ssu_error_.pl1 signals active_function_error condition for messages when code = 0

[Gary Dixon]

ssu_error_.pl1 provides entry points for ssu_$print_message, ssu_$abort_line and ssu_$abort_subsystem. For a standalone ssu_ invocation, it calls either com_err_ or active_fnc_err_ to display the message with error code. However, active_fnc_err_ signals the active_function_error condition to notify the caller that an error occurred; if the caller returns from handling that condition, then the error condition is displayed on the error_output switch. This happens even if the code parameter is 0.

Documentation for ssu_$print_message and the other entry points says:

If the code is zero, the "Code message" portion of the formatted output is omitted.

That leads the reader to believe that ssu_$print_message becomes a call to ioa_ when code = 0. But the code just calls com_err_ or active_fnc_err_ with a zero value. And active_fnc_err_ signals this spurious active_function_error every time it is called.

This is a defect which should be corrected by avoiding the call to com_err_ or active_fnc_err_ when code = 0.
Instead, the remaining message should be reported via ioa_$ioa_switch on the iox_$error_output switch.

[Eric Swenson]

​https://s3.amazonaws.com/eswenson-multics/public/mcrs/MCR10162.pdf

Fixed in MR12.9-1037.