policy_illegal_vendorchange
if (is->vendor != s->vendor && policy_illegal_vendorchange(solv, is, s))
if (!allowvendorchange && s->vendor != ps->vendor && policy_illegal_vendorchange(solv, s, ps))
if (!allowvendorchange && s->vendor != ps->vendor && policy_illegal_vendorchange(solv, s, ps))
extern int policy_illegal_vendorchange(Solver *solv, Solvable *s1, Solvable *s2);