reallocarray
void *reallocarray(void *, size_t, size_t);
ncs = reallocarray(p->g->sets, p->g->ncsets + 1, sizeof(*ncs));
newwides = reallocarray(cs->wides, cs->nwides + 1,
newranges = reallocarray(cs->ranges, cs->nranges + 1,
newtypes = reallocarray(cs->types, cs->ntypes + 1,
sp = reallocarray(p->strip, size, sizeof(*p->strip));
g->strip = reallocarray(p->strip, p->slen, sizeof(*p->strip));
void *reallocarray(void *, size_t, size_t);
p = reallocarray(d13, newsz, sizeof(struct diff));
p = reallocarray(d23, newsz, sizeof(struct diff));
p = reallocarray(de, newsz, sizeof(struct diff));
q = reallocarray(overlap, newsz, sizeof(char));
void *p = reallocarray(old, s1, s2);