LibWeb: Don't try to paint SVG elements transformed to zero size

Otherwise, the Gfx::Painter will get choked up on NaNs and start
infinitely splitting paths till it OOMs.

Userland/Libraries/LibWeb/Layout/SVGGeometryBox.cpp

@@ -25,7 +25,7 @@ CSSPixelPoint SVGGeometryBox::viewbox_origin() const
     return { svg_box->view_box().value().min_x, svg_box->view_box().value().min_y };
 }
 
-Gfx::AffineTransform SVGGeometryBox::layout_transform() const
+Optional<Gfx::AffineTransform> SVGGeometryBox::layout_transform() const
 {
     auto& geometry_element = dom_node();
     auto transform = geometry_element.get_transform();
@@ -37,9 +37,12 @@ Gfx::AffineTransform SVGGeometryBox::layout_transform() const
         // Note: SVGFormattingContext has already done the scaling based on the viewbox,
         // we now have to derive what it was from the original bounding box size.
         // FIXME: It would be nice if we could store the transform from layout somewhere, so we don't have to solve for it here.
+        auto original_bounding_box = Gfx::AffineTransform {}.translate(-origin).multiply(transform).map(const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().bounding_box());
+        // If the transform (or path) results in a empty box we can't display this.
+        if (original_bounding_box.is_empty())
+            return {};
         auto scaled_width = paint_box()->content_width().value();
         auto scaled_height = paint_box()->content_height().value();
-        auto original_bounding_box = Gfx::AffineTransform {}.translate(-origin).multiply(transform).map(const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().bounding_box());
         scaling = min(scaled_width / original_bounding_box.width(), scaled_height / original_bounding_box.height());
         auto scaled_bounding_box = original_bounding_box.scaled(scaling, scaling);
         paint_offset = (paint_box()->absolute_rect().location() - svg_box->paint_box()->absolute_rect().location()).to_type<float>() - scaled_bounding_box.location();

Userland/Libraries/LibWeb/Layout/SVGGeometryBox.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/Optional.h>
 #include <LibWeb/Layout/SVGGraphicsBox.h>
 #include <LibWeb/SVG/SVGGeometryElement.h>
 
@@ -21,7 +22,7 @@ public:
     SVG::SVGGeometryElement& dom_node() { return static_cast<SVG::SVGGeometryElement&>(SVGGraphicsBox::dom_node()); }
     SVG::SVGGeometryElement const& dom_node() const { return static_cast<SVG::SVGGeometryElement const&>(SVGGraphicsBox::dom_node()); }
 
-    Gfx::AffineTransform layout_transform() const;
+    Optional<Gfx::AffineTransform> layout_transform() const;
 
     virtual JS::GCPtr<Painting::Paintable> create_paintable() const override;
 

Userland/Libraries/LibWeb/Painting/SVGGeometryPaintable.cpp

@@ -33,10 +33,12 @@ Optional<HitTestResult> SVGGeometryPaintable::hit_test(CSSPixelPoint position, H
     if (!result.has_value())
         return {};
     auto& geometry_element = layout_box().dom_node();
-    auto transformed_bounding_box = layout_box().layout_transform().map_to_quad(
+    if (auto transform = layout_box().layout_transform(); transform.has_value()) {
-        const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().bounding_box());
+        auto transformed_bounding_box = transform->map_to_quad(
-    if (!transformed_bounding_box.contains(position.to_type<float>()))
+            const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().bounding_box());
-        return {};
+        if (!transformed_bounding_box.contains(position.to_type<float>()))
+            return {};
+    }
     return result;
 }
 
@@ -56,6 +58,7 @@ void SVGGeometryPaintable::paint(PaintContext& context, PaintPhase phase) const
     auto& svg_context = context.svg_context();
 
     // FIXME: This should not be trucated to an int.
+    Gfx::PainterStateSaver save_painter { context.painter() };
     auto offset = context.floored_device_point(svg_context.svg_element_position()).to_type<int>().to_type<float>();
     painter.translate(offset);
 
@@ -65,7 +68,10 @@ void SVGGeometryPaintable::paint(PaintContext& context, PaintPhase phase) const
     context.painter().add_clip_rect(context.enclosing_device_rect(absolute_rect()).to_type<int>());
     auto css_scale = context.device_pixels_per_css_pixel();
 
-    Gfx::Path path = const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().copy_transformed(Gfx::AffineTransform {}.scale(css_scale, css_scale).multiply(layout_box().layout_transform()));
+    auto transform = layout_box().layout_transform();
+    if (!transform.has_value())
+        return;
+    Gfx::Path path = const_cast<SVG::SVGGeometryElement&>(geometry_element).get_path().copy_transformed(Gfx::AffineTransform {}.scale(css_scale, css_scale).multiply(*transform));
 
     if (auto fill_color = geometry_element.fill_color().value_or(svg_context.fill_color()); fill_color.alpha() > 0) {
         // We need to fill the path before applying the stroke, however the filled
@@ -87,9 +93,6 @@ void SVGGeometryPaintable::paint(PaintContext& context, PaintPhase phase) const
             stroke_color,
             geometry_element.stroke_width().value_or(svg_context.stroke_width()) * context.device_pixels_per_css_pixel());
     }
-
-    painter.translate(-offset);
-    context.painter().clear_clip_rect();
 }
 
 }