Just updated a node to current master (+https://github.com/bitcoin/bitcoin/pull/7685), the node ran successfully for a couple of weeks, shortly after updating to current master, I ran in a deadlock assertion:
I think the possible deadlock is not related to the PR which I'm running on top.

```
2016-08-26 07:50:29 POTENTIAL DEADLOCK DETECTED
2016-08-26 07:50:29 Previous lock order was:
2016-08-26 07:50:29  pnode->cs_vRecvMsg  net.cpp:1885 (TRY)
2016-08-26 07:50:29  cs_main  main.cpp:4726
2016-08-26 07:50:29  (1) pfrom->cs_filter  main.cpp:4784
2016-08-26 07:50:29  (2) cs_vSend  net.cpp:2683
2016-08-26 07:50:29 Current lock order is:
2016-08-26 07:50:29  (2) pnode->cs_vSend  net.cpp:1904 (TRY)
2016-08-26 07:50:29  cs_main  main.cpp:6343 (TRY)
2016-08-26 07:50:29  pto->cs_inventory  main.cpp:6563
2016-08-26 07:50:29  (1) pto->cs_filter  main.cpp:6586
```

AssertLockHeld(cs_main);
    int nHeight = pindex->nHeight;
    
    BlockMap::iterator it = mapBlockIndex.begin();
    while (it != mapBlockIndex.end()) {
        if (!it->second->IsValid() && it->second->GetAncestor(nHeight) == pindex) {
            it->second->nStatus &= ~BLOCK_FAILED_MASK;
            setDirtyBlockIndex.insert(it->second);
            if (it->second->IsValid(BLOCK_VALID_TRANSACTIONS) && it->second->nChainTx && setBlockIndexCandidates.value_comp()(chainActive.Tip(), it->second)) {
                setBlockIndexCandidates.insert(it->second);
            }
            if (it->second == pindexBestInvalid) {
                
                pindexBestInvalid = NULL;
            }
        }
        it++;
    }
    
    while (pindex != NULL) {
        if (pindex->nStatus & BLOCK_FAILED_MASK) {
            pindex->nStatus &= ~BLOCK_FAILED_MASK;
            setDirtyBlockIndex.insert(pindex);
        }
        pindex = pindex->pprev;
    }
    return true;
}
CBlockIndex* AddToBlockIndex(const CBlockHeader& block)