Previously the coinbase transaction generated by our miner code was
not used downstream, because the getblocktemplate RPC excludes it.
Since the Mining IPC interface was introduced in #30200 we do expose
this dummy coinbase transaction. In Stratum v2 several parts of it
are communicated downstream, including the scriptSig.
This commit removes the dummy extraNonce from the coinbase scriptSig
in block templates requested via IPC. This limits the scriptSig
to what is essential for consensus (BIP34) and removes the need for
external mining software to remove the dummy, or even ignore
the scriptSig we provide and generate it some other way. This
could cause problems if a future soft fork requires additional
data to be committed here.
A test is added to verify the new IPC behavior.
It achieves this by introducing an include_dummy_extranonce
option which defaults to false with all test code updated to
set it to true. Because this option is not exposed via IPC,
callers will no longer see it.
The caller needs to ensure that for blocks 1 through 16
they pad the scriptSig in order to avoid bad-cb-length.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
This makes the options argument for BlockAssembler constructor mandatory,
dropping implicit use of ArgsManager. The caller i.e. the Mining
interface implementation now handles this.
In a future Stratum v2 change the Options object needs to be
mofified after arguments have been processed. Specifically
the pool communicates how many extra bytes it needs for
its own outputs (payouts, extra commitments, etc). This will need
to be substracted from what the user set as -blockmaxweight.
Such a change can be implemented in createNewBlock, after
ApplyArgsManOptions.
