De duplicate Overlay render messages (#520)

editor/src/communication/dispatcher.rs

@@ -30,6 +30,7 @@ struct DispatcherMessageHandlers {
 // In addition, these messages do not change any state in the backend (aside from caches).
 const SIDE_EFFECT_FREE_MESSAGES: &[MessageDiscriminant] = &[
 	MessageDiscriminant::Portfolio(PortfolioMessageDiscriminant::Document(DocumentMessageDiscriminant::RenderDocument)),
+	MessageDiscriminant::Portfolio(PortfolioMessageDiscriminant::Document(DocumentMessageDiscriminant::Overlays(OverlaysMessageDiscriminant::Rerender))),
 	MessageDiscriminant::Portfolio(PortfolioMessageDiscriminant::Document(DocumentMessageDiscriminant::FolderChanged)),
 	MessageDiscriminant::Frontend(FrontendMessageDiscriminant::UpdateDocumentLayer),
 	MessageDiscriminant::Frontend(FrontendMessageDiscriminant::DisplayDocumentLayerTreeStructure),

editor/src/document/overlays_message_handler.rs

@@ -18,16 +18,15 @@ impl MessageHandler<OverlaysMessage, bool> for OverlaysMessageHandler {
 			// Sub-messages
 			#[remain::unsorted]
 			DispatchOperation(operation) => match self.overlays_graphene_document.handle_operation(&operation) {
-				Ok(_) => (),
+				Ok(_) => responses.push_back(OverlaysMessage::Rerender.into()),
 				Err(e) => log::error!("OverlaysError: {:?}", e),
 			},
 
 			// Messages
 			ClearAllOverlays => todo!(),
-			Rerender => (),
-		}
-
+			Rerender =>
 			// Render overlays
+			{
 				responses.push_back(
 					FrontendMessage::UpdateDocumentOverlays {
 						svg: if overlays_visible {
@@ -37,7 +36,9 @@ impl MessageHandler<OverlaysMessage, bool> for OverlaysMessageHandler {
 						},
 					}
 					.into(),
-		);
+				)
+			}
+		}
 	}
 
 	fn actions(&self) -> ActionList {