854a6d5a9a
The removal of the chain tip from setBlockIndexCandidates was happening after nSequenceId was modified. Since the set uses nSequenceId as a sort key, modifying it while the element is in the set is undefined behavior, which can cause the erase to fail. With assumeutxo, a second form of UB exists: two chainstates each have their own candidate set, but share the same CBlockIndex objects. Calling LoadChainTip on one chainstate mutates nSequenceIds that are also in the other chainstate's set. Fix by populating setBlockIndexCandidates after all changes to nSequenceId.
src/node/
The src/node/ directory contains code that needs to access node state
(state in CChain, CBlockIndex, CCoinsView, CTxMemPool, and similar
classes).
Code in src/node/ is meant to be segregated from code in
src/wallet/ and src/qt/, to ensure wallet and GUI
code changes don't interfere with node operation, to allow wallet and GUI code
to run in separate processes, and to perhaps eventually allow wallet and GUI
code to be maintained in separate source repositories.
As a rule of thumb, code in one of the src/node/,
src/wallet/, or src/qt/ directories should avoid
calling code in the other directories directly, and only invoke it indirectly
through the more limited src/interfaces/ classes.
This directory is at the moment
sparsely populated. Eventually more substantial files like
src/validation.cpp and
src/txmempool.cpp might be moved there.