rename pay_parameters for no amount invoice

This commit renames the function
pay_parameters_for_zero_amount_invoice to
pay_parameters_for_any_amount_invoice.

The reason for using the "any amount" naming convention
is to reflect basic English language usage and align with
other implementation naming conventions like [1].

Additionally, the term "any amount invoice" is also mentioned
in the BOLT11 specification [2].

There was a previous attempt to rename the function
to amount-less, but in my opinion, "any amount" is a more
common naming convention.

[1] https://github.com/ElementsProject/lightning/blob/b327bd30c32c034a8350460066b9e7354bfa4ba1/doc/schemas/lightning-invoice.json#L17
[2] https://github.com/lightning/bolts/blob/247e83d528a2a380e533e89f31918d7b0ce6a0c1/11-payment-encoding.md#examples
Fixes: #2879
Replaces: #2979
Signed-off-by: Vincenzo Palazzo <[email protected]>

Author: vincenzopalazzo

lightning/src/ln/bolt11_payment.rs

@@ -28,7 +28,7 @@ use crate::types::payment::PaymentHash;
 ///
 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 /// [`ChannelManager::send_preflight_probes`]: crate::ln::channelmanager::ChannelManager::send_preflight_probes
-pub fn payment_parameters_from_zero_amount_invoice(
+pub fn payment_parameters_from_any_amount_invoice(
 	invoice: &Bolt11Invoice, amount_msat: u64,
 ) -> Result<(PaymentHash, RecipientOnionFields, RouteParameters), ()> {
 	if invoice.amount_milli_satoshis().is_some() {
@@ -45,7 +45,7 @@ pub fn payment_parameters_from_zero_amount_invoice(
 /// same [`PaymentHash`] has never been paid before.
 ///
 /// Will always succeed unless the invoice has no amount specified, in which case
-/// [`payment_parameters_from_zero_amount_invoice`] should be used.
+/// [`payment_parameters_from_any_amount_invoice`] should be used.
 ///
 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 /// [`ChannelManager::send_preflight_probes`]: crate::ln::channelmanager::ChannelManager::send_preflight_probes
@@ -112,7 +112,7 @@ mod tests {
 			.build_signed(|hash| secp_ctx.sign_ecdsa_recoverable(hash, &private_key))
 			.unwrap();
 
-		assert!(payment_parameters_from_zero_amount_invoice(&invoice, 42).is_err());
+		assert!(payment_parameters_from_any_amount_invoice(&invoice, 42).is_err());
 
 		let (hash, onion, params) = payment_parameters_from_invoice(&invoice).unwrap();
 		assert_eq!(&hash.0[..], &payment_hash[..]);
@@ -146,7 +146,7 @@ mod tests {
 		assert!(payment_parameters_from_invoice(&invoice).is_err());
 
 		let (hash, onion, params) =
-			payment_parameters_from_zero_amount_invoice(&invoice, 42).unwrap();
+			payment_parameters_from_any_amount_invoice(&invoice, 42).unwrap();
 		assert_eq!(&hash.0[..], &payment_hash[..]);
 		assert_eq!(onion.payment_secret, Some(PaymentSecret([0; 32])));
 		assert_eq!(params.final_value_msat, 42);