zmailer getpw* routines

[Guy Middleton <gamiddleton@math.waterloo.edu>]

In lib/pwdgrp.c, it says:

/*
 * We implement getpwnam(), getpwuid(), and getgrnam() using the primitive
 * iteration functions (*ent()), in order to avoid constant allocations and
 * frees of fgets() buffers when the normal *nam() routines clean up after
 * finding what they're looking for.  This will lose if we're using a database
 * with slow iteration, but that can be handled elsewhere.
 */

Is it really "handled elsewhere"?  This looks like a classic time/space
tradeoff, but we can afford neither the time nor the space.