Testing O2debugger found a bug (last progress version)
With this code the 2 last print are not executed. But if you change "print vshort" by "print str(vshort)" it works.
However in more complex cases it's not enough : more code add to be added.
% FileName "test.exe"
sub testsub(vshort as short)
print vshort
end sub
testsub(12)
print "after sub "
print "pgm exit"