fa8489a155 test: Add test for BIP30 duplicate tx (MarcoFalke)
77770d95e2 test: Properly serialize BIP34 coinbase height (MarcoFalke)
Pull request description:
This adds a test for BIP30 to check that duplicate txs can exist in the blockchain given the first one was completely spent when the second one is added. (Requested by ajtowns in https://github.com/bitcoin/bitcoin/pull/16333#issuecomment-508604071)
We can not add a test that a later duplicate tx overwrites a previous one, because BIP30 is always enforced on regtest. If someone feels strongly about such a test, some Bitcoin Core code would have to be modified, which can be done in a follow up pull request.
Also, add a commit to fix the BIP34 test failures reported in https://github.com/bitcoin/bitcoin/pull/14633#issue-227712540
ACKs for top commit:
laanwj:
Code review ACK fa8489a155
Tree-SHA512: c707d0bdc93937263876b603425b53322a2a9f9ec3f50716ae2fa9de8ddc644beb22b26c1bfde7f4aab102633e096b354ef380db919176bd2cb44a2828f884aa