_size.to_nearest_pixel(dppx));
+                self.build_display_list_for_text_decoration(
+                    &parent_style,
+                    builder,
+                    &rect,
+                    text_decoration,
+                );
+            }
         }
 
-        if fragment
+        for text_decoration in text_decorations.iter() {
-            .text_decoration_line
+            if text_decoration.line.contains(TextDecorationLine::OVERLINE) {
-            .contains(TextDecorationLine::OVERLINE)
-        {
                 let mut rect = rect;
-            rect.size.height = Au::from_f32_px(font_metrics.underline_size.to_nearest_pixel(dppx));
+                rect.size.height =
-            self.build_display_list_for_text_decoration(&parent_style, builder, &rect, &color);
+                    Au::from_f32_px(font_metrics.underline_size.to_nearest_pixel(dppx));
+                self.build_display_list_for_text_decoration(
+                    &parent_style,
+                    builder,
+                    &rect,
+                    text_decoration,
+                );
+            }
         }
 
         // TODO: This caret/text selection implementation currently does not account for vertical text
@@ -867,14 +882,22 @@ impl Fragment {
             None,
         );
 
-        if fragment
+        for text_decoration in text_decorations.iter() {
-            .text_decoration_line
+            if text_decoration
+                .line
                 .contains(TextDecorationLine::LINE_THROUGH)
             {
                 let mut rect = rect;
                 rect.origin.y += font_metrics.ascent - font_metrics.strikeout_offset;
-            rect.size.height = Au::from_f32_px(font_metrics.strikeout_size.to_nearest_pixel(dppx));
+                rect.size.height =
-            self.build_display_list_for_text_decoration(&parent_style, builder, &rect, &color);
+                    Au::from_f32_px(font_metrics.strikeout_size.to_nearest_pixel(dppx));
+                self.build_display_list_for_text_decoration(
+                    &parent_style,
+                    builder,
+                    &rect,
+                    text_decoration,
+                );
+            }
         }
 
         if !shadows.0.is_empty() {
@@ -887,15 +910,11 @@ impl Fragment {
         parent_style: &ServoArc<ComputedValues>,
         builder: &mut DisplayListBuilder,
         rect: &PhysicalRect<Au>,
-        color: &AbsoluteColor,
+        text_decoration: &FragmentTextDecoration,
     ) {
         let rect = rect.to_webrender();
         let wavy_line_thickness = (0.33 * rect.size().height).ceil();
-        let text_decoration_color = parent_style
+        if text_decoration.style == ComputedTextDecorationStyle::MozNone {
-            .clone_text_decoration_color()
-            .resolve_to_absolute(color);
-        let text_decoration_style = parent_style.clone_text_decoration_style();
-        if text_decoration_style == ComputedTextDecorationStyle::MozNone {
             return;
         }
         let common_properties = builder.common_properties(rect, parent_style);
@@ -904,8 +923,8 @@ impl Fragment {
             &rect,
             wavy_line_thickness,
             wr::LineOrientation::Horizontal,
-            &rgba(text_decoration_color),
+            &rgba(text_decoration.color),
-            text_decoration_style.to_webrender(),
+            text_decoration.style.to_webrender(),
         );
         // XXX(ferjm) support text-decoration-style: double
     }

components/layout/display_list/stacking_context.rs

@@ -5,6 +5,7 @@
 use core::f32;
 use std::cell::RefCell;
 use std::mem;
+use std::sync::Arc;
 
 use app_units::Au;
 use base::id::ScrollTreeNodeId;
@@ -18,13 +19,15 @@ use euclid::default::{Point2D, Rect, Size2D};
 use log::warn;
 use servo_config::opts::DebugOptions;
 use style::Zero;
+use style::color::AbsoluteColor;
 use style::computed_values::float::T as ComputedFloat;
 use style::computed_values::mix_blend_mode::T as ComputedMixBlendMode;
 use style::computed_values::overflow_x::T as ComputedOverflow;
 use style::computed_values::position::T as ComputedPosition;
+use style::computed_values::text_decoration_style::T as TextDecorationStyle;
 use style::values::computed::angle::Angle;
 use style::values::computed::basic_shape::ClipPath;
-use style::values::computed::{ClipRectOrAuto, Length};
+use style::values::computed::{ClipRectOrAuto, Length, TextDecorationLine};
 use style::values::generics::box_::Perspective;
 use style::values::generics::transform::{self, GenericRotate, GenericScale, GenericTranslate};
 use style::values::specified::box_::DisplayOutside;
@@ -168,12 +171,14 @@ impl StackingContextTree {
         };
 
         let mut root_stacking_context = StackingContext::create_root(root_scroll_node_id, debug);
+        let text_decorations = Default::default();
         for fragment in &fragment_tree.root_fragments {
             fragment.build_stacking_context_tree(
                 &mut stacking_context_tree,
                 &containing_block_info,
                 &mut root_stacking_context,
                 StackingContextBuildMode::SkipHoisted,
+                &text_decorations,
             );
         }
         root_stacking_context.sort();
@@ -246,6 +251,14 @@ impl StackingContextTree {
     }
 }
 
+/// The text decorations for a Fragment, collecting during [`StackingContextTree`] construction.
+#[derive(Clone, Debug)]
+pub(crate) struct FragmentTextDecoration {
+    pub line: TextDecorationLine,
+    pub color: AbsoluteColor,
+    pub style: TextDecorationStyle,
+}
+
 /// A piece of content that directly belongs to a section of a stacking context.
 ///
 /// This is generally part of a fragment, like its borders or foreground, but it
@@ -261,6 +274,7 @@ pub(crate) enum StackingContextContent {
         fragment: Fragment,
         is_hit_test_for_scrollable_overflow: bool,
         is_collapsed_table_borders: bool,
+        text_decorations: Arc<Vec<FragmentTextDecoration>>,
     },
 
     /// An index into [StackingContext::atomic_inline_stacking_containers].
@@ -292,6 +306,7 @@ impl StackingContextContent {
                 fragment,
                 is_hit_test_for_scrollable_overflow,
                 is_collapsed_table_borders,
+                text_decorations,
             } => {
                 builder.current_scroll_node_id = *scroll_node_id;
                 builder.current_reference_frame_scroll_node_id = *reference_frame_scroll_node_id;
@@ -302,6 +317,7 @@ impl StackingContextContent {
                     *section,
                     *is_hit_test_for_scrollable_overflow,
                     *is_collapsed_table_borders,
+                    text_decorations,
                 );
             },
             Self::AtomicInlineStackingContainer { index } => {
@@ -800,6 +816,7 @@ impl Fragment {
         containing_block_info: &ContainingBlockInfo,
         stacking_context: &mut StackingContext,
         mode: StackingContextBuildMode,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let containing_block = containing_block_info.get_containing_block_for_fragment(self);
         let fragment_clone = self.clone();
@@ -812,6 +829,11 @@ impl Fragment {
                     return;
                 }
 
+                let text_decorations = match self {
+                    Fragment::Float(..) => &Default::default(),
+                    _ => text_decorations,
+                };
+
                 // If this fragment has a transform applied that makes it take up no space
                 // then we don't need to create any stacking contexts for it.
                 let has_non_invertible_transform = fragment
@@ -828,6 +850,7 @@ impl Fragment {
                     containing_block,
                     containing_block_info,
                     stacking_context,
+                    text_decorations,
                 );
             },
             Fragment::AbsoluteOrFixedPositioned(fragment) => {
@@ -842,6 +865,7 @@ impl Fragment {
                     containing_block_info,
                     stacking_context,
                     StackingContextBuildMode::IncludeHoisted,
+                    &Default::default(),
                 );
             },
             Fragment::Positioning(fragment) => {
@@ -851,6 +875,7 @@ impl Fragment {
                     containing_block,
                     containing_block_info,
                     stacking_context,
+                    text_decorations,
                 );
             },
             Fragment::Text(_) | Fragment::Image(_) | Fragment::IFrame(_) => {
@@ -867,6 +892,7 @@ impl Fragment {
                         fragment: fragment_clone,
                         is_hit_test_for_scrollable_overflow: false,
                         is_collapsed_table_borders: false,
+                        text_decorations: text_decorations.clone(),
                     });
             },
         }
@@ -929,6 +955,7 @@ impl BoxFragment {
         containing_block: &ContainingBlock,
         containing_block_info: &ContainingBlockInfo,
         parent_stacking_context: &mut StackingContext,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         self.build_stacking_context_tree_maybe_creating_reference_frame(
             fragment,
@@ -936,6 +963,7 @@ impl BoxFragment {
             containing_block,
             containing_block_info,
             parent_stacking_context,
+            text_decorations,
         );
     }
 
@@ -946,6 +974,7 @@ impl BoxFragment {
         containing_block: &ContainingBlock,
         containing_block_info: &ContainingBlockInfo,
         parent_stacking_context: &mut StackingContext,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let reference_frame_data =
             match self.reference_frame_data_if_necessary(&containing_block.rect) {
@@ -957,6 +986,7 @@ impl BoxFragment {
                         containing_block,
                         containing_block_info,
                         parent_stacking_context,
+                        text_decorations,
                     );
                 },
             };
@@ -999,6 +1029,7 @@ impl BoxFragment {
             &adjusted_containing_block,
             &new_containing_block_info,
             parent_stacking_context,
+            text_decorations,
         );
     }
 
@@ -1009,6 +1040,7 @@ impl BoxFragment {
         containing_block: &ContainingBlock,
         containing_block_info: &ContainingBlockInfo,
         parent_stacking_context: &mut StackingContext,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let context_type = match self.get_stacking_context_type() {
             Some(context_type) => context_type,
@@ -1019,6 +1051,7 @@ impl BoxFragment {
                     containing_block,
                     containing_block_info,
                     parent_stacking_context,
+                    text_decorations,
                 );
                 return;
             },
@@ -1072,6 +1105,7 @@ impl BoxFragment {
             containing_block,
             containing_block_info,
             &mut child_stacking_context,
+            text_decorations,
         );
 
         let mut stolen_children = vec![];
@@ -1097,6 +1131,7 @@ impl BoxFragment {
         containing_block: &ContainingBlock,
         containing_block_info: &ContainingBlockInfo,
         stacking_context: &mut StackingContext,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let mut new_scroll_node_id = containing_block.scroll_node_id;
         let mut new_clip_id = containing_block.clip_id;
@@ -1164,6 +1199,7 @@ impl BoxFragment {
                     fragment: fragment.clone(),
                     is_hit_test_for_scrollable_overflow: false,
                     is_collapsed_table_borders: false,
+                    text_decorations: text_decorations.clone(),
                 });
         };
 
@@ -1198,6 +1234,7 @@ impl BoxFragment {
                         fragment: fragment.clone(),
                         is_hit_test_for_scrollable_overflow: true,
                         is_collapsed_table_borders: false,
+                        text_decorations: text_decorations.clone(),
                     });
             }
         }
@@ -1239,12 +1276,46 @@ impl BoxFragment {
             containing_block_info.new_for_non_absolute_descendants(&for_non_absolute_descendants)
         };
 
+        // Text decorations are not propagated to atomic inline-level descendants.
+        // From https://drafts.csswg.org/css2/#lining-striking-props:
+        // > Note that text decorations are not propagated to floating and absolutely
+        // > positioned descendants, nor to the contents of atomic inline-level descendants
+        // > such as inline blocks and inline tables.
+        let text_decorations = match self.is_atomic_inline_level() ||
+            self.base
+                .flags
+                .contains(FragmentFlags::IS_OUTSIDE_LIST_ITEM_MARKER)
+        {
+            true => &Default::default(),
+            false => text_decorations,
+        };
+
+        let new_text_decoration;
+        let text_decorations = match self.style.clone_text_decoration_line() {
+            TextDecorationLine::NONE => text_decorations,
+            line => {
+                let mut new_vector = (**text_decorations).clone();
+                let color = &self.style.get_inherited_text().color;
+                new_vector.push(FragmentTextDecoration {
+                    line,
+                    color: self
+                        .style
+                        .clone_text_decoration_color()
+                        .resolve_to_absolute(color),
+                    style: self.style.clone_text_decoration_style(),
+                });
+                new_text_decoration = Arc::new(new_vector);
+                &new_text_decoration
+            },
+        };
+
         for child in &self.children {
             child.build_stacking_context_tree(
                 stacking_context_tree,
                 &new_containing_block_info,
                 stacking_context,
                 StackingContextBuildMode::SkipHoisted,
+                text_decorations,
             );
         }
 
@@ -1263,6 +1334,7 @@ impl BoxFragment {
                     fragment: fragment.clone(),
                     is_hit_test_for_scrollable_overflow: false,
                     is_collapsed_table_borders: true,
+                    text_decorations: text_decorations.clone(),
                 });
         }
     }
@@ -1646,6 +1718,7 @@ impl PositioningFragment {
         containing_block: &ContainingBlock,
         containing_block_info: &ContainingBlockInfo,
         stacking_context: &mut StackingContext,
+        text_decorations: &Arc<Vec<FragmentTextDecoration>>,
     ) {
         let rect = self
             .rect
@@ -1660,6 +1733,7 @@ impl PositioningFragment {
                 &new_containing_block_info,
                 stacking_context,
                 StackingContextBuildMode::SkipHoisted,
+                text_decorations,
             );
         }
     }

components/layout/flexbox/mod.rs

@@ -105,8 +105,7 @@ impl FlexContainer {
         contents: NonReplacedContents,
         propagated_data: PropagatedBoxTreeData,
     ) -> Self {
-        let mut builder =
+        let mut builder = ModernContainerBuilder::new(context, info, propagated_data);
-            ModernContainerBuilder::new(context, info, propagated_data.union(&info.style));
         contents.traverse(context, info, &mut builder);
         let items = builder.finish();
 

components/layout/flow/construct.rs

@@ -199,7 +199,7 @@ impl<'dom, 'style> BlockContainerBuilder<'dom, 'style> {
             context,
             info,
             block_level_boxes: Vec::new(),
-            propagated_data: propagated_data.union(&info.style),
+            propagated_data,
             have_already_seen_first_line_for_text_indent: false,
             anonymous_box_info: None,
             anonymous_table_content: Vec::new(),
@@ -228,7 +228,6 @@ impl<'dom, 'style> BlockContainerBuilder<'dom, 'style> {
     fn finish_ongoing_inline_formatting_context(&mut self) -> Option<InlineFormattingContext> {
         self.inline_formatting_context_builder.take()?.finish(
             self.context,
-            self.propagated_data,
             !self.have_already_seen_first_line_for_text_indent,
             self.info.is_single_line_text_input(),
             self.info.style.writing_mode.to_bidi_level(),
@@ -280,16 +279,6 @@ impl<'dom, 'style> BlockContainerBuilder<'dom, 'style> {
         // creation of an inline table. It requires the parent to be an inline box.
         let inline_table = self.currently_processing_inline_box();
 
-        // Text decorations are not propagated to atomic inline-level descendants.
-        // From https://drafts.csswg.org/css2/#lining-striking-props:
-        // >  Note that text decorations are not propagated to floating and absolutely
-        // > positioned descendants, nor to the contents of atomic inline-level descendants
-        // > such as inline blocks and inline tables.
-        let propagated_data = match inline_table {
-            true => self.propagated_data.without_text_decorations(),
-            false => self.propagated_data,
-        };
-
         let contents: Vec<AnonymousTableContent<'dom>> =
             self.anonymous_table_content.drain(..).collect();
         let last_text = match contents.last() {
@@ -298,7 +287,7 @@ impl<'dom, 'style> BlockContainerBuilder<'dom, 'style> {
         };
 
         let (table_info, ifc) =
-            Table::construct_anonymous(self.context, self.info, contents, propagated_data);
+            Table::construct_anonymous(self.context, self.info, contents, self.propagated_data);
 
         if inline_table {
             self.ensure_inline_formatting_context_builder()
@@ -315,7 +304,7 @@ impl<'dom, 'style> BlockContainerBuilder<'dom, 'style> {
                 info: table_info,
                 box_slot: BoxSlot::dummy(),
                 kind: BlockLevelCreator::AnonymousTable { table_block },
-                propagated_data,
+                propagated_data: self.propagated_data,
             });
         }
 
@@ -464,7 +453,7 @@ impl<'dom> BlockContainerBuilder<'dom, '_> {
                 contents,
                 list_item_style,
             },
-            propagated_data: self.propagated_data.without_text_decorations(),
+            propagated_data: self.propagated_data,
         });
     }
 
@@ -480,15 +469,14 @@ impl<'dom> BlockContainerBuilder<'dom, '_> {
         else {
             // If this inline element is an atomic, handle it and return.
             let context = self.context;
-            let propagaged_data = self.propagated_data.without_text_decorations();
+            let propagated_data = self.propagated_data;
             let atomic = self.ensure_inline_formatting_context_builder().push_atomic(
                 IndependentFormattingContext::construct(
                     context,
                     info,
                     display_inside,
                     contents,
-                    // Text decorations are not propagated to atomic inline-level descendants.
+                    propagated_data,
-                    propagaged_data,
                 ),
             );
             box_slot.set(LayoutBox::InlineLevel(vec![atomic]));
@@ -550,7 +538,6 @@ impl<'dom> BlockContainerBuilder<'dom, '_> {
             .and_then(|builder| {
                 builder.split_around_block_and_finish(
                     self.context,
-                    self.propagated_data,
                     !self.have_already_seen_first_line_for_text_indent,
                     self.info.style.writing_mode.to_bidi_level(),
                 )
@@ -631,7 +618,7 @@ impl<'dom> BlockContainerBuilder<'dom, '_> {
             info: info.clone(),
             box_slot,
             kind,
-            propagated_data: self.propagated_data.without_text_decorations(),
+            propagated_data: self.propagated_data,
         });
     }
 
@@ -664,7 +651,7 @@ impl<'dom> BlockContainerBuilder<'dom, '_> {
             info: info.clone(),
             box_slot,
             kind,
-            propagated_data: self.propagated_data.without_text_decorations(),
+            propagated_data: self.propagated_data,
         });
     }
 
@@ -754,7 +741,7 @@ impl BlockLevelJob<'_> {
                     context,
                     info,
                     contents,
-                    self.propagated_data.without_text_decorations(),
+                    self.propagated_data,
                     false, /* is_list_item */
                 );
                 ArcRefCell::new(BlockLevelBox::OutsideMarker(OutsideMarker {

components/layout/flow/float.rs

@@ -897,8 +897,7 @@ impl FloatBox {
                 info,
                 display_inside,
                 contents,
-                // Text decorations are not propagated to any out-of-flow descendants
+                propagated_data,
-                propagated_data.without_text_decorations(),
             ),
         }
     }

components/layout/flow/inline/construct.rs

@@ -16,7 +16,6 @@ use super::{
     InlineBox, InlineBoxIdentifier, InlineBoxes, InlineFormattingContext, InlineItem,
     SharedInlineStyles,
 };
-use crate::PropagatedBoxTreeData;
 use crate::cell::ArcRefCell;
 use crate::context::LayoutContext;
 use crate::dom_traversal::NodeAndStyleInfo;
@@ -344,7 +343,6 @@ impl InlineFormattingContextBuilder {
     pub(crate) fn split_around_block_and_finish(
         &mut self,
         layout_context: &LayoutContext,
-        propagated_data: PropagatedBoxTreeData,
         has_first_formatted_line: bool,
         default_bidi_level: Level,
     ) -> Option<InlineFormattingContext> {
@@ -386,7 +384,6 @@ impl InlineFormattingContextBuilder {
 
         inline_builder_from_before_split.finish(
             layout_context,
-            propagated_data,
             has_first_formatted_line,
             /* is_single_line_text_input = */ false,
             default_bidi_level,
@@ -397,7 +394,6 @@ impl InlineFormattingContextBuilder {
     pub(crate) fn finish(
         self,
         layout_context: &LayoutContext,
-        propagated_data: PropagatedBoxTreeData,
         has_first_formatted_line: bool,
         is_single_line_text_input: bool,
         default_bidi_level: Level,
@@ -410,7 +406,6 @@ impl InlineFormattingContextBuilder {
         Some(InlineFormattingContext::new_with_builder(
             self,
             layout_context,
-            propagated_data,
             has_first_formatted_line,
             is_single_line_text_input,
             default_bidi_level,

components/layout/flow/inline/inline_box.rs

@@ -256,13 +256,7 @@ impl InlineBoxContainerState {
         }
 
         Self {
-            base: InlineContainerState::new(
+            base: InlineContainerState::new(style, flags, Some(parent_container), font_metrics),
-                style,
-                flags,
-                Some(parent_container),
-                parent_container.text_decoration_line,
-                font_metrics,
-            ),
             identifier: inline_box.identifier,
             base_fragment_info: inline_box.base.base_fragment_info,
             pbm,

components/layout/flow/inline/line.rs

@@ -15,7 +15,6 @@ use style::values::generics::box_::{GenericVerticalAlign, VerticalAlignKeyword};
 use style::values::generics::font::LineHeight;
 use style::values::specified::align::AlignFlags;
 use style::values::specified::box_::DisplayOutside;
-use style::values::specified::text::TextDecorationLine;
 use unicode_bidi::{BidiInfo, Level};
 use webrender_api::FontInstanceKey;
 
@@ -572,7 +571,6 @@ impl LineItemLayout<'_, '_> {
                 font_metrics: text_item.font_metrics,
                 font_key: text_item.font_key,
                 glyphs: text_item.text,
-                text_decoration_line: text_item.text_decoration_line,
                 justification_adjustment: self.justification_adjustment,
                 selection_range: text_item.selection_range,
             })),
@@ -765,7 +763,6 @@ pub(super) struct TextRunLineItem {
     pub text: Vec<std::sync::Arc<GlyphStore>>,
     pub font_metrics: FontMetrics,
     pub font_key: FontInstanceKey,
-    pub text_decoration_line: TextDecorationLine,
     /// The BiDi level of this [`TextRunLineItem`] to enable reordering.
     pub bidi_level: Level,
     pub selection_range: Option<Range<ByteIndex>>,

components/layout/flow/inline/mod.rs

@@ -103,7 +103,7 @@ use style::properties::style_structs::InheritedText;
 use style::values::generics::box_::VerticalAlignKeyword;
 use style::values::generics::font::LineHeight;
 use style::values::specified::box_::BaselineSource;
-use style::values::specified::text::{TextAlignKeyword, TextDecorationLine};
+use style::values::specified::text::TextAlignKeyword;
 use style::values::specified::{TextAlignLast, TextJustify};
 use text_run::{
     TextRun, XI_LINE_BREAKING_CLASS_GL, XI_LINE_BREAKING_CLASS_WJ, XI_LINE_BREAKING_CLASS_ZWJ,
@@ -134,7 +134,7 @@ use crate::geom::{LogicalRect, LogicalVec2, ToLogical};
 use crate::positioned::{AbsolutelyPositionedBox, PositioningContext};
 use crate::sizing::{ComputeInlineContentSizes, ContentSizes, InlineContentSizesResult};
 use crate::style_ext::{ComputedValuesExt, PaddingBorderMargin};
-use crate::{ConstraintSpace, ContainingBlock, PropagatedBoxTreeData, SharedStyle};
+use crate::{ConstraintSpace, ContainingBlock, SharedStyle};
 
 // From gfxFontConstants.h in Firefox.
 static FONT_SUBSCRIPT_OFFSET_RATIO: f32 = 0.20;
@@ -163,8 +163,6 @@ pub(crate) struct InlineFormattingContext {
     /// share styles with all [`TextRun`] children.
     pub(super) shared_inline_styles: SharedInlineStyles,
 
-    pub(super) text_decoration_line: TextDecorationLine,
-
     /// Whether this IFC contains the 1st formatted line of an element:
     /// <https://www.w3.org/TR/css-pseudo-4/#first-formatted-line>.
     pub(super) has_first_formatted_line: bool,
@@ -628,12 +626,6 @@ pub(super) struct InlineContainerState {
     /// this inline box on the current line OR any previous line.
     has_content: RefCell<bool>,
 
-    /// Indicates whether this nesting level have text decorations in effect.
-    /// From <https://drafts.csswg.org/css-text-decor/#line-decoration>
-    // "When specified on or propagated to a block container that establishes
-    //  an IFC..."
-    text_decoration_line: TextDecorationLine,
-
     /// The block size contribution of this container's default font ie the size of the
     /// "strut." Whether this is integrated into the [`Self::nested_strut_block_sizes`]
     /// depends on the line-height quirk described in
@@ -1461,7 +1453,6 @@ impl InlineFormattingContextLayout<'_> {
                 inline_styles: text_run.inline_styles.clone(),
                 font_metrics,
                 font_key: ifc_font_info.key,
-                text_decoration_line: self.current_inline_container_state().text_decoration_line,
                 bidi_level,
                 selection_range,
             },
@@ -1655,7 +1646,6 @@ impl InlineFormattingContext {
     pub(super) fn new_with_builder(
         builder: InlineFormattingContextBuilder,
         layout_context: &LayoutContext,
-        propagated_data: PropagatedBoxTreeData,
         has_first_formatted_line: bool,
         is_single_line_text_input: bool,
         starting_bidi_level: Level,
@@ -1711,7 +1701,6 @@ impl InlineFormattingContext {
                 .last()
                 .expect("Should have at least one SharedInlineStyle for the root of an IFC")
                 .clone(),
-            text_decoration_line: propagated_data.text_decoration,
             has_first_formatted_line,
             contains_floats: builder.contains_floats,
             is_single_line_text_input,
@@ -1781,7 +1770,6 @@ impl InlineFormattingContext {
                 style.to_arc(),
                 inline_container_state_flags,
                 None, /* parent_container */
-                self.text_decoration_line,
                 default_font_metrics.as_ref(),
             ),
             inline_box_state_stack: Vec::new(),
@@ -1879,10 +1867,8 @@ impl InlineContainerState {
         style: Arc<ComputedValues>,
         flags: InlineContainerStateFlags,
         parent_container: Option<&InlineContainerState>,
-        parent_text_decoration_line: TextDecorationLine,
         font_metrics: Option<&FontMetrics>,
     ) -> Self {
-        let text_decoration_line = parent_text_decoration_line | style.clone_text_decoration_line();
         let font_metrics = font_metrics.cloned().unwrap_or_else(FontMetrics::empty);
         let line_height = line_height(
             &style,
@@ -1919,7 +1905,6 @@ impl InlineContainerState {
             style,
             flags,
             has_content: RefCell::new(false),
-            text_decoration_line,
             nested_strut_block_sizes: nested_block_sizes,
             strut_block_sizes,
             baseline_offset,

components/layout/flow/root.rs

@@ -314,7 +314,7 @@ fn construct_for_root_element(
     let contents = ReplacedContents::for_element(root_element, context)
         .map_or_else(|| NonReplacedContents::OfElement.into(), Contents::Replaced);
 
-    let propagated_data = PropagatedBoxTreeData::default().union(&info.style);
+    let propagated_data = PropagatedBoxTreeData::default();
     let root_box = if box_style.position.is_absolutely_positioned() {
         BlockLevelBox::OutOfFlowAbsolutelyPositionedBox(ArcRefCell::new(
             AbsolutelyPositionedBox::construct(context, &info, display_inside, contents),

components/layout/fragment_tree/fragment.rs

@@ -14,7 +14,6 @@ use range::Range as ServoRange;
 use servo_arc::Arc as ServoArc;
 use style::Zero;
 use style::properties::ComputedValues;
-use style::values::specified::text::TextDecorationLine;
 use webrender_api::{FontInstanceKey, ImageKey};
 
 use super::{
@@ -72,9 +71,6 @@ pub(crate) struct TextFragment {
     #[conditional_malloc_size_of]
     pub glyphs: Vec<Arc<GlyphStore>>,
 
-    /// A flag that represents the _used_ value of the text-decoration property.
-    pub text_decoration_line: TextDecorationLine,
-
     /// Extra space to add for each justification opportunity.
     pub justification_adjustment: Au,
     pub selection_range: Option<ServoRange<ByteIndex>>,

components/layout/lib.rs

@@ -41,7 +41,6 @@ use malloc_size_of_derive::MallocSizeOf;
 use servo_arc::Arc as ServoArc;
 use style::logical_geometry::WritingMode;
 use style::properties::ComputedValues;
-use style::values::computed::TextDecorationLine;
 
 use crate::geom::{LogicalVec2, SizeConstraint};
 use crate::style_ext::AspectRatio;
@@ -163,39 +162,20 @@ impl<'a> From<&'_ DefiniteContainingBlock<'a>> for ContainingBlock<'a> {
 /// propoagation, but only during `BoxTree` construction.
 #[derive(Clone, Copy, Debug)]
 struct PropagatedBoxTreeData {
-    text_decoration: TextDecorationLine,
     allow_percentage_column_in_tables: bool,
 }
 
 impl Default for PropagatedBoxTreeData {
     fn default() -> Self {
         Self {
-            text_decoration: Default::default(),
             allow_percentage_column_in_tables: true,
         }
     }
 }
 
 impl PropagatedBoxTreeData {
-    pub(crate) fn union(&self, style: &ComputedValues) -> Self {
-        Self {
-            // FIXME(#31736): This is only taking into account the line style and not the decoration
-            // color. This should collect information about both so that they can be rendered properly.
-            text_decoration: self.text_decoration | style.clone_text_decoration_line(),
-            allow_percentage_column_in_tables: self.allow_percentage_column_in_tables,
-        }
-    }
-
-    pub(crate) fn without_text_decorations(&self) -> Self {
-        Self {
-            text_decoration: TextDecorationLine::NONE,
-            allow_percentage_column_in_tables: self.allow_percentage_column_in_tables,
-        }
-    }
-
     fn disallowing_percentage_table_columns(&self) -> PropagatedBoxTreeData {
         Self {
-            text_decoration: self.text_decoration,
             allow_percentage_column_in_tables: false,
         }
     }

components/layout/table/construct.rs

@@ -81,12 +81,7 @@ impl Table {
         contents: NonReplacedContents,
         propagated_data: PropagatedBoxTreeData,
     ) -> Self {
-        let mut traversal = TableBuilderTraversal::new(
+        let mut traversal = TableBuilderTraversal::new(context, info, grid_style, propagated_data);
-            context,
-            info,
-            grid_style,
-            propagated_data.union(&info.style),
-        );
         contents.traverse(context, info, &mut traversal);
         traversal.finish()
     }
@@ -771,9 +766,6 @@ impl<'dom> TraversalHandler<'dom> for TableBuilderTraversal<'_, 'dom> {
                     });
                     self.builder.table.row_groups.push(row_group.clone());
 
-                    let previous_propagated_data = self.current_propagated_data;
-                    self.current_propagated_data = self.current_propagated_data.union(&info.style);
-
                     let new_row_group_index = self.builder.table.row_groups.len() - 1;
                     self.current_row_group_index = Some(new_row_group_index);
 
@@ -785,7 +777,6 @@ impl<'dom> TraversalHandler<'dom> for TableBuilderTraversal<'_, 'dom> {
                     self.finish_anonymous_row_if_needed();
 
                     self.current_row_group_index = None;
-                    self.current_propagated_data = previous_propagated_data;
                     self.builder.incoming_rowspans.clear();
 
                     box_slot.set(LayoutBox::TableLevelBox(TableLevelBox::TrackGroup(
@@ -936,7 +927,7 @@ impl<'style, 'builder, 'dom, 'a> TableRowBuilder<'style, 'builder, 'dom, 'a> {
             table_traversal,
             info,
             current_anonymous_cell_content: Vec::new(),
-            propagated_data: propagated_data.union(&info.style),
+            propagated_data,
         }
     }
 

components/layout/taffy/mod.rs

@@ -36,8 +36,7 @@ impl TaffyContainer {
         contents: NonReplacedContents,
         propagated_data: PropagatedBoxTreeData,
     ) -> Self {
-        let mut builder =
+        let mut builder = ModernContainerBuilder::new(context, info, propagated_data);
-            ModernContainerBuilder::new(context, info, propagated_data.union(&info.style));
         contents.traverse(context, info, &mut builder);
         let items = builder.finish();
 

tests/wpt/meta/css/CSS2/generated-content/content-070.xht.ini

@@ -1,2 +0,0 @@
-[content-070.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/text/text-decoration-va-length-001.xht.ini

@@ -0,0 +1,2 @@
+[text-decoration-va-length-001.xht]
+  expected: FAIL

tests/wpt/meta/css/CSS2/text/text-decoration-va-length-002.xht.ini

@@ -0,0 +1,2 @@
+[text-decoration-va-length-002.xht]
+  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-decorating-box-001.html.ini

@@ -0,0 +1,2 @@
+[text-decoration-decorating-box-001.html]
+  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-dotted-002.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-dotted-002.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-propagation-display-contents.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-propagation-display-contents.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-style-multiple.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-style-multiple.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-shadow/decorations-multiple-zorder.html.ini

@@ -1,2 +0,0 @@
-[decorations-multiple-zorder.html]
-  expected: FAIL