LibWeb: Use preferred flex item sizes as min/max-content contribution

When a flex item has a specific preferred size, that size should be its
contribution to the containers intrinsic sizes.

This fixes an issue on Patreon where the logo would cover the entire
viewport since the SVG had a large intrinsic size but the flex item
containing it had a small specified size in CSS.

2 files changed, 27 insertions, 14 deletions

diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
index 9604812099..99f934da02 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
@@ -1737,14 +1737,26 @@ float FlexFormattingContext::calculate_main_max_content_contribution(FlexItem co
     return item.add_main_margin_box_sizes(clamped_inner_size);
 }
 
+bool FlexFormattingContext::should_treat_main_size_as_auto(Box const& box) const
+{
+    if (is_row_layout())
+        return should_treat_width_as_auto(box, m_available_space_for_items->space);
+    return should_treat_height_as_auto(box, m_available_space_for_items->space);
+}
+
+bool FlexFormattingContext::should_treat_cross_size_as_auto(Box const& box) const
+{
+    if (is_row_layout())
+        return should_treat_height_as_auto(box, m_available_space_for_items->space);
+    return should_treat_width_as_auto(box, m_available_space_for_items->space);
+}
+
 float FlexFormattingContext::calculate_cross_min_content_contribution(FlexItem const& item, bool resolve_percentage_min_max_sizes) const
 {
-    auto larger_size = [&] {
-        auto inner_min_content_size = calculate_min_content_cross_size(item);
-        if (computed_cross_size(item.box).is_auto())
-            return inner_min_content_size;
-        auto inner_preferred_size = !is_row_layout() ? get_pixel_width(item.box, computed_cross_size(item.box)) : get_pixel_height(item.box, computed_cross_size(item.box));
-        return max(inner_min_content_size, inner_preferred_size);
+    auto size = [&] {
+        if (should_treat_cross_size_as_auto(item.box))
+            return calculate_min_content_cross_size(item);
+        return !is_row_layout() ? get_pixel_width(item.box, computed_cross_size(item.box)) : get_pixel_height(item.box, computed_cross_size(item.box));
     }();
 
     auto const& computed_min_size = this->computed_cross_min_size(item.box);
@@ -1753,19 +1765,17 @@ float FlexFormattingContext::calculate_cross_min_content_contribution(FlexItem c
     auto clamp_min = (!computed_min_size.is_auto() && (resolve_percentage_min_max_sizes || !computed_min_size.contains_percentage())) ? specified_cross_min_size(item.box) : 0;
     auto clamp_max = (!computed_max_size.is_none() && (resolve_percentage_min_max_sizes || !computed_max_size.contains_percentage())) ? specified_cross_max_size(item.box) : NumericLimits<float>::max();
 
-    auto clamped_inner_size = css_clamp(larger_size, clamp_min, clamp_max);
+    auto clamped_inner_size = css_clamp(size, clamp_min, clamp_max);
 
     return item.add_cross_margin_box_sizes(clamped_inner_size);
 }
 
 float FlexFormattingContext::calculate_cross_max_content_contribution(FlexItem const& item, bool resolve_percentage_min_max_sizes) const
 {
-    auto larger_size = [&] {
-        auto inner_max_content_size = calculate_max_content_cross_size(item);
-        if (computed_cross_size(item.box).is_auto())
-            return inner_max_content_size;
-        auto inner_preferred_size = !is_row_layout() ? get_pixel_width(item.box, computed_cross_size(item.box)) : get_pixel_height(item.box, computed_cross_size(item.box));
-        return max(inner_max_content_size, inner_preferred_size);
+    auto size = [&] {
+        if (should_treat_cross_size_as_auto(item.box))
+            return calculate_max_content_cross_size(item);
+        return !is_row_layout() ? get_pixel_width(item.box, computed_cross_size(item.box)) : get_pixel_height(item.box, computed_cross_size(item.box));
     }();
 
     auto const& computed_min_size = this->computed_cross_min_size(item.box);
@@ -1774,7 +1784,7 @@ float FlexFormattingContext::calculate_cross_max_content_contribution(FlexItem c
     auto clamp_min = (!computed_min_size.is_auto() && (resolve_percentage_min_max_sizes || !computed_min_size.contains_percentage())) ? specified_cross_min_size(item.box) : 0;
     auto clamp_max = (!computed_max_size.is_none() && (resolve_percentage_min_max_sizes || !computed_max_size.contains_percentage())) ? specified_cross_max_size(item.box) : NumericLimits<float>::max();
 
-    auto clamped_inner_size = css_clamp(larger_size, clamp_min, clamp_max);
+    auto clamped_inner_size = css_clamp(size, clamp_min, clamp_max);
 
     return item.add_cross_margin_box_sizes(clamped_inner_size);
 }
diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
index 0fc842817e..fa06620131 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
@@ -30,6 +30,9 @@ public:
     virtual Gfx::FloatPoint calculate_static_position(Box const&) const override;
 
 private:
+    [[nodiscard]] bool should_treat_main_size_as_auto(Box const&) const;
+    [[nodiscard]] bool should_treat_cross_size_as_auto(Box const&) const;
+
     void dump_items() const;
 
     struct DirectionAgnosticMargins {