This commit adds info level log statements when a block causes a chain
fork, extends a side chain (fork), or causes a reorganize. When a reorg
happens, the new and old chain heads along with the fork point are logged.
Even though the code currently makes heavy use of nodes which will have
the appropriate height, blocks which did not come from the database will
not have a height set. As a result, this could possibly result in a
height of 0 being used when unintended. By setting the block height in
the block as soon as its known (regardless of the source), we can future
proof against bugs that would likely be hard to track down.
The btcscript API for GetSigOpCount and GetPreciseSigOpCount
recently changed to no longer return an error. This change was necessary
to mirror the behavior of bitcoind signature operations counting. This
commit modifies the code accordingly to use the new API.
It is acceptable for a transaction input in a block to reference the
output of another transaction in the same block only if the referenced
transaction comes before the transaction referencing it.
This commit modifies the double spend detection to handle double spends
within the same block as well as side chains when doing the checks before
reorganizing the chain.
In addition to returning errors to the caller, log the error with a prefix
in a few key places that helps identify the origin for errors. In some
cases, the underlying error comes from a different subsystem such as the
SQL database driver and the error messages can be fairly generic.
This commit modifies the code to use params based on the active network
which paves the way for supporting the special rules and different genesis
blocks used by the test networks.
After discussing the criteria used by the core developers on #btc-dev IRC
channel, gmaxwell indicated they like to see at least 2016 blocks. This
commit updates the checkpoint confirmations accordingly.
