Hi,
Per Coverity.
If has 0 full groups, "we don't need to do anything" and need goes to next.
Otherwise a integer division by zero, can raise.
comments extracted trom explain.c:
/*
* Since we never have any prefix groups unless we've first sorted
* a full groups and transitioned modes (copying the tuples into a
* prefix group), we don't need to do anything if there were 0 full
* groups.
*/
regards,
Ranier Vilela