f - Add missing test case

Author: jkczyz

lightning-invoice/src/lib.rs

@@ -1590,6 +1590,14 @@ mod test {
 		}.unwrap();
 		assert!(Invoice::from_signed(invoice).is_ok());
 
+		// No payment secret or feature bits
+		let invoice = {
+			let mut invoice = invoice_template.clone();
+			invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
+			invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
+		}.unwrap();
+		assert!(Invoice::from_signed(invoice).is_ok());
+
 		// Missing payment secret
 		let invoice = {
 			let mut invoice = invoice_template.clone();