- _nc_SPRINTF(my_buffer, _nc_SLIMIT(sizeof(my_buffer))
- TRACEMSE_FMT,
- ep->id,
- ep->x,
- ep->y,
- ep->z,
- (unsigned long) ep->bstate);
-
- (void) _trace_mmask_t(sp, ep->bstate);
- _nc_STRCAT(my_buffer, "}", sizeof(my_buffer));
- return (my_buffer);
+ char *result = 0;
+
+ if (sp != 0) {
+ _nc_SPRINTF(my_buffer, _nc_SLIMIT(sizeof(my_buffer))
+ TRACEMSE_FMT,
+ ep->id,
+ ep->x,
+ ep->y,
+ ep->z,
+ (unsigned long) ep->bstate);
+
+ (void) _nc_trace_mmask_t(sp, ep->bstate);
+ _nc_STRCAT(my_buffer, "}", sizeof(my_buffer));
+ result = (my_buffer);
+ }
+ return result;