LibWeb: Make sure we always apply size constraints in IFC

Pre-compute the effective containing block width in the IFC constructor
and use that throughout.

Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp

@@ -24,6 +24,17 @@ InlineFormattingContext::InlineFormattingContext(FormattingState& state, BlockCo
     : FormattingContext(Type::Inline, state, containing_block, &parent)
     , m_containing_block_state(state.get(containing_block))
 {
+    switch (m_containing_block_state.width_constraint) {
+    case SizeConstraint::MinContent:
+        m_effective_containing_block_width = 0;
+        break;
+    case SizeConstraint::MaxContent:
+        m_effective_containing_block_width = INFINITY;
+        break;
+    default:
+        m_effective_containing_block_width = m_containing_block_state.content_width;
+        break;
+    }
 }
 
 InlineFormattingContext::~InlineFormattingContext() = default;
@@ -50,6 +61,11 @@ float InlineFormattingContext::leftmost_x_offset_at(float y) const
 
 float InlineFormattingContext::available_space_for_line(float y) const
 {
+    if (m_effective_containing_block_width == 0)
+        return 0;
+    if (!isfinite(m_effective_containing_block_width))
+        return INFINITY;
+
     // NOTE: Floats are relative to the BFC root box, not necessarily the containing block of this IFC.
     auto box_in_root_rect = margin_box_rect_in_ancestor_coordinate_space(containing_block(), parent().root(), m_state);
     float y_in_root = box_in_root_rect.y() + y;
@@ -58,7 +74,7 @@ float InlineFormattingContext::available_space_for_line(float y) const
     auto const& root_block_state = m_state.get(parent().root());
 
     space.left = max(space.left, m_containing_block_state.offset.x()) - m_containing_block_state.offset.x();
-    space.right = min(root_block_state.content_width - space.right, m_containing_block_state.offset.x() + m_containing_block_state.content_width);
+    space.right = min(root_block_state.content_width - space.right, m_containing_block_state.offset.x() + m_effective_containing_block_width);
 
     return space.right - space.left;
 }
@@ -71,7 +87,7 @@ void InlineFormattingContext::run(Box const&, LayoutMode layout_mode)
 
 void InlineFormattingContext::dimension_box_on_line(Box const& box, LayoutMode layout_mode)
 {
-    auto width_of_containing_block = CSS::Length::make_px(m_containing_block_state.content_width);
+    auto width_of_containing_block = CSS::Length::make_px(m_effective_containing_block_width);
     auto& box_state = m_state.get_mutable(box);
     auto const& computed_values = box.computed_values();
 
@@ -120,7 +136,7 @@ void InlineFormattingContext::dimension_box_on_line(Box const& box, LayoutMode l
             auto width = min(max(result.preferred_minimum_width, available_width), result.preferred_width);
             box_state.content_width = width;
         } else {
-            auto container_width = CSS::Length::make_px(m_containing_block_state.content_width);
+            auto container_width = CSS::Length::make_px(m_effective_containing_block_width);
             box_state.content_width = width_value.resolved(box, container_width).to_px(inline_block);
         }
         auto independent_formatting_context = layout_inside(inline_block, layout_mode);
@@ -144,7 +160,7 @@ void InlineFormattingContext::dimension_box_on_line(Box const& box, LayoutMode l
     dump_tree(box);
 }
 
-void InlineFormattingContext::apply_justification_to_fragments(FormattingState::NodeState const& containing_block_state, CSS::TextJustify text_justify, LineBox& line_box, bool is_last_line)
+void InlineFormattingContext::apply_justification_to_fragments(CSS::TextJustify text_justify, LineBox& line_box, bool is_last_line)
 {
     switch (text_justify) {
     case CSS::TextJustify::None:
@@ -156,11 +172,11 @@ void InlineFormattingContext::apply_justification_to_fragments(FormattingState::
         break;
     }
 
-    float excess_horizontal_space = containing_block_state.content_width - line_box.width();
+    float excess_horizontal_space = m_effective_containing_block_width - line_box.width();
 
     // Only justify the text if the excess horizontal space is less than or
     // equal to 10%, or if we are not looking at the last line box.
-    if (is_last_line && excess_horizontal_space / containing_block_state.content_width > text_justification_threshold)
+    if (is_last_line && excess_horizontal_space / m_effective_containing_block_width > text_justification_threshold)
         return;
 
     float excess_horizontal_space_including_whitespace = excess_horizontal_space;
@@ -276,7 +292,7 @@ void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
         for (size_t i = 0; i < line_boxes.size(); i++) {
             auto& line_box = line_boxes[i];
             auto is_last_line = i == line_boxes.size() - 1;
-            apply_justification_to_fragments(m_containing_block_state, text_justify, line_box, is_last_line);
+            apply_justification_to_fragments(text_justify, line_box, is_last_line);
         }
     }
 }

Userland/Libraries/LibWeb/Layout/InlineFormattingContext.h

@@ -30,11 +30,14 @@ public:
     float leftmost_x_offset_at(float y) const;
     float available_space_for_line(float y) const;
 
+    float effective_containing_block_width() const { return m_effective_containing_block_width; }
+
 private:
     void generate_line_boxes(LayoutMode);
-    void apply_justification_to_fragments(FormattingState::NodeState const& containing_block_state, CSS::TextJustify, LineBox&, bool is_last_line);
+    void apply_justification_to_fragments(CSS::TextJustify, LineBox&, bool is_last_line);
 
     FormattingState::NodeState const& m_containing_block_state;
+    float m_effective_containing_block_width { 0 };
 };
 
 }

Userland/Libraries/LibWeb/Layout/LineBuilder.cpp

@@ -35,20 +35,8 @@ void LineBuilder::begin_new_line(bool increment_y)
 {
     if (increment_y)
         m_current_y += max(m_max_height_on_current_line, m_context.containing_block().line_height());
-
-    switch (m_containing_block_state.width_constraint) {
-    case SizeConstraint::MinContent:
-        m_available_width_for_current_line = 0;
-        break;
-    case SizeConstraint::MaxContent:
-        m_available_width_for_current_line = INFINITY;
-        break;
-    default:
-        m_available_width_for_current_line = m_context.available_space_for_line(m_current_y);
-        break;
-    }
+    m_available_width_for_current_line = m_context.available_space_for_line(m_current_y);
     m_max_height_on_current_line = 0;
-
     m_last_line_needs_update = true;
 }
 
@@ -126,7 +114,7 @@ void LineBuilder::update_last_line()
 
     auto text_align = m_context.containing_block().computed_values().text_align();
     float x_offset = m_context.leftmost_x_offset_at(m_current_y);
-    float excess_horizontal_space = m_containing_block_state.content_width - line_box.width();
+    float excess_horizontal_space = m_context.effective_containing_block_width() - line_box.width();
 
     switch (text_align) {
     case CSS::TextAlign::Center: