diff --git a/components/layout/flow/inline/mod.rs b/components/layout/flow/inline/mod.rs
index da77a4ea840..7034144a79d 100644
--- a/components/layout/flow/inline/mod.rs
+++ b/components/layout/flow/inline/mod.rs
@@ -333,6 +333,10 @@ struct LineUnderConstruction {
/// indicates that the next run that exceeds the line length can cause a line break.
has_content: bool,
+ /// Whether any active linebox has added some inline-axis padding, border or margin
+ /// to this line.
+ has_inline_pbm: bool,
+
/// Whether or not there are floats that did not fit on the current line. Before
/// the [`LineItem`]s of this line are laid out, these floats will need to be
/// placed directly below this line, but still as children of this line's Fragments.
@@ -356,6 +360,7 @@ impl LineUnderConstruction {
start_position,
max_block_size: LineBlockSizes::zero(),
has_content: false,
+ has_inline_pbm: false,
has_floats_waiting_to_be_placed: false,
placement_among_floats: OnceCell::new(),
line_items: Vec::new(),
@@ -558,6 +563,10 @@ struct UnbreakableSegmentUnderConstruction {
/// a line break.
has_content: bool,
+ /// Whether any active linebox has added some inline-axis padding, border or margin
+ /// to this line segment.
+ has_inline_pbm: bool,
+
/// The inline size of any trailing whitespace in this segment.
trailing_whitespace_size: Au,
}
@@ -574,6 +583,7 @@ impl UnbreakableSegmentUnderConstruction {
line_items: Vec::new(),
inline_box_hierarchy_depth: None,
has_content: false,
+ has_inline_pbm: false,
trailing_whitespace_size: Au::zero(),
}
}
@@ -732,8 +742,9 @@ pub(super) struct InlineFormattingContextLayout<'layout_data> {
/// is encountered.
pub have_deferred_soft_wrap_opportunity: bool,
- /// Whether or not this InlineFormattingContext has processed any in flow content at all.
- had_inflow_content: bool,
+ /// Whether or not this InlineFormattingContext contains line boxes, excluding
+ /// [phantom line boxes](https://drafts.csswg.org/css-inline-3/#phantom-line-box).
+ has_line_boxes: bool,
/// Whether or not the layout of this InlineFormattingContext depends on the block size
/// of its container for the purposes of flexbox layout.
@@ -837,9 +848,15 @@ impl InlineFormattingContextLayout<'_> {
}
if inline_box.is_first_split {
- self.current_line_segment.inline_size += inline_box_state.pbm.padding.inline_start +
- inline_box_state.pbm.border.inline_start +
- inline_box_state.pbm.margin.inline_start.auto_is(Au::zero);
+ let padding = inline_box_state.pbm.padding.inline_start;
+ let border = inline_box_state.pbm.border.inline_start;
+ let margin = inline_box_state.pbm.margin.inline_start.auto_is(Au::zero);
+ // We can't just check if the sum is zero because the margin can be negative,
+ // we need to check the values separately.
+ if !padding.is_zero() || !border.is_zero() || !margin.is_zero() {
+ self.current_line_segment.has_inline_pbm = true;
+ }
+ self.current_line_segment.inline_size += padding + border + margin;
self.current_line_segment
.line_items
.push(LineItem::InlineStartBoxPaddingBorderMargin(
@@ -881,10 +898,15 @@ impl InlineFormattingContextLayout<'_> {
}
if inline_box_state.is_last_fragment {
- let pbm_end = inline_box_state.pbm.padding.inline_end +
- inline_box_state.pbm.border.inline_end +
- inline_box_state.pbm.margin.inline_end.auto_is(Au::zero);
- self.current_line_segment.inline_size += pbm_end;
+ let padding = inline_box_state.pbm.padding.inline_end;
+ let border = inline_box_state.pbm.border.inline_end;
+ let margin = inline_box_state.pbm.margin.inline_end.auto_is(Au::zero);
+ // We can't just check if the sum is zero because the margin can be negative,
+ // we need to check the values separately.
+ if !padding.is_zero() || !border.is_zero() || !margin.is_zero() {
+ self.current_line_segment.has_inline_pbm = true;
+ }
+ self.current_line_segment.inline_size += padding + border + margin;
self.current_line_segment
.line_items
.push(LineItem::InlineEndBoxPaddingBorderMargin(
@@ -984,10 +1006,16 @@ impl InlineFormattingContextLayout<'_> {
justification_adjustment,
);
- if line_to_layout.has_content {
+ // https://drafts.csswg.org/css-inline-3/#invisible-line-boxes
+ // > Line boxes that contain no text, no preserved white space, no inline boxes with non-zero
+ // > inline-axis margins, padding, or borders, and no other in-flow content (such as atomic
+ // > inlines or ruby annotations), and do not end with a forced line break are phantom line boxes.
+ // > Such boxes [...] must be treated as not existing for any other layout or rendering purpose.
+ if line_to_layout.has_content || line_to_layout.has_inline_pbm {
let baseline = baseline_offset + block_start_position;
self.baselines.first.get_or_insert(baseline);
self.baselines.last = Some(baseline);
+ self.has_line_boxes = true;
}
// If the line doesn't have any fragments, we don't need to add a containing fragment for it.
@@ -1350,8 +1378,6 @@ impl InlineFormattingContextLayout<'_> {
SegmentContentFlags::empty(),
);
}
-
- self.had_inflow_content = true;
}
pub(super) fn possibly_flush_deferred_forced_line_break(&mut self) {
@@ -1486,7 +1512,6 @@ impl InlineFormattingContextLayout<'_> {
}
if !flags.is_collapsible_whitespace() {
self.current_line_segment.has_content = true;
- self.had_inflow_content = true;
}
// This may or may not include the size of the strut depending on the quirks mode setting.
@@ -1601,6 +1626,7 @@ impl InlineFormattingContextLayout<'_> {
self.current_line.line_items.extend(segment_items);
self.current_line.has_content |= self.current_line_segment.has_content;
+ self.current_line.has_inline_pbm |= self.current_line_segment.has_inline_pbm;
self.current_line_segment.reset();
}
@@ -1792,7 +1818,7 @@ impl InlineFormattingContext {
linebreak_before_new_content: false,
deferred_br_clear: Clear::None,
have_deferred_soft_wrap_opportunity: false,
- had_inflow_content: false,
+ has_line_boxes: false,
depends_on_block_constraints: false,
white_space_collapse: style_text.white_space_collapse,
text_wrap_mode: style_text.text_wrap_mode,
@@ -1846,7 +1872,7 @@ impl InlineFormattingContext {
let mut collapsible_margins_in_children = CollapsedBlockMargins::zero();
let content_block_size = layout.current_line.start_position.block;
- collapsible_margins_in_children.collapsed_through = !layout.had_inflow_content &&
+ collapsible_margins_in_children.collapsed_through = !layout.has_line_boxes &&
content_block_size.is_zero() &&
collapsible_with_parent_start_margin.0;
diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index b5f49a7e567..f4a5a871ff8 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -210635,6 +210635,86 @@
]
]
},
+ "model": {
+ "phantom-line-boxes-001.html": [
+ "da0e9095b7a37e6b4a897269e753175c68039a34",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
+ "phantom-line-boxes-002.html": [
+ "c180a9bf3b5c4cda3e281d84bb36b6d8b2bae91c",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
+ "phantom-line-boxes-003.html": [
+ "633aa9dfba8d81d515c807c66074b77c73dbfee4",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
+ "phantom-line-boxes-004.html": [
+ "0b4f7737ee21b4490e951ce1677772b9d1ae2d71",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
+ "phantom-line-boxes-005.html": [
+ "dd2620294412fab68af218f30e470a3003255dd4",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
+ "phantom-line-boxes-006.html": [
+ "7b5a43cbf811680087429abe5b0236d1221f28d4",
+ [
+ null,
+ [
+ [
+ "/css/reference/ref-filled-green-200px-square.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ]
+ },
"text-box-trim": {
"border-padding-001.html": [
"9c25c42a1def684b364e98dc9d6233cd5c700519",
diff --git a/tests/wpt/tests/css/css-inline/model/phantom-line-boxes-001.html b/tests/wpt/tests/css/css-inline/model/phantom-line-boxes-001.html
new file mode 100644
index 00000000000..da0e9095b7a
--- /dev/null
+++ b/tests/wpt/tests/css/css-inline/model/phantom-line-boxes-001.html
@@ -0,0 +1,49 @@
+
+CSS Inline Layout Model: Phantom Line Boxes
+
+
+
+
+
+
+
+
+
+
Test passes if there is a filled green square and no red.