f - disallow Some(1) for quantity_max

Author: jkczyz

lightning/src/offers/offer.rs

@@ -431,8 +431,9 @@ pub enum Quantity {
 impl Quantity {
 	fn new(quantity: Option<u64>) -> Self {
 		match quantity {
-			Some(1) | None => Quantity::One,
+			None => Quantity::One,
 			Some(0) => Quantity::Many,
+			Some(1) => unreachable!(),
 			Some(n) => Quantity::Max(NonZeroU64::new(n).unwrap()),
 		}
 	}
@@ -515,7 +516,10 @@ impl TryFrom<OfferTlvStream> for OfferContents {
 			paths => paths,
 		};
 
-		let supported_quantity = Quantity::new(quantity_max);
+		let supported_quantity = match quantity_max {
+			Some(1) => return Err(SemanticError::InvalidQuantity),
+			_ => Quantity::new(quantity_max),
+		};
 
 		if node_id.is_none() {
 			return Err(SemanticError::MissingNodeId);

lightning/src/offers/parse.rs

@@ -80,6 +80,8 @@ pub enum SemanticError {
 	MissingNodeId,
 	/// An empty set of blinded paths was provided.
 	MissingPaths,
+	/// An unsupported quantity was provided.
+	InvalidQuantity,
 }
 
 impl From<bech32::Error> for ParseError {