f Split cltv_expiry_delta default and minimum and walk back 6*12 test change

Author: TheBlueMatt

lightning/src/ln/functional_tests.rs

@@ -2966,11 +2966,7 @@ fn test_htlc_on_chain_timeout() {
 
 	let chanmon_cfgs = create_chanmon_cfgs(3);
 	let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
-	let mut cfg = UserConfig::default();
-	// This test was written when the CLTV_EXPIRY_DELTA was fixed at 12*6, and expects it.
-	cfg.channel_options.cltv_expiry_delta = 12*6;
-	cfg.channel_options.announced_channel = true;
-	let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[Some(cfg.clone()), Some(cfg.clone()), Some(cfg.clone())]);
+	let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 	let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 
 	// Create some intial channels

lightning/src/util/config.rs

@@ -10,7 +10,7 @@
 //! Various user-configurable channel limits and settings which ChannelManager
 //! applies for you.
 
-use ln::channelmanager::{BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
 
 /// Configuration we set when applicable.
 ///
@@ -172,10 +172,14 @@ pub struct ChannelConfig {
 	/// Thus, for HTLC-encumbered balances to be enforced on-chain when a channel is force-closed,
 	/// we (or one of our watchtowers) MUST be online to check for broadcast of the current
 	/// commitment transaction at least once per this many blocks (plus some margin to allow us
-	/// enough time to broadcast and confirm a transaction).
+	/// enough time to broadcast and confirm a transaction, possibly with time in between to RBF
+	/// the spending transaction).
 	///
-	/// Default value: [`MIN_CLTV_EXPIRY_DELTA`], which we enforce as a minimum so you can change
-	/// the config to ask for more security, not less.
+	/// Default value: 72 (12 hours at an average of 6 blocks/hour).
+	/// Minimum value: [`MIN_CLTV_EXPIRY_DELTA`], any values less than this will be treated as
+	///                [`MIN_CLTV_EXPIRY_DELTA`] instead.
+	///
+	/// [`MIN_CLTV_EXPIRY_DELTA`]: ln::channelmanager::MIN_CLTV_EXPIRY_DELTA
 	pub cltv_expiry_delta: u16,
 	/// Set to announce the channel publicly and notify all nodes that they can route via this
 	/// channel.
@@ -208,7 +212,7 @@ impl Default for ChannelConfig {
 	fn default() -> Self {
 		ChannelConfig {
 			fee_proportional_millionths: 0,
-			cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
+			cltv_expiry_delta: 6 * 12, // 6 blocks/hour * 12 hours
 			announced_channel: false,
 			commit_upfront_shutdown_pubkey: true,
 		}