Missing wait for 0 ns in else-branch in WaitForLevel procedure

[Paebbels]

The WaitForLevel procedures have no else-branch with a delta-cycle delay in it.

If a WaitForLevel is used to also update signal assignments when the next wait statement is reached, it's not guaranteed by the implementation that all execution paths will cause an assignment.

Suggested solution:

if ... then
  -- wait until ...
else
  wait for 0 ns;
end if;

[JimLewis]

Can you share a use model?

[Paebbels]

dut_input <= '1';
WaitForLevel(dut_output);

dut_input <= '0';
wait until dut_error = '1';

This might never assign dut_input, because WaitForLevel doesn't always wait, but a user expects a wait procedure to behave like a wait statement. (That's the intension of a wait procedure, to abstract wait statements, right?)