Enforce block connection ordering in unit and functional tests

This expands the assertions on block ordering to apply to
`#[cfg(test)]` builds in addition to normal builds, requiring that
unit and functional tests have syntactically-valid (ie the previous
block hash pointer and the heights match the blocks) blockchains.

This requires a reasonably nontrivial diff in the functional tests
however it is mostly straightforward changes.

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -3262,16 +3262,10 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
 		let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
 
-
-		// This assertion should be enforced in tests, however we have a number of tests that
-		// were written before this requirement and do not meet it.
-		#[cfg(not(test))]
-		{
-			assert_eq!(*self.last_block_hash.read().unwrap(), header.prev_blockhash,
-				"Blocks must be connected in chain-order - the connected header must build on the last connected header");
-			assert_eq!(self.latest_block_height.load(Ordering::Acquire) as u64, height as u64 - 1,
-				"Blocks must be connected in chain-order - the connected header must build on the last connected header");
-		}
+		assert_eq!(*self.last_block_hash.read().unwrap(), header.prev_blockhash,
+			"Blocks must be connected in chain-order - the connected header must build on the last connected header");
+		assert_eq!(self.latest_block_height.load(Ordering::Acquire) as u64, height as u64 - 1,
+			"Blocks must be connected in chain-order - the connected header must build on the last connected header");
 		self.latest_block_height.store(height as usize, Ordering::Release);
 		*self.last_block_hash.write().unwrap() = block_hash;
 

lightning/src/ln/functional_test_utils.rs

@@ -47,21 +47,8 @@ use std::collections::HashMap;
 pub const CHAN_CONFIRM_DEPTH: u32 = 10;
 
 pub fn confirm_transaction<'a, 'b, 'c, 'd>(node: &'a Node<'b, 'c, 'd>, tx: &Transaction) {
-	let starting_block = node.best_block_info();
-	let mut block = Block {
-		header: BlockHeader { version: 0x20000000, prev_blockhash: starting_block.0, merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
-		txdata: Vec::new(),
-	};
-	block.txdata.push(tx.clone());
-	let height = starting_block.1 + 1;
-	connect_block(node, &block, height);
-	for i in 2..CHAN_CONFIRM_DEPTH {
-		block = Block {
-			header: BlockHeader { version: 0x20000000, prev_blockhash: block.header.block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
-			txdata: vec![],
-		};
-		connect_block(node, &block, i + height);
-	}
+	confirm_transaction_at(node, tx, node.best_block_info().1 + 1);
+	connect_blocks(node, CHAN_CONFIRM_DEPTH - 1, node.best_block_info().1, false, Default::default());
 }
 pub fn confirm_transaction_at<'a, 'b, 'c, 'd>(node: &'a Node<'b, 'c, 'd>, tx: &Transaction, conf_height: u32) {
 	let starting_block = node.best_block_info();