Drop create_inbound_payment*_legacy breaking downgrade to 0.0.103

0.0.103 is now downright ancient, and certainly shouldn't exist in
production anywhere today. Thus, it seems fine to remove the
ability to create legacy stateful inbound payment entries.

Users downgrading to 0.0.103 will thus not be able to claim any
payments created on modern LDK, though we still retain the ability
to claim such payments at least for one more release.

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -5874,37 +5874,6 @@ where
 		}
 	}
 
-	fn set_payment_hash_secret_map(&self, payment_hash: PaymentHash, payment_preimage: Option<PaymentPreimage>, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32) -> Result<PaymentSecret, APIError> {
-		assert!(invoice_expiry_delta_secs <= 60*60*24*365); // Sadly bitcoin timestamps are u32s, so panic before 2106
-
-		if min_value_msat.is_some() && min_value_msat.unwrap() > MAX_VALUE_MSAT {
-			return Err(APIError::APIMisuseError { err: format!("min_value_msat of {} greater than total 21 million bitcoin supply", min_value_msat.unwrap()) });
-		}
-
-		let payment_secret = PaymentSecret(self.entropy_source.get_secure_random_bytes());
-
-		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-		let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
-		match payment_secrets.entry(payment_hash) {
-			hash_map::Entry::Vacant(e) => {
-				e.insert(PendingInboundPayment {
-					payment_secret, min_value_msat, payment_preimage,
-					user_payment_id: 0, // For compatibility with version 0.0.103 and earlier
-					// We assume that highest_seen_timestamp is pretty close to the current time -
-					// it's updated when we receive a new block with the maximum time we've seen in
-					// a header. It should never be more than two hours in the future.
-					// Thus, we add two hours here as a buffer to ensure we absolutely
-					// never fail a payment too early.
-					// Note that we assume that received blocks have reasonably up-to-date
-					// timestamps.
-					expiry_time: self.highest_seen_timestamp.load(Ordering::Acquire) as u64 + invoice_expiry_delta_secs as u64 + 7200,
-				});
-			},
-			hash_map::Entry::Occupied(_) => return Err(APIError::APIMisuseError { err: "Duplicate payment hash".to_owned() }),
-		}
-		Ok(payment_secret)
-	}
-
 	/// Gets a payment secret and payment hash for use in an invoice given to a third party wishing
 	/// to pay us.
 	///
@@ -5944,23 +5913,6 @@ where
 			min_final_cltv_expiry_delta)
 	}
 
-	/// Legacy version of [`create_inbound_payment`]. Use this method if you wish to share
-	/// serialized state with LDK node(s) running 0.0.103 and earlier.
-	///
-	/// May panic if `invoice_expiry_delta_secs` is greater than one year.
-	///
-	/// # Note
-	/// This method is deprecated and will be removed soon.
-	///
-	/// [`create_inbound_payment`]: Self::create_inbound_payment
-	#[deprecated]
-	pub fn create_inbound_payment_legacy(&self, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32) -> Result<(PaymentHash, PaymentSecret), APIError> {
-		let payment_preimage = PaymentPreimage(self.entropy_source.get_secure_random_bytes());
-		let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
-		let payment_secret = self.set_payment_hash_secret_map(payment_hash, Some(payment_preimage), min_value_msat, invoice_expiry_delta_secs)?;
-		Ok((payment_hash, payment_secret))
-	}
-
 	/// Gets a [`PaymentSecret`] for a given [`PaymentHash`], for which the payment preimage is
 	/// stored external to LDK.
 	///
@@ -6014,20 +5966,6 @@ where
 			min_final_cltv_expiry)
 	}
 
-	/// Legacy version of [`create_inbound_payment_for_hash`]. Use this method if you wish to share
-	/// serialized state with LDK node(s) running 0.0.103 and earlier.
-	///
-	/// May panic if `invoice_expiry_delta_secs` is greater than one year.
-	///
-	/// # Note
-	/// This method is deprecated and will be removed soon.
-	///
-	/// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
-	#[deprecated]
-	pub fn create_inbound_payment_for_hash_legacy(&self, payment_hash: PaymentHash, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32) -> Result<PaymentSecret, APIError> {
-		self.set_payment_hash_secret_map(payment_hash, None, min_value_msat, invoice_expiry_delta_secs)
-	}
-
 	/// Gets an LDK-generated payment preimage from a payment hash and payment secret that were
 	/// previously returned from [`create_inbound_payment`].
 	///

pending_changelog/no-legacy-payments.txt

@@ -0,0 +1,4 @@
+ * Legacy inbound payment creation has been removed, thus there is no way to
+   create a pending inbound payment which will still be claimable on LDK
+   0.0.103 or earlier. Support for claiming such payments is still retained,
+   however is likely to be removed in the next release.