Quartus_syn and nested pragma not supported

For instance take this code which compiles for both quartus_map✔& quartus_syn✔:

library ieee;
use ieee.std_logic_1164.all;

--altera translate_off
--altera translate_on
library altera_mf;  -- Example Altera-specific library
use altera_mf.altera_mf_components.all;
--altera translate_off
--altera translate_on

But that one compiles only on quartus_map✔ and fails on quartus_syn with "unexpected end-of-file" error:

library ieee;
use ieee.std_logic_1164.all;

--pragma translate_off
--altera translate_on
library altera_mf;  -- Example Altera-specific library
use altera_mf.altera_mf_components.all;
--altera translate_off
--pragma translate_on