Clean tmp accounts map when race gets duplicate

Added check to the test to ensure that tmp map is empty.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

server/norace_test.go

@@ -790,4 +790,18 @@ func TestNoRaceFetchAccountDoesNotRegisterAccountTwice(t *testing.T) {
 	if !ok {
 		t.Fatalf("B should be able to receive messages")
 	}
+
+	checkTmpAccounts := func(t *testing.T, s *Server) {
+		t.Helper()
+		empty := true
+		s.tmpAccounts.Range(func(_, _ interface{}) bool {
+			empty = false
+			return false
+		})
+		if !empty {
+			t.Fatalf("tmpAccounts is not empty")
+		}
+	}
+	checkTmpAccounts(t, sa)
+	checkTmpAccounts(t, sb)
 }

server/server.go

@@ -878,6 +878,7 @@ func (s *Server) registerAccountNoLock(acc *Account) *Account {
 	// We are under the server lock. Lookup from map, if present
 	// return existing account.
 	if a, _ := s.accounts.Load(acc.Name); a != nil {
+		s.tmpAccounts.Delete(acc.Name)
 		return a.(*Account)
 	}
 	// Finish account setup and store.