fix(server): Don't inline schedule when in LOADING

Author: royjacobson

src/server/transaction.cc

@@ -689,7 +689,12 @@ OpStatus Transaction::ScheduleSingleHop(RunnableType cb) {
       }
     };
 
-    if (coordinator_index_ == unique_shard_id_) {
+    // We can't allow inline scheduling during a full sync, because then journaling transactions
+    // will be scheduled before RdbLoader::LoadItemsBuffer is finished. We can't use the regular
+    // locking mechanism because RdbLoader is not using transactions.
+    if (coordinator_index_ == unique_shard_id_ &&
+        ServerState::tlocal()->gstate() != GlobalState::LOADING) {
+      DVLOG(2) << "Inline scheduling a transaction";
       schedule_cb();
     } else {
       shard_set->Add(unique_shard_id_, std::move(schedule_cb));  // serves as a barrier.