From 4639a572fec61bce53e0f67279e8ca1082da7e3e Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 15 Jan 2026 02:21:57 +0000
Subject: [PATCH] fix: prevent hashtag preferences reset on empty or stale
 relay responses

This commit updates `HashtagPreferencesService.load` to handle transient empty responses from relays more robustly.
- It prevents `reset()` if `wasLoadedForUser` is true and the fetch returns empty, ensuring existing data isn't wiped during connectivity issues or relay switches.
- It adds a staleness check to ignore incoming events that are older than the currently loaded data, protecting against out-of-sync relays returning obsolete preferences.

This addresses the issue where hashtag interests would disappear ("turn gray") or revert to older states shortly after login when video grid filters were applied.
---
 js/services/hashtagPreferencesService.js | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/js/services/hashtagPreferencesService.js b/js/services/hashtagPreferencesService.js
index 8ec9cc85..3ed72af4 100644
--- a/js/services/hashtagPreferencesService.js
+++ b/js/services/hashtagPreferencesService.js
@@ -430,9 +430,9 @@ class HashtagPreferencesService {
     if (!events.length) {
       // If we failed to fetch (network error) but already have data for this user,
       // preserve the existing state instead of wiping it.
-      if (fetchError && wasLoadedForUser) {
+      if (wasLoadedForUser) {
         userLogger.warn(
-          `${LOG_PREFIX} Keeping existing preferences after fetch error.`,
+          `${LOG_PREFIX} Keeping existing preferences despite empty relay response.`,
         );
         return;
       }
@@ -470,7 +470,7 @@ class HashtagPreferencesService {
     }, null);
 
     if (!latest) {
-      if (fetchError && wasLoadedForUser) {
+      if (wasLoadedForUser) {
         return;
       }
       this.reset();
@@ -478,6 +478,16 @@ class HashtagPreferencesService {
       return;
     }
 
+    const currentCreatedAt = Number(this.eventCreatedAt) || 0;
+    const latestCreatedAt = Number(latest.created_at) || 0;
+
+    if (wasLoadedForUser && currentCreatedAt > latestCreatedAt) {
+      userLogger.warn(
+        `${LOG_PREFIX} Ignoring stale preferences event (remote: ${latestCreatedAt}, local: ${currentCreatedAt}).`,
+      );
+      return;
+    }
+
     const decryptResult = await this.decryptEvent(latest, normalized);
     if (!decryptResult.ok) {
       userLogger.warn(