Fix Pen tool race condition when drawing handles fast, and stuck overlays (#1283)

* Fix pen tool with async

* Fix overlays staying too long

* Perhaps fix the transform issue

* Fix compile error

* Formatting

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

libraries/bezier-rs/src/subpath/manipulators.rs

@@ -31,11 +31,13 @@ impl<ManipulatorGroupId: crate::Identifier> Subpath<ManipulatorGroupId> {
 
 	/// Insert a manipulator group at an index.
 	pub fn insert_manipulator_group(&mut self, index: usize, group: ManipulatorGroup<ManipulatorGroupId>) {
+		assert!(group.is_finite(), "Inserting non finite manipulator group");
 		self.manipulator_groups.insert(index, group)
 	}
 
 	/// Push a manipulator group to the end.
 	pub fn push_manipulator_group(&mut self, group: ManipulatorGroup<ManipulatorGroupId>) {
+		assert!(group.is_finite(), "Pushing non finite manipulator group");
 		self.manipulator_groups.push(group)
 	}
 

libraries/bezier-rs/src/subpath/structs.rs

@@ -106,6 +106,11 @@ impl<ManipulatorGroupId: crate::Identifier> ManipulatorGroup<ManipulatorGroupId>
 		self.in_handle = self.in_handle.map(|in_handle| affine_transform.transform_point2(in_handle));
 		self.out_handle = self.out_handle.map(|out_handle| affine_transform.transform_point2(out_handle));
 	}
+
+	/// Are all handles at finite positions
+	pub fn is_finite(&self) -> bool {
+		self.anchor.is_finite() && self.in_handle.map_or(true, |handle| handle.is_finite()) && self.out_handle.map_or(true, |handle| handle.is_finite())
+	}
 }
 
 #[derive(Copy, Clone)]