Address CR comments

substrate/frame/beefy-mmr/src/lib.rs

@@ -258,17 +258,14 @@ where
 				},
 			};
 
+		let mut found_commitment_root = false;
 		let commitment_roots = commitment
 			.payload
 			.get_all_decoded::<MerkleRootOf<T>>(&known_payloads::MMR_ROOT_ID);
-		if commitment_roots.is_empty() {
-			// If the commitment doesn't contain any MMR root, while the proof is valid,
-			// the commitment is invalid
-			return true;
-		}
 		for maybe_commitment_root in commitment_roots {
 			match maybe_commitment_root {
 				Some(commitment_root) => {
+					found_commitment_root = true;
 					if canonical_prev_root != commitment_root {
 						// If the commitment contains an MMR root, that is not equal to
 						// `canonical_prev_root`, the commitment is invalid
@@ -281,6 +278,11 @@ where
 				},
 			}
 		}
+		if !found_commitment_root {
+			// If the commitment doesn't contain any MMR root, while the proof is valid,
+			// the commitment is invalid
+			return true;
+		}
 
 		false
 	}

substrate/primitives/consensus/beefy/src/payload.rs

@@ -57,11 +57,13 @@ impl Payload {
 	}
 
 	/// Returns all the raw payloads under given `id`.
-	pub fn get_all_raw(&self, id: &BeefyPayloadId) -> Vec<&Vec<u8>> {
+	pub fn get_all_raw<'a>(
+		&'a self,
+		id: &'a BeefyPayloadId,
+	) -> impl Iterator<Item = &Vec<u8>> + 'a {
 		self.0
 			.iter()
-			.filter_map(|probe| if &probe.0 != id { return None } else { Some(&probe.1) })
-			.collect()
+			.filter_map(move |probe| if &probe.0 != id { return None } else { Some(&probe.1) })
 	}
 
 	/// Returns a decoded payload value under given `id`.
@@ -72,8 +74,11 @@ impl Payload {
 	}
 
 	/// Returns all decoded payload values under given `id`.
-	pub fn get_all_decoded<T: Decode>(&self, id: &BeefyPayloadId) -> Vec<Option<T>> {
-		self.get_all_raw(id).iter().map(|raw| T::decode(&mut &raw[..]).ok()).collect()
+	pub fn get_all_decoded<'a, T: Decode>(
+		&'a self,
+		id: &'a BeefyPayloadId,
+	) -> impl Iterator<Item = Option<T>> + 'a {
+		self.get_all_raw(id).map(|raw| T::decode(&mut &raw[..]).ok())
 	}
 
 	/// Push a `Vec<u8>` with a given id into the payload vec.