Auto merge of #25445 - pylbrecht:ensure.path.quad, r=jdm

Ensure subpath for control point of CanvasRenderingContext2D.quadraticCurveTo()

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These changes are based on #25444.

---
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- [x] These changes fix part of #25331

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- [x] There are tests for these changes

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components/canvas/canvas_data.rs

@@ -771,6 +771,9 @@ impl<'a> CanvasData<'a> {
     }
 
     pub fn quadratic_curve_to(&mut self, cp: &Point2D<f32>, endpoint: &Point2D<f32>) {
+        if self.path_builder().current_point().is_none() {
+            self.path_builder().move_to(cp);
+        }
         self.path_builder().quadratic_curve_to(cp, endpoint);
     }