(core) restore ActiveDoc shutdown behavior on error

Summary:
A recent change perturbed some error handling when an ActiveDoc
is shutting down. It is important that errors get thrown when
attempting to replace a non-existent document. My bad in review
for not catching.

Test Plan: Snapshot test passes again

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: georgegevoian, cyprien

Differential Revision: https://phab.getgrist.com/D3824

app/server/lib/ActiveDoc.ts

@@ -34,7 +34,7 @@ import {
   TransformRule
 } from 'app/common/ActiveDocAPI';
 import {ApiError} from 'app/common/ApiError';
-import {asyncOnce, mapGetOrSet, MapWithTTL} from 'app/common/AsyncCreate';
+import {mapGetOrSet, MapWithTTL} from 'app/common/AsyncCreate';
 import {AttachmentColumns, gatherAttachmentIds, getAttachmentColumns} from 'app/common/AttachmentColumns';
 import {
   BulkAddRecord,
@@ -231,10 +231,7 @@ export class ActiveDoc extends EventEmitter {
   private _recoveryMode: boolean = false;
   private _shuttingDown: boolean = false;
   private _afterShutdownCallback?: () => Promise<void>;
-  // catch & report error so that asyncOnce does not get cleared.
-  private _doShutdown = asyncOnce(
-    () => this._doShutdownImpl().catch((e) => log.error('Uncaught shutdown error', e))
-  );
+  private _doShutdown?: Promise<void>;
 
   /**
    * In cases where large numbers of documents are restarted simultaneously
@@ -501,10 +498,10 @@ export class ActiveDoc extends EventEmitter {
     if (options.afterShutdown) {
       this._afterShutdownCallback = options.afterShutdown;
     }
-    await this._doShutdown();
+    this._doShutdown ||= this._doShutdownImpl();
+    await this._doShutdown;
   }
 
-
   private async _doShutdownImpl(): Promise<void> {
     const docSession = makeExceptionalDocSession('system');
     this._log.debug(docSession, "shutdown starting");