Add the comment about checking "AppVersion" in "verifyApp"

statesync/syncer.go

@@ -489,6 +489,8 @@ func (s *syncer) requestChunk(snapshot *snapshot, chunk uint32) {
 
 // verifyApp verifies the sync, checking the app hash, last block height and app version
 func (s *syncer) verifyApp(snapshot *snapshot, appVersion uint64) error {
+	// XXX Is it okay to check with "ABCI.Info" only
+	// since AppVersion will be updated by "ABCI.InitChain" and "ABCI.EndBlock"?
 	resp, err := s.connQuery.InfoSync(proxy.RequestInfo)
 	if err != nil {
 		return fmt.Errorf("failed to query ABCI app for appHash: %w", err)
@@ -497,7 +499,7 @@ func (s *syncer) verifyApp(snapshot *snapshot, appVersion uint64) error {
 	// sanity check that the app version in the block matches the application's own record
 	// of its version
 	if resp.AppVersion != appVersion {
-		// An error here most likely means that the app hasn't inplemented state sync
+		// An error here most likely means that the app hasn't implemented state sync
 		// or the Info call correctly
 		return fmt.Errorf("app version mismatch. Expected: %d, got: %d",
 			appVersion, resp.AppVersion)