This fixes ``Assertion `m_node.chainman' failed`` errors first reported
https://github.com/bitcoin/bitcoin/issues/33994#issuecomment-3602551596 when
IPC mining methods are called before ChainstateManager is loaded.
The fix works by making the `Init.makeMining` method block until chainstate
data is loaded.
At startup, if the needs to catch up, connected mining clients will
receive a flood of new templates as new blocks are connected.
Fix this by adding a cooldown argument to createNewBlock(). When set
to true, block template creation is briefly paused while the best
header chain is ahead of the tip.
This wait only happens when the best header extends the current tip,
to ignore competing branches.
Additionally, cooldown waits for isInitialBlockDownload() to latch to
false, which happens when there is less than a day of blocks left to sync.
When cooldown is false createNewBlock() returns immediately. The argument
is optional, because many tests are negatively impacted by this
mechanism, and single miner signets could end up stuck if no block
was mined for a day.
The getblocktemplate RPC also opts out, because it would add a delay
to each call.
Fixes#33994
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>
