test: move SyncWithValidationInterfaceQueue() before Stop() in txindex_tests

So that the call order is the same as in coinstatsindex_tests.

src/test/txindex_tests.cpp

@@ -69,11 +69,16 @@ BOOST_FIXTURE_TEST_CASE(txindex_initial_sync, TestChain100Setup)
         }
     }
 
+    // It is not safe to stop and destroy the index until it finishes handling
+    // the last BlockConnected notification. The BlockUntilSyncedToCurrentChain()
+    // call above is sufficient to ensure this, but the
+    // SyncWithValidationInterfaceQueue() call below is also needed to ensure
+    // TSAN always sees the test thread waiting for the notification thread, and
+    // avoid potential false positive reports.
+    SyncWithValidationInterfaceQueue();
+
     // shutdown sequence (c.f. Shutdown() in init.cpp)
     txindex.Stop();
-
-    // Let scheduler events finish running to avoid accessing any memory related to txindex after it is destructed
-    SyncWithValidationInterfaceQueue();
 }
 
 BOOST_AUTO_TEST_SUITE_END()