Mempool improvements, branch ID awareness
Whenever the local chain tip is updated, transactions in the mempool which commit to an
unmineable branch ID (for example, just before a network upgrade activates, where the
next block will have a different branch ID) will be removed.
Includes commits cherry-picked from the following upstream PRs:
- bitcoin/bitcoin#6654
- Only the mempool index change.
- bitcoin/bitcoin#6776
- bitcoin/bitcoin#7020
- bitcoin/bitcoin#6915
Part of #2074.
Add ability for node to reject tx from mempool by number of tx inputs
Implement short-term solution described in #2343 so that users can respond promptly to critical short-term problems caused by quadratic validation scaling, such as the getblocktemplate latency, block propagation latency, and mempool size inflation issues described in #2333.
Test prioritisetransaction
After talking with @str4d about #1884 , I wrote a test for prioritisetransaction. It uses small blocks (11kb), and checks whether a transaction makes it into the next block after being prioritized by that node.
Should this be improved with a larger number of txs in the mempool, or by testing over multiple runs?
As for getblocktemplate(), it seems to return the prioritized transaction within the block size set by the node (about 50 txs fit in an 11kb block), but the block "sizelimit" it displays is set at 2 MB in `rpcmining.cpp` line 690:
```
result.push_back(Pair("sizelimit", (int64_t)MAX_BLOCK_SIZE));
```
This was quite confusing, I didn't think the `-blockmaxsize` parameter I was setting was working for awhile.
Return a more informative error message when trying to spend coinbase; select non-coinbase inputs when sending to a transparent output if needed
For #1373 and #1519
Code change:
- Extra parameter added to AvailableCoins to include or exclude Coinbase coins. Default value of parameter is 'true' as current behaviour is to include Coinbase coins.
- SelectCoins, used for sending taddr->taddr, will now exclude Coinbase coins.
Unit test:
Tried to write a test to focus on the extra parameter added to AvailableCoins but could not.
Empirical testing on Testnet:
Current behaviour is that upstream RPC commands sendfrom and sendtoaddress try to spend coinbase coins returned by AvailableCoins. So the user will see:
```
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 1000.0
error: {"code":-6,"message":"Insufficient funds"}
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 0.00003000
error: {"code":-4,"message":"Error: The transaction was rejected! This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here."}
./zcash-cli sendfrom "" mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 0.00003000
error: {"code":-4,"message":"Error: The transaction was rejected! This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here."}
```
After fix is applied:
```
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 1000.0
error: {"code":-6,"message":"Insufficient funds"}
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 0.00003000
error: {"code":-4,"message":"Coinbase funds can only be sent to a zaddr"}
```
When non-coinbase UTXOs exist, they will now be selected and used:
```
./zcash-cli z_sendmany tnPJZHeVxegCg91utaquBRPEDBGjozfz9iLDHt7zvphFbZdspNgkTVLCGjDcadQBKNyUwKs8pNjDXuEZKrE1aNLpFwHgz4t '[{"address":"mx5fTRhLZwbYE7ZqhAPueZgQGSnwTbdvKU", "amount":0.01}]'
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 1000.0
error: {"code":-6,"message":"Insufficient funds"}
./zcash-cli sendtoaddress mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 0.00003000
9818e543ac2f689d4ce8b52087607d73fecd771d45d316a1d9db092f0485aff2
./zcash-cli sendfrom "" mrEGRmGJhmwAa4MQjzGd86ry63vrvovu9b 0.00003000
899f2894823f51f15fc73b5e0871ac943edbe0ff88e1635f86906087b72caf30
```
Extra parameter added to AvailableCoins to include or exclude Coinbase coins.
SelectCoins, used for sending taddr->taddr, will exclude Coinbase coins.
Added qa rpc test and a runtime parameter -regtestprotectcoinbase to enforce
the coinbase->zaddr consensus rule in regtest mode.
Daira Hopwood
James O'Beirne
Jack Grigg
Simon
Homu
Jay Graber
Matt Corallo
Nathan Wilcox
Wladimir J. van der Laan
Jonas Schnelli
mruddy
Cory Fields
Sean Bowe
zkbot
Taylor Hornby
Nathan Wilcox
Suhas Daftuar