Merge #11580: Do not send (potentially) invalid headers in response to getheaders
725b79a [test] Verify node doesn't send headers that haven't been fully validated (Russell Yanofsky)
3788a84 Do not send (potentially) invalid headers in response to getheaders (Matt Corallo)
Pull request description:
Nowhere else in the protocol do we send headers which are for
blocks we have not fully validated except in response to getheaders
messages with a null locator. On my public node I have not seen any
such request (whether for an invalid block or not) in at least two
years of debug.log output, indicating that this should have minimal
impact.
Tree-SHA512: c1f6e0cdcdfb78ea577d555f9b3ceb1b4b60eff4f6cf313bfd8b576c9562d797bea73abc23f7011f249ae36dd539c715f3d20487ac03ace60e84e1b77c0c1e1a