Question: Why `propagateContextChanges` not restore the `workInProgress.child.return` pointer?

<!-- Ask a question or share feedback about the React 18 release here. --> This is the code from `ReactFiberNewContext.old.js` https://github.com/facebook/react/blob/19092ac8c354b92c2e0e27b73f391571ad452505/packages/react-reconciler/src/ReactFiberNewContext.old.js#L319-L333 In the function `propagateContextChanges` and `propagateContextChange_eager`, the `workInProgress.child.return` is changed in the beginning, but it is not restore in the end. In case of `propagateContextChanges`: ```js function propagateContextChanges<T>( workInProgress: Fiber, contexts: Array<any>, renderLanes: Lanes, forcePropagateEntireTree: boolean, ): void { // Only used by lazy implemenation if (!enableLazyContextPropagation) { return; } let fiber = workInProgress.child; if (fiber !== null) { // caution: before next line , fiber.return is workInProgress.alternate fiber.return = workInProgress; // after this line, fiber.return = workInProgress } // ... omit the other code // but in the end, there is no code to restore the workInProgress.child.return // maybe like this: workInProgress.child.return = workInProgress.alternate; } ``` I think the `workInProgress.child` is same as `workInProgress.alternate.child` at this time. If the `workInProgress.child.return` not restore, though the `workInProgress tree` is no difference , but maybe the `current tree` is broken? I'm confused about it some days, could anyone explain it?