lazy/Suspense causing re-rendering to break application

Performing a re-render inside a lazy loaded component causes a TypeError. This does not happen with React’s Suspense.

The error can be reproduced with the current version of Preact. The problem does not exist in the 10.0.5 version.

It seems that the problem can be related with Suspense not setting the children pointer correctly. This was addressed in the commit b0fe5e7, but with the change to version 10.1.X it was lost.

Reproduction

Codesandbox that reproduces the error in Preact: https://codesandbox.io/s/compassionate-bell-t0vww

Same codesandbox working in React: https://codesandbox.io/s/white-hooks-cdj8q

Steps to reproduce

Render an element inside a lazy loaded component and force a re-render. In the sandbox there is a hook that calls setState the first time the element is loaded.

Expected Behavior

The component should be re-rendered the first time setState is called and then continue to work normally.

Actual Behavior

An error is thrown:

TypeError: Cannot set property ‘0’ of null

[olabala]

@marvinhagemeister thank u so much 🤝

[marvinhagemeister]

@olabala We’ve just published 10.4.6 🎉