c9136ca90605bbe29f005f538b92ff96ca360a13 validation: fix issue with an interrupted -reindex (Martin Zumsande)
a2675897e2a499aacbd0183fdccf1401953e8de5 validation: Don't loop over all chainstates in LoadExternalBlock (Martin Zumsande)
Pull request description:
If a user interrupts a reindex while it is iterating over the block files, it will continue to reindex with the next node start (if the `-reindex` arg is dropped, otherwise it will start reindexing from scratch).
However, due to an early call to `ActivateBestChainState()` that only exists to connect the genesis block during
the original `-reindex`, it wil start connecting blocks immediately before having iterated through all block files.
Because later headers above the minchainwork threshold won't be loaded in this case, `-assumevalid` will not
be applied and the process is much slower due to script validation being done.
Fix this by only calling `ActivateBestChainState()` here if Genesis is not connected yet (equivalent to `ActiveHeight() == -1`).
Also simplify this spot by only doing this for the active chainstate instead of looping over all chainstates (first commit).
This issue was discussed in the thread below https://github.com/bitcoin/bitcoin/pull/31346#discussion_r1856824817, the impact on assumevalid was found by l0rinc.
The fix can be tested by manually aborting a `-reindex` e.g. on signet and observing in the debug log the order in which blockfiles are indexed / blocks are connected with this branch vs master.
ACKs for top commit:
achow101:
ACK c9136ca90605bbe29f005f538b92ff96ca360a13
ryanofsky:
Code review ACK c9136ca90605bbe29f005f538b92ff96ca360a13. Only comments changed since last review. Appreciate the new comments, I think they make a little clearer what things code is trying to do and what things are just side-effects.
TheCharlatan:
Re-ACK c9136ca90605bbe29f005f538b92ff96ca360a13
Tree-SHA512: 6f34abc317ad7e605ccc0c2f4615e4ea6978223d207f80f768f39cc135a9ac0adf31681fadfa2aed45324a5d27a4f68c5e118ee7eec18ca5c40ef177caa9cc47
504d0c21e2