Merge bitcoin/bitcoin#30624: doc: Remove outdated nTx faking comment

fa04511 doc: Remove outdated nTx faking comment (MarcoFalke)

Pull request description:

  This problematic  `nTx` "faking" was removed in commit b50554b.

  So fix the wrong comment.

  Also, address the typo nits from:

  * bitcoin/bitcoin#29370 (comment)
  * bitcoin/bitcoin#30598 (comment)

ACKs for top commit:
  fjahr:
    ACK fa04511

Tree-SHA512: c918f0b9274be9c347a37d6221915688977a858fb8d2146035718bf17df0bd3b51d67ef12b971556851c0f69f46d26f557c35a5461abeb0683b538b9dc48f5b6

Author: fanquake

src/validation.cpp

@@ -5399,7 +5399,7 @@ void ChainstateManager::CheckBlockIndex()
                     // and the transactions were not pruned (pindexFirstMissing
                     // is null), it is a potential candidate. The check
                     // excludes pruned blocks, because if any blocks were
-                    // pruned between pindex the current chain tip, pindex will
+                    // pruned between pindex and the current chain tip, pindex will
                     // only temporarily be added to setBlockIndexCandidates,
                     // before being moved to m_blocks_unlinked. This check
                     // could be improved to verify that if all blocks between

src/validation.h

@@ -1094,8 +1094,7 @@ class ChainstateManager
     //! - Verify that the hash of the resulting coinsdb matches the expected hash
     //!   per assumeutxo chain parameters.
     //! - Wait for our headers chain to include the base block of the snapshot.
-    //! - "Fast forward" the tip of the new chainstate to the base of the snapshot,
-    //!   faking nTx* block index data along the way.
+    //! - "Fast forward" the tip of the new chainstate to the base of the snapshot.
     //! - Move the new chainstate to `m_snapshot_chainstate` and make it our
     //!   ChainstateActive().
     [[nodiscard]] util::Result<CBlockIndex*> ActivateSnapshot(

test/functional/feature_assumeutxo.py

@@ -96,8 +96,6 @@ def expected_error(msg):
         self.log.info("  - snapshot file referring to a block that is not in the assumeutxo parameters")
         prev_block_hash = self.nodes[0].getblockhash(SNAPSHOT_BASE_HEIGHT - 1)
         bogus_block_hash = "0" * 64  # Represents any unknown block hash
-        # The height is not used for anything critical currently, so we just
-        # confirm the manipulation in the error message
         for bad_block_hash in [bogus_block_hash, prev_block_hash]:
             with open(bad_snapshot_path, 'wb') as f:
                 f.write(valid_snapshot_contents[:11] + bytes.fromhex(bad_block_hash)[::-1] + valid_snapshot_contents[43:])