bitcoin/bitcoin — pull request #5270 by domob1812 (2014-11-13 08:46:14+00:00)
Title: Check block header when accepting headers from peers.

Actually check block headers received from peers. If a peer sends headers with invalid PoW, they were accepted and added to the disk block index previously. This would then lead to a failure in checking the PoW
during the next startup while loading the block index.

This is a better version of https://github.com/bitcoin/bitcoin/pull/5269.