From Martin Kaiser via bug 7312:

there's three coverity defects about division by zero in ui/cli/tap-iostat.c,
function iostat_packet()

This can be triggered from the command line

martin@greta# ./tshark -z io,stat,0.2,AVG\(frame.number\)
Capturing on eth0
Floating point exception

it->num is 0, wireshark crashes in

parent->max_vals[it->colnum] =                       
MAX(parent->max_vals[it->colnum], it->counter/it->num);

(and similar for other data types)

My proposal for a fix is to not update parent->max_vals[it->colnum] when
it->num==0, see the attached patch.

svn path=/trunk/; revision=42952

ui/cli/tap-iostat.c

@@ -467,6 +467,8 @@ iostat_packet(void *arg, packet_info *pinfo, epan_dissect_t *edt, const void *du
             }
             break;
         case CALC_TYPE_AVG:
+            if (it->num==0) /* avoid division by zero */
+               break;
             ftype=proto_registrar_get_ftype(it->hf_index);
             switch(ftype) {
                 case FT_FLOAT: