clippy: Fix warnings in `components/layout_2020` (#31611)

* clippy: fix warnings in components/layout_2020

* fix: review comments

17 files changed, 59 insertions, 69 deletions

diff --git a/components/layout_2020/display_list/stacking_context.rs b/components/layout_2020/display_list/stacking_context.rs
index 47819d0bd10..68be4cc312b 100644
--- a/components/layout_2020/display_list/stacking_context.rs
+++ b/components/layout_2020/display_list/stacking_context.rs
@@ -430,11 +430,11 @@ impl StackingContext {
         debug_assert!(self
             .real_stacking_contexts_and_positioned_stacking_containers
             .iter()
-            .all(|c| match c.context_type {
+            .all(|c| matches!(
+                c.context_type,
                 StackingContextType::RealStackingContext |
-                StackingContextType::PositionedStackingContainer => true,
-                _ => false,
-            }));
+                    StackingContextType::PositionedStackingContainer
+            )));
         debug_assert!(self
             .float_stacking_containers
             .iter()
diff --git a/components/layout_2020/flexbox/layout.rs b/components/layout_2020/flexbox/layout.rs
index c379dc451fc..5041c707709 100644
--- a/components/layout_2020/flexbox/layout.rs
+++ b/components/layout_2020/flexbox/layout.rs
@@ -1109,7 +1109,7 @@ impl<'a> FlexItem<'a> {
                             flex_context.layout_context,
                             &mut positioning_context,
                             &item_as_containing_block,
-                            &flex_context.containing_block,
+                            flex_context.containing_block,
                         );
 
                         let hypothetical_cross_size = self
diff --git a/components/layout_2020/flow/construct.rs b/components/layout_2020/flow/construct.rs
index cd2dfffc4d0..78ac76d2c6a 100644
--- a/components/layout_2020/flow/construct.rs
+++ b/components/layout_2020/flow/construct.rs
@@ -54,7 +54,7 @@ impl BlockFormattingContext {
         }
     }
 
-    pub fn construct_for_text_runs<'dom>(
+    pub fn construct_for_text_runs(
         runs: impl Iterator<Item = TextRun>,
         layout_context: &LayoutContext,
         text_decoration_line: TextDecorationLine,
@@ -409,15 +409,11 @@ where
         // collecting all Cow strings into a vector and passing them along to text breaking
         // and shaping during final InlineFormattingContext construction.
         let inlines = self.current_inline_level_boxes();
-        match inlines.last_mut().map(|last| last.borrow_mut()) {
-            Some(mut last_box) => match *last_box {
-                InlineLevelBox::TextRun(ref mut text_run) => {
-                    text_run.text.push_str(&input);
-                    return;
-                },
-                _ => {},
-            },
-            _ => {},
+        if let Some(mut last_box) = inlines.last_mut().map(|last| last.borrow_mut()) {
+            if let InlineLevelBox::TextRun(ref mut text_run) = *last_box {
+                text_run.text.push_str(&input);
+                return;
+            }
         }
 
         inlines.push(ArcRefCell::new(InlineLevelBox::TextRun(TextRun::new(
diff --git a/components/layout_2020/flow/float.rs b/components/layout_2020/flow/float.rs
index fa40ae1bb22..739b3503a67 100644
--- a/components/layout_2020/flow/float.rs
+++ b/components/layout_2020/flow/float.rs
@@ -951,7 +951,7 @@ impl FloatBox {
                             layout_context,
                             positioning_context,
                             &containing_block_for_children,
-                            &containing_block,
+                            containing_block,
                         );
                         content_size = LogicalVec2 {
                             inline: inline_size,
diff --git a/components/layout_2020/flow/inline.rs b/components/layout_2020/flow/inline.rs
index 6bf88502d4a..c30e01c59da 100644
--- a/components/layout_2020/flow/inline.rs
+++ b/components/layout_2020/flow/inline.rs
@@ -1384,14 +1384,11 @@ impl<'a, 'b> InlineFormattingContextState<'a, 'b> {
         // Place all floats in this unbreakable segment.
         let mut segment_items = mem::take(&mut self.current_line_segment.line_items);
         for item in segment_items.iter_mut() {
-            match item {
-                LineItem::Float(float_item) => {
-                    self.place_float_line_item_for_commit_to_line(
-                        float_item,
-                        line_inline_size_without_trailing_whitespace,
-                    );
-                },
-                _ => {},
+            if let LineItem::Float(float_item) = item {
+                self.place_float_line_item_for_commit_to_line(
+                    float_item,
+                    line_inline_size_without_trailing_whitespace,
+                );
             }
         }
 
@@ -1450,7 +1447,7 @@ impl InlineFormattingContext {
         }
     }
 
-    fn foreach<'a>(&self, mut func: impl FnMut(InlineFormattingContextIterItem)) {
+    fn foreach(&self, mut func: impl FnMut(InlineFormattingContextIterItem)) {
         // TODO(mrobinson): Using OwnedRef here we could maybe avoid the second borrow when
         // iterating through members of each inline box.
         struct InlineFormattingContextChildBoxIter {
@@ -2006,7 +2003,7 @@ impl IndependentFormattingContext {
                     layout_context,
                     child_positioning_context.as_mut().unwrap(),
                     &containing_block_for_children,
-                    &ifc.containing_block,
+                    ifc.containing_block,
                 );
                 let (inline_size, block_size) =
                     match independent_layout.content_inline_size_for_table {
@@ -2134,15 +2131,12 @@ impl FloatBox {
     }
 }
 
-fn place_pending_floats(ifc: &mut InlineFormattingContextState, line_items: &mut Vec<LineItem>) {
+fn place_pending_floats(ifc: &mut InlineFormattingContextState, line_items: &mut [LineItem]) {
     for item in line_items.iter_mut() {
-        match item {
-            LineItem::Float(float_line_item) => {
-                if float_line_item.needs_placement {
-                    ifc.place_float_fragment(&mut float_line_item.fragment);
-                }
-            },
-            _ => {},
+        if let LineItem::Float(float_line_item) = item {
+            if float_line_item.needs_placement {
+                ifc.place_float_fragment(&mut float_line_item.fragment);
+            }
         }
     }
 }
@@ -2157,11 +2151,11 @@ fn line_height(parent_style: &ComputedValues, font_metrics: &FontMetrics) -> Len
 }
 
 fn is_baseline_relative(vertical_align: GenericVerticalAlign<LengthPercentage>) -> bool {
-    match vertical_align {
+    !matches!(
+        vertical_align,
         GenericVerticalAlign::Keyword(VerticalAlignKeyword::Top) |
-        GenericVerticalAlign::Keyword(VerticalAlignKeyword::Bottom) => false,
-        _ => true,
-    }
+            GenericVerticalAlign::Keyword(VerticalAlignKeyword::Bottom)
+    )
 }
 
 /// Whether or not a strut should be created for an inline container. Normally
diff --git a/components/layout_2020/flow/line.rs b/components/layout_2020/flow/line.rs
index dce1d304fa9..1e2317b70d3 100644
--- a/components/layout_2020/flow/line.rs
+++ b/components/layout_2020/flow/line.rs
@@ -587,11 +587,11 @@ impl FloatLineItem {
 }
 
 fn is_baseline_relative(vertical_align: GenericVerticalAlign<LengthPercentage>) -> bool {
-    match vertical_align {
+    !matches!(
+        vertical_align,
         GenericVerticalAlign::Keyword(VerticalAlignKeyword::Top) |
-        GenericVerticalAlign::Keyword(VerticalAlignKeyword::Bottom) => false,
-        _ => true,
-    }
+            GenericVerticalAlign::Keyword(VerticalAlignKeyword::Bottom)
+    )
 }
 
 fn line_height(parent_style: &ComputedValues, font_metrics: &FontMetrics) -> Length {
diff --git a/components/layout_2020/flow/mod.rs b/components/layout_2020/flow/mod.rs
index d118f040c00..4ebaf01946d 100644
--- a/components/layout_2020/flow/mod.rs
+++ b/components/layout_2020/flow/mod.rs
@@ -613,6 +613,7 @@ impl BlockLevelBox {
 ///
 /// - <https://drafts.csswg.org/css2/visudet.html#blockwidth>
 /// - <https://drafts.csswg.org/css2/visudet.html#normal-block>
+#[allow(clippy::too_many_arguments)]
 fn layout_in_flow_non_replaced_block_level_same_formatting_context(
     layout_context: &LayoutContext,
     positioning_context: &mut PositioningContext,
@@ -856,7 +857,7 @@ impl NonReplacedFormattingContext {
             layout_context,
             positioning_context,
             &containing_block_for_children,
-            &containing_block,
+            containing_block,
         );
 
         let (block_size, inline_size) = match layout.content_inline_size_for_table {
@@ -1162,7 +1163,7 @@ impl NonReplacedFormattingContext {
 /// <https://drafts.csswg.org/css2/visudet.html#block-replaced-width>
 /// <https://drafts.csswg.org/css2/visudet.html#inline-replaced-width>
 /// <https://drafts.csswg.org/css2/visudet.html#inline-replaced-height>
-fn layout_in_flow_replaced_block_level<'a>(
+fn layout_in_flow_replaced_block_level(
     containing_block: &ContainingBlock,
     base_fragment_info: BaseFragmentInfo,
     style: &Arc<ComputedValues>,
@@ -1348,8 +1349,8 @@ fn solve_margins(
     inline_size: Length,
 ) -> ResolvedMargins {
     let (inline_margins, effective_margin_inline_start) =
-        solve_inline_margins_for_in_flow_block_level(containing_block, &pbm, inline_size);
-    let block_margins = solve_block_margins_for_in_flow_block_level(&pbm);
+        solve_inline_margins_for_in_flow_block_level(containing_block, pbm, inline_size);
+    let block_margins = solve_block_margins_for_in_flow_block_level(pbm);
     ResolvedMargins {
         margin: LogicalSides {
             inline_start: inline_margins.0,
diff --git a/components/layout_2020/flow/root.rs b/components/layout_2020/flow/root.rs
index cd2ab4dfe8a..b41d7b6b999 100644
--- a/components/layout_2020/flow/root.rs
+++ b/components/layout_2020/flow/root.rs
@@ -83,6 +83,7 @@ impl BoxTree {
     where
         Node: 'dom + Copy + LayoutNode<'dom> + Send + Sync,
     {
+        #[allow(clippy::enum_variant_names)]
         enum UpdatePoint {
             AbsolutelyPositionedBlockLevelBox(ArcRefCell<BlockLevelBox>),
             AbsolutelyPositionedInlineLevelBox(ArcRefCell<InlineLevelBox>),
diff --git a/components/layout_2020/flow/text_run.rs b/components/layout_2020/flow/text_run.rs
index 7b7dc3d42a7..2667c474d9e 100644
--- a/components/layout_2020/flow/text_run.rs
+++ b/components/layout_2020/flow/text_run.rs
@@ -709,7 +709,7 @@ pub struct TextTransformation<InputIterator> {
     pending_case_conversion_result: Option<PendingCaseConversionResult>,
 }
 
-impl<'a, InputIterator> TextTransformation<InputIterator> {
+impl<InputIterator> TextTransformation<InputIterator> {
     pub fn new(char_iterator: InputIterator, text_transform: TextTransform) -> Self {
         Self {
             char_iterator,
diff --git a/components/layout_2020/fragment_tree/base_fragment.rs b/components/layout_2020/fragment_tree/base_fragment.rs
index d84dde30111..ac29bcc976d 100644
--- a/components/layout_2020/fragment_tree/base_fragment.rs
+++ b/components/layout_2020/fragment_tree/base_fragment.rs
@@ -117,7 +117,7 @@ impl Tag {
         self.pseudo.is_some()
     }
 
-    pub(crate) fn to_display_list_fragment_id(&self) -> u64 {
+    pub(crate) fn to_display_list_fragment_id(self) -> u64 {
         let fragment_type = match self.pseudo {
             Some(PseudoElement::Before) => FragmentType::BeforePseudoContent,
             Some(PseudoElement::After) => FragmentType::AfterPseudoContent,
diff --git a/components/layout_2020/fragment_tree/box_fragment.rs b/components/layout_2020/fragment_tree/box_fragment.rs
index 031285360a7..6f191b25a58 100644
--- a/components/layout_2020/fragment_tree/box_fragment.rs
+++ b/components/layout_2020/fragment_tree/box_fragment.rs
@@ -74,6 +74,7 @@ pub(crate) struct BoxFragment {
 }
 
 impl BoxFragment {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         base_fragment_info: BaseFragmentInfo,
         style: ServoArc<ComputedValues>,
@@ -108,6 +109,7 @@ impl BoxFragment {
         )
     }
 
+    #[allow(clippy::too_many_arguments)]
     pub fn new_with_overconstrained(
         base_fragment_info: BaseFragmentInfo,
         style: ServoArc<ComputedValues>,
diff --git a/components/layout_2020/fragment_tree/hoisted_shared_fragment.rs b/components/layout_2020/fragment_tree/hoisted_shared_fragment.rs
index 62822d4d610..ee6ce9870d6 100644
--- a/components/layout_2020/fragment_tree/hoisted_shared_fragment.rs
+++ b/components/layout_2020/fragment_tree/hoisted_shared_fragment.rs
@@ -56,16 +56,12 @@ pub(crate) enum AbsoluteBoxOffsets {
 
 impl AbsoluteBoxOffsets {
     pub(crate) fn both_specified(&self) -> bool {
-        match self {
-            AbsoluteBoxOffsets::Both { .. } => true,
-            _ => false,
-        }
+        matches!(self, AbsoluteBoxOffsets::Both { .. })
     }
 
     pub(crate) fn adjust_offset(&mut self, new_offset: Length) {
-        match *self {
-            AbsoluteBoxOffsets::StaticStart { ref mut start } => *start = new_offset,
-            _ => (),
+        if let AbsoluteBoxOffsets::StaticStart { ref mut start } = *self {
+            *start = new_offset
         }
     }
 }
diff --git a/components/layout_2020/fragment_tree/mod.rs b/components/layout_2020/fragment_tree/mod.rs
index 4579638685a..8738f2a6af7 100644
--- a/components/layout_2020/fragment_tree/mod.rs
+++ b/components/layout_2020/fragment_tree/mod.rs
@@ -6,6 +6,7 @@ mod base_fragment;
 mod box_fragment;
 mod containing_block;
 mod fragment;
+#[allow(clippy::module_inception)]
 mod fragment_tree;
 mod hoisted_shared_fragment;
 mod positioning_fragment;
diff --git a/components/layout_2020/query.rs b/components/layout_2020/query.rs
index e7e8cdf8667..c4cab2c0b13 100644
--- a/components/layout_2020/query.rs
+++ b/components/layout_2020/query.rs
@@ -505,12 +505,9 @@ fn process_offset_parent_query_inner(
             // "If any of the following holds true return null and terminate
             // this algorithm: [...] The element’s computed value of the
             // `position` property is `fixed`."
-            let is_fixed = match fragment {
-                Fragment::Box(fragment) if fragment.style.get_box().position == Position::Fixed => {
-                    true
-                },
-                _ => false,
-            };
+            let is_fixed = matches!(
+                fragment, Fragment::Box(fragment) if fragment.style.get_box().position == Position::Fixed
+            );
 
             if is_body_element {
                 // "If the element is the HTML body element or [...] return zero
diff --git a/components/layout_2020/style_ext.rs b/components/layout_2020/style_ext.rs
index b4a5325eaca..233bdca0076 100644
--- a/components/layout_2020/style_ext.rs
+++ b/components/layout_2020/style_ext.rs
@@ -88,6 +88,7 @@ pub(crate) enum DisplayInside {
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[allow(clippy::enum_variant_names)]
 /// <https://drafts.csswg.org/css-display-3/#layout-specific-display>
 pub(crate) enum DisplayLayoutInternal {
     TableCaption,
diff --git a/components/layout_2020/table/construct.rs b/components/layout_2020/table/construct.rs
index b43861ff3c2..5aff025c1ce 100644
--- a/components/layout_2020/table/construct.rs
+++ b/components/layout_2020/table/construct.rs
@@ -704,8 +704,7 @@ where
                     });
 
                     let previous_text_decoration_line = self.current_text_decoration_line;
-                    self.current_text_decoration_line =
-                        self.current_text_decoration_line | info.style.clone_text_decoration_line();
+                    self.current_text_decoration_line |= info.style.clone_text_decoration_line();
 
                     let new_row_group_index = self.builder.table.row_groups.len() - 1;
                     self.current_row_group_index = Some(new_row_group_index);
@@ -953,6 +952,7 @@ where
         contents: Contents,
         box_slot: BoxSlot<'dom>,
     ) {
+        #[allow(clippy::collapsible_match)] //// TODO: Remove once the other cases are handled
         match display {
             DisplayGeneratingBox::LayoutInternal(internal) => match internal {
                 DisplayLayoutInternal::TableCell => {
diff --git a/components/layout_2020/table/layout.rs b/components/layout_2020/table/layout.rs
index ec538864533..1ecc1baa447 100644
--- a/components/layout_2020/table/layout.rs
+++ b/components/layout_2020/table/layout.rs
@@ -374,8 +374,7 @@ impl<'a> TableLayout<'a> {
         // >   * 100% minus the sum of the intrinsic percentage width of all prior columns in
         // >     the table (further left when direction is "ltr" (right for "rtl"))
         let mut total_intrinsic_percentage_width = 0.;
-        for column_index in 0..self.table.size.width {
-            let column_measure = &mut column_measures[column_index];
+        for column_measure in column_measures.iter_mut() {
             let final_intrinsic_percentage_width = column_measure
                 .percentage
                 .0
@@ -822,7 +821,7 @@ impl<'a> TableLayout<'a> {
 
     /// This is an implementation of *Distributing excess width to columns* from
     /// <https://drafts.csswg.org/css-tables/#distributing-width-to-columns>.
-    fn distribute_extra_width_to_columns(&self, column_sizes: &mut Vec<Au>, column_sizes_sum: Au) {
+    fn distribute_extra_width_to_columns(&self, column_sizes: &mut [Au], column_sizes_sum: Au) {
         let all_columns = 0..self.table.size.width;
         let extra_inline_size = self.assignable_width - column_sizes_sum;
 
@@ -971,8 +970,8 @@ impl<'a> TableLayout<'a> {
         for row_index in 0..self.table.slots.len() {
             let row = &self.table.slots[row_index];
             let mut cells_laid_out_row = Vec::new();
-            for column_index in 0..row.len() {
-                let cell = match &row[column_index] {
+            for (column_index, slot) in row.iter().enumerate() {
+                let cell = match slot {
                     TableSlot::Cell(cell) => cell,
                     _ => {
                         cells_laid_out_row.push(None);
@@ -1088,6 +1087,7 @@ impl<'a> TableLayout<'a> {
         row_sizes
     }
 
+    #[allow(clippy::ptr_arg)] // Needs to be a vec because of the function above
     /// After doing layout of table rows, calculate final row size and distribute space across
     /// rowspanned cells. This follows the implementation of LayoutNG and the priority
     /// agorithm described at <https://github.com/w3c/csswg-drafts/issues/4418>.
@@ -1098,6 +1098,7 @@ impl<'a> TableLayout<'a> {
     ) {
         let mut cells_to_distribute = Vec::new();
         let mut total_percentage = 0.;
+        #[allow(clippy::needless_range_loop)] // It makes sense to use it here
         for row_index in 0..self.table.size.height {
             let row_measure = self
                 .table
@@ -1186,7 +1187,7 @@ impl<'a> TableLayout<'a> {
         &self,
         mut excess_size: Au,
         track_range: Range<usize>,
-        track_sizes: &mut Vec<Au>,
+        track_sizes: &mut [Au],
         percentage_resolution_size: Option<Au>,
         rowspan_distribution: bool,
     ) {