NOP1 through NOP10 are reserved for future soft-fork upgrades. When
such an upgrade occurs, the NOP argument will then require verification.
Rejecting transactions that contain these NOPs into the mempool will
discourage those transactions from being mined elsewhere and ensure
btcd will never mine such transactions. This prevents now
invalid scripts (according to the majority of hashing power) even if the
client has not yet upgraded.
Non-executed upgradable NOPs are still allowed as they will still be
valid post-upgrade.
Mimics Bitcoin Core commit 03914234b3c9c35d66b51d580fe727a0707394ca
This commit addes a couple of tests to ensure performing math operations
on a 5-byte integer, even if the result is a 4-byte integer, is considered
invalid.
Both the script tests (positive and negative) and tx texts (ditto) are
present. Some of the tx tests in the negative section have been
replaced by a comment line explaining why that test is elided, to add in
diffing. The reasons were always that they test things handled by other
parts of the btcd stack (normally chain). For example MAX_MONEY, number
of outputs, coinbase sizes etc.
Much of the inital test logic from @dajohi using hand transcribed tables
for selected tests. The json parsers, script format parser and a lot of
cleaning up/bugfixing from your truly. @davecgh had some input too.
