Function LastCommonAncestor

src/chain.cpp:190–205

Find the last common ancestor two blocks have. * Both pa and pb must be non-nullptr. */

/** Find the last common ancestor two blocks have.
 *  Both pa and pb must be non-nullptr. */
const CBlockIndex* LastCommonAncestor(const CBlockIndex* pa, const CBlockIndex* pb) {
    if (pa->nHeight > pb->nHeight) {
        pa = pa->GetAncestor(pb->nHeight);
    } else if (pb->nHeight > pa->nHeight) {
        pb = pb->GetAncestor(pa->nHeight);
    }

    while (pa != pb && pa && pb) {
        pa = pa->pprev;
        pb = pb->pprev;
    }

    // Eventually all chain branches meet at the genesis block.
    assert(pa == pb);
    return pa;
}