diff --git a/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt b/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt
new file mode 100644
index 0000000000..f79242478a
--- /dev/null
+++ b/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt
@@ -0,0 +1,11 @@
+Viewport <#document> at (0,0) content-size 800x600 children: not-inline
+ BlockContainer at (0,0) content-size 800x66 children: not-inline
+ BlockContainer
at (8,8) content-size 784x50 children: inline
+ line 0 width: 89.726562, height: 50, bottom: 50, baseline: 16.914062
+ frag 0 from Box start: 0, length: 0, rect: [28,38 49.726562x0]
+ Box at (28,38) content-size 49.726562x0 flex-container(row) children: not-inline
+ BlockContainer <(anonymous)> at (28,27.082031) content-size 49.726562x21.835937 flex-item children: inline
+ line 0 width: 49.726562, height: 21.835937, bottom: 21.835937, baseline: 16.914062
+ frag 0 from TextNode start: 0, length: 5, rect: [28,27.082031 49.726562x21.835937]
+ "Hello"
+ TextNode <#text>
diff --git a/Tests/LibWeb/Layout/input/box-sizing-border-box-for-definite-sizes-without-layout.html b/Tests/LibWeb/Layout/input/box-sizing-border-box-for-definite-sizes-without-layout.html
new file mode 100644
index 0000000000..0911ac1b2a
--- /dev/null
+++ b/Tests/LibWeb/Layout/input/box-sizing-border-box-for-definite-sizes-without-layout.html
@@ -0,0 +1,14 @@
+Hello
\ No newline at end of file
diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
index db62b6c526..32ef24b418 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
@@ -1088,15 +1088,7 @@ void FlexFormattingContext::determine_hypothetical_cross_size_of_item(FlexItem&
return;
}
- auto cross_size = [&]() {
- if (item.box->computed_values().box_sizing() == CSS::BoxSizing::BorderBox && !should_treat_cross_size_as_auto(item.box)) {
- return max(CSSPixels(0.0f), inner_cross_size(item.box) - item.padding.cross_before - item.padding.cross_after - item.borders.cross_before - item.borders.cross_after);
- }
-
- return inner_cross_size(item.box);
- }();
-
- item.hypothetical_cross_size = css_clamp(cross_size, clamp_min, clamp_max);
+ item.hypothetical_cross_size = css_clamp(inner_cross_size(item.box), clamp_min, clamp_max);
return;
}
diff --git a/Userland/Libraries/LibWeb/Layout/LayoutState.cpp b/Userland/Libraries/LibWeb/Layout/LayoutState.cpp
index d6d77cab55..75342d1572 100644
--- a/Userland/Libraries/LibWeb/Layout/LayoutState.cpp
+++ b/Userland/Libraries/LibWeb/Layout/LayoutState.cpp
@@ -229,6 +229,29 @@ void LayoutState::UsedValues::set_node(NodeWithStyleAndBoxModelMetrics& node, Us
auto const& computed_values = node.computed_values();
+ auto adjust_for_box_sizing = [&](CSSPixels unadjusted_pixels, CSS::Size const& computed_size, bool width) -> CSSPixels {
+ // box-sizing: content-box and/or automatic size don't require any adjustment.
+ if (computed_values.box_sizing() == CSS::BoxSizing::ContentBox || computed_size.is_auto())
+ return unadjusted_pixels;
+
+ // box-sizing: border-box requires us to subtract the relevant border and padding from the size.
+ CSSPixels border_and_padding;
+
+ if (width) {
+ border_and_padding = CSSPixels(computed_values.border_left().width)
+ + computed_values.padding().left().resolved(*m_node, CSS::Length::make_px(containing_block_used_values->content_width())).resolved(*m_node).to_px(*m_node)
+ + CSSPixels(computed_values.border_right().width)
+ + computed_values.padding().right().resolved(*m_node, CSS::Length::make_px(containing_block_used_values->content_width())).resolved(*m_node).to_px(*m_node);
+ } else {
+ border_and_padding = CSSPixels(computed_values.border_top().width)
+ + computed_values.padding().top().resolved(*m_node, CSS::Length::make_px(containing_block_used_values->content_width())).resolved(*m_node).to_px(*m_node)
+ + CSSPixels(computed_values.border_bottom().width)
+ + computed_values.padding().bottom().resolved(*m_node, CSS::Length::make_px(containing_block_used_values->content_width())).resolved(*m_node).to_px(*m_node);
+ }
+
+ return unadjusted_pixels - border_and_padding;
+ };
+
auto is_definite_size = [&](CSS::Size const& size, CSSPixels& resolved_definite_size, bool width) {
// A size that can be determined without performing layout; that is,
// a ,
@@ -270,22 +293,22 @@ void LayoutState::UsedValues::set_node(NodeWithStyleAndBoxModelMetrics& node, Us
auto containing_block_size_as_length = width
? CSS::Length::make_px(containing_block_used_values->content_width())
: CSS::Length::make_px(containing_block_used_values->content_height());
- resolved_definite_size = size.calculated().resolve_length_percentage(node, containing_block_size_as_length).value_or(CSS::Length::make_auto()).to_px(node);
+ resolved_definite_size = adjust_for_box_sizing(size.calculated().resolve_length_percentage(node, containing_block_size_as_length).value_or(CSS::Length::make_auto()).to_px(node), size, width);
return true;
}
- resolved_definite_size = size.calculated().resolve_length(node)->to_px(node);
+ resolved_definite_size = adjust_for_box_sizing(size.calculated().resolve_length(node)->to_px(node), size, width);
return true;
}
if (size.is_length()) {
VERIFY(!size.is_auto()); // This should have been covered by the Size::is_auto() branch above.
- resolved_definite_size = size.length().to_px(node);
+ resolved_definite_size = adjust_for_box_sizing(size.length().to_px(node), size, width);
return true;
}
if (size.is_percentage()) {
if (containing_block_has_definite_size) {
auto containing_block_size = width ? containing_block_used_values->content_width() : containing_block_used_values->content_height();
- resolved_definite_size = containing_block_size * size.percentage().as_fraction();
+ resolved_definite_size = adjust_for_box_sizing(containing_block_size * size.percentage().as_fraction(), size, width);
return true;
}
return false;