If network offline or API error happens, the `session` returned by the `useSession` hook will be null, so we can't assume it is not null.
There should be following changes:
1. create a page in ErrorBoundary to let the user refetch the session.
2. The `SessionProvider` stop to pull the new session once the session is null, we need to figure out a way to pull the new session when the network is back or the user click the refetch button.
It seems there are some cases that [this upstream PR](https://github.com/toeverything/blocksuite/pull/4747) will cause data loss.
Because of some historical reasons, the page id could be different with its doc id.
It might be caused by subdoc migration in the following (not 100% sure if all white screen issue is caused by it) 0714c12703/packages/common/infra/src/blocksuite/index.ts (L538-L540)
In version 0.10, page id in spaces no longer has prefix "space:"
The data flow for fetching a doc's updates is:
- page id in `meta.pages` -> find `${page-id}` in `doc.spaces` -> `doc` -> `doc.guid`
if `doc` is not found in `doc.spaces`, a new doc will be created and its `doc.guid` is the same with its pageId
- because of guid logic change, the doc that previously prefixed with `space:` will not be found in `doc.spaces`
- when fetching the rows of this doc using the doc id === page id,
it will return EMPTY since there is no updates associated with the page id
The provided fix in the PR will patch the `spaces` field of the root doc so that after 0.10 the page doc can still be found in the `spaces` map. It shall apply to both of the idb & sqlite datasources.
Special thanks to @lawvs 's db file for investigation!
