Crash on iOS, when a Viro component being unmounted

[ariel-bentu]

Steps to reproduce:

1. Start a fresh react-native app:

npx @react-native-community/cli init ViroBug --version 0.76
cd ViroBug
npm i @reactvision/react-viro

2. Modify Podfile

  pod 'ViroReact', :path => '../node_modules/@reactvision/react-viro/ios/'
  pod 'ViroKit', :path => '../node_modules/@reactvision/react-viro/ios/dist/ViroRenderer/'

3. Install pods:

cd iOS
pod install

4. Replace the App.tsx with this code:

import { Viro3DSceneNavigator, ViroAmbientLight, ViroBox, ViroCamera, ViroMaterials, ViroNode, ViroQuad, ViroScene, ViroSpotLight } from "@reactvision/react-viro";
import { forwardRef, useImperativeHandle, useRef, useState } from "react";
import { Button, SafeAreaView, View } from "react-native";


export default function App() {
    const sceneRef = useRef<any>(undefined);

    return (
        <SafeAreaView style={{ flex: 1 }} >
            <Button title="reload" onPress={() => sceneRef.current?.recreate()}></Button>

            <Viro3DSceneNavigator
                initialScene={{
                    scene: Scene1,

                    passProps: {
                        ref: sceneRef,
                    }
                }}
            />
        </SafeAreaView>
    );
}

export const Scene1 = forwardRef(({ }: any, ref: any) => {
    const [revision, setRevision] = useState<number>(0)

    useImperativeHandle(ref, () => ({
        recreate: () => {
            console.log("recreating scene")
            setRevision(prev => prev + 1)
        },
    }));

    return (
        <ViroScene key={revision}>
            {/* <ViroCamera active position={[0, 5, 2]} rotation={[-60, 0, 0]} /> */}
            <ViroAmbientLight color="#FFFFFF" intensity={500} />
            <ViroBox></ViroBox>
        </ViroScene>
    )
});

5. Run the app on your device, and after it loads press the "reload" button

Result

app crashes with "EXC_BAD_ACCESS" at [_contentView removeFromSuperview];

// File: RCTViewComponentView.mm
...
- (void)setContentView:(UIView *)contentView
{
  if (_contentView) {
    [_contentView removeFromSuperview]; // here
  }
...

Notes:

• this also happens for inner Viro objects such as Viro3DObject.
• it happens more on real device, but often also on SImulator/ Mac (designed for iPad)
• It happens on version react-native 0.76, but I tried also 0.77 and 0.77.1 and still the same
• I tried on 0.78 rc 5 - and encountered a blocker (which I did not investigate) about old react element being rendered... so gave up on that release check