After starting from command line bitocoind, it can require minutes to have bitocoind to be real responsive, for example:
`$ ./bitcoin-cli stop`
`error: {"code":-28,"message":"Activating best chain..."}`

In such situation, I had sometimes to "kill -9" bitcoind to stop it.
I would like to be able to stop bitcoind in clean way.

p.s.:
`$ uname -a`
`Darwin isghe.local 14.4.0 Darwin Kernel Version 14.4.0: Thu May 28 11:35:04 PDT 2015; root:xnu-2782.30.5~1/RELEASE_X86_64 x86_64`

std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin();
    while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, chainActive.Tip())) {
        setBlockIndexCandidates.erase(it++);
    }
    
    assert(!setBlockIndexCandidates.empty());
}
/**
 * Try to make some progress towards making pindexMostWork the active block.
 * pblock is either NULL or a pointer to a CBlock corresponding to pindexMostWork.
 */
static bool ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const CBlock* pblock)