Merge pull request #5278 from overleaf/ab-analytics-id-old-sessions-fix

Backfill analyticsId for old sessions

GitOrigin-RevId: daecec07cf3cf0d40cab8c875528f7ebd667bd8b

services/web/app/src/Features/Analytics/AnalyticsManager.js

@@ -212,7 +212,7 @@ async function analyticsIdMiddleware(req, res, next) {
     }
   } else {
     if (sessionUser) {
-      session.analyticsId = sessionUser.analyticsId
+      session.analyticsId = sessionUser.analyticsId || sessionUser.userId // backfill for logged-in sessions created before we added the analyticsId
     } else {
       session.analyticsId = uuid.v4()
     }