verify(handle, times(1)).ensureTreeConnected();
    }

    @Test
    @DisplayName("ensureTreeConnected propagates CIFSException from handle")
    void ensureTreeConnected_propagatesException() throws Exception {
        // Arrange
        SmbPipeOutputStream out = newStream();
        CIFSException boom = new CIFSException("tree-fail");
        when(handle.ensureTreeConnected()).thenThrow(boom);