Andrew Chow ab163b0fb5
Merge bitcoin/bitcoin#27823: init: return error when block index is non-contiguous, fix feature_init.py file perturbation
d27b9a2248476439ddab7700327f074005a810d5 test: fix feature_init.py file perturbation (Martin Zumsande)
ad66ca1e475d2546dbbda206465307613108a15d init: abort loading of blockindex in case of missing height. (Martin Zumsande)

Pull request description:

  When the block index database is non-contiguous due to file corruption (i.e. it contains indexes of height `x-1` and `x+1`, but not `x`), bitcoind can currently crash with an assert in `BuildSkip()` / `GetAncestor()` during `BlockManager::LoadBlockIndex()`:
  ```
  bitcoind: chain.cpp:112: const CBlockIndex* CBlockIndex::GetAncestor(int) const: Assertion `pindexWalk->pprev' failed.
  ```
  This PR changes it such that we instead return an `InitError` to the user.

  I stumbled upon this because I noticed that the file perturbation in `feature_init.py`  wasn't working as intended, which is fixed in the second commit:
  * Opening the file twice in one `with` statement would lead to `tf_read` being empty, so the test wouldn't perturb anything but replace the file with a new one. Fixed by first opening for read, then for write.
  * We need to restore the previous state after perturbations, so that only the current perturbation is active and not a mix of the current and previous ones.
  * I also added `checkblocks=200` to the startup parameters so that corruption in earlier blocks of `blk00000.dat` is detected during init verification and not ignored.

  After fixing `feature_init.py` like that I'd run into the `assert` mentioned above (so running the testfix from the second commit without the first one is a way to reproduce it).

ACKs for top commit:
  achow101:
    ACK d27b9a2248476439ddab7700327f074005a810d5
  furszy:
    Code ACK d27b9a224
  fjahr:
    Code review ACK d27b9a2248476439ddab7700327f074005a810d5

Tree-SHA512: 2e54da6030c5813c86bd58f816401e090bb43c5b834764a5e3c0e55dbfe09e423f88042cab823db3742088204b274d4ad2abf58a3832a4b18328b11a30bf7094
2023-10-04 15:36:57 -04:00
..
2023-05-20 12:03:22 +02:00
2023-08-05 10:42:56 +02:00

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.