Icarus is not actually fast enough to run into this issue in a
reasonable amount of time. I discovered this by thinking about
the algorithm and verified the fix with custom code.
(cherry picked from commit 35488ac254)
After some more thought I believe it is better for $q_full to return
'bx instead of 2 when $q_full is given an invalid id. This will make
the typical full/not full checks both return false. We still return
an error code in the status variable.
(cherry picked from commit 10b2310c52)
Cary R