I submitted a candidate fix patch for
bug 2132, I attached it to the bug report in Mantis.
I made it so that it simply displays an error message when the cargo limit is exceeded, and then sets the cargo name to blank (z=-1). I wasn't sure whether that was the best approach, or if I should set it to z=0, "Nothing"?
The other thing is that in the patch I added a neat little utility macro I use all the time, to help make the error message more friendly by including the value of MAX_CARGO. Is there a better place for little utility macros and helper functions such as this?