Extraneous output when error is cast as an integer.

[tavmem]

In a case where a function returns an integer, (so the error is cast as an integer), as in:

I KC(K a, K b)//List Compare (K Compare)  {
  if(b==NULL)R (I)TE;
  ...

Kona displays extraneous output line before the "type error" message:

$ rlwrap -n ~/kona/k
K Console - Enter \ for help
  >9,_9,`
0 1
type error
>9,_9,`
at execution instance 1 of ","
>  

[tavmem]

Re-opened by backout to fix #532