LibWeb: Null-check surface before allocating painter for context2d

Fixes https://github.com/LadybirdBrowser/ladybird/issues/2755
This commit is contained in:
Aliaksandr Kalenik 2024-12-04 16:22:27 +01:00 committed by Alexander Kalenik
parent 1081a7f3e2
commit 72f093ba9f
Notes: github-actions[bot] 2024-12-04 15:59:49 +00:00
3 changed files with 17 additions and 3 deletions

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@ -199,8 +199,9 @@ void CanvasRenderingContext2D::did_draw(Gfx::FloatRect const&)
Gfx::Painter* CanvasRenderingContext2D::painter()
{
if (!canvas_element().surface()) {
allocate_painting_surface_if_needed();
allocate_painting_surface_if_needed();
auto surface = canvas_element().surface();
if (!m_painter && surface) {
canvas_element().document().invalidate_display_list();
m_painter = make<Gfx::PainterSkia>(*canvas_element().surface());
}
@ -217,7 +218,7 @@ void CanvasRenderingContext2D::set_size(Gfx::IntSize const& size)
void CanvasRenderingContext2D::allocate_painting_surface_if_needed()
{
if (m_surface)
if (m_surface || m_size.is_empty())
return;
auto skia_backend_context = canvas_element().navigable()->traversable_navigable()->skia_backend_context();
m_surface = Gfx::PaintingSurface::create_with_size(skia_backend_context, canvas_element().bitmap_size_for_canvas(), Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied);

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@ -0,0 +1 @@
PASS (didn't crash!)

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@ -0,0 +1,12 @@
<!DOCTYPE html>
<script src="../include.js"></script>
<canvas id="myCanvas" width="0" height="0"></canvas>
<script>
test(() => {
const canvas = document.getElementById('myCanvas');
const ctx = canvas.getContext('2d');
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, canvas.width, canvas.height);
println("PASS (didn't crash!)");
});
</script>