From d0bcb8106a89918d44476ba37b2fe7b93053ad5e Mon Sep 17 00:00:00 2001
From: Bohdan Triapitsyn <artmore@protonmail.com>
Date: Sun, 12 Jul 2026 00:44:58 +0300
Subject: [PATCH] fix(sync): preserve optimistic entries for stale loads

---
 packages/ui/src/sync/use-sync.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/ui/src/sync/use-sync.ts b/packages/ui/src/sync/use-sync.ts
index a53ebd69..9abdd76b 100644
--- a/packages/ui/src/sync/use-sync.ts
+++ b/packages/ui/src/sync/use-sync.ts
@@ -360,16 +360,16 @@ export function useSync() {
           mode: "replace" | "prepend" | undefined,
           isStale?: () => boolean,
         ) => {
+          if (isStale?.()) {
+            return { messages: [], cursor: page.cursor, complete: page.complete }
+          }
+
           const items = getOptimistic(sessionID)
           const merged = mergeOptimisticPage(page, items)
           for (const messageID of merged.confirmed) {
             clearOptimistic(sessionID, messageID)
           }
 
-          if (isStale?.()) {
-            return { messages: [], cursor: merged.cursor, complete: merged.complete }
-          }
-
           const current = store.getState()
           const materialized = materializeSessionSnapshots(
             current,