solv_vercmp
r = solv_vercmp(evr1, s1, evr2, s2);
r = solv_vercmp(evr1, r1 ? r1 : s1, evr2, r2 ? r2 : s2);
r = solv_vercmp(r1, d1 ? d1 : s1, r2, d2 ? d2 : s2);
r = solv_vercmp(d1 + 1, s1, d2 + 1, s2);
r = solv_vercmp(r1, s1, r2, s2);
r = solv_vercmp(evr1, s1, epoch, epoch + strlen(epoch));
r = solv_vercmp(evr1, r1 ? r1 : s1, version, version + strlen(version));
r = solv_vercmp(r1 + 1, s1, release, release + strlen(release));
extern int solv_vercmp(const char *s1, const char *q1, const char *s2, const char *q2);