LPRng printing broken

[jdreed]

jdreed@INFINITE-LOOP:~$ lpr -Pw20thesis
lpr: missing argument for 'm'
Usage: lpr [-Pprinter[@host]] [-A] [-B] [-Cclass] [-Fformat] [-G]
[-Jinfo]
   [-(K|#)copies] [-Q] [-Raccountname]  [-Ttitle]  [-Uuser[@host]] [-V]
   [-Zoptions] [-b] [-m mailaddr] [-h] [-i indent] [-l] [-w width ] [-r]
   [-Ddebugopt ] [--] [ filenames ...  ]

The problem is this block:

        if not zephyr_args and os.environ.get('ATHENA_USER'):
            if argstyle == common.SYSTEM_CUPS:
                options.append(('-m', ''))
            elif argstyle == common.SYSTEM_LPRNG:
                options.append(('-m', 'zephyr%' + os.environ['ATHENA_USER']))

An invocation like lpr -Pw20thesis counts as "CUPS argument style", and therefore gets -m appended to it. However, it's an LPRng queue, so that fails.

[jdreed]

Fixed in r24856-r24858. It now checks for LPRng argstyle, then checks the subsystem to see if it'll be invoking CUPS or LPRng.

I also added a unit test for this, but we should use the manual test suite this time as well.