modify for multiple double-voting in vetomint

vetomint/src/misbehavior.rs

@@ -8,6 +8,7 @@ pub(crate) fn check_double_prevote(
     state: &ConsensusState,
     target_round: Round,
 ) -> Vec<ConsensusResponse> {
+    let mut response = Vec::new();
     let mut validators_map = HashMap::new();
     let prevotes_in_target_round: Vec<_> = state
         .prevotes
@@ -21,29 +22,30 @@ pub(crate) fn check_double_prevote(
             .or_insert((0, vote.proposal));
         *count += 1;
 
-        if *count == 2 {
+        if *count >= 2 {
             let byzantine_validator = vote.signer;
             let double_proposal = vote.proposal;
 
-            return vec![ConsensusResponse::ViolationReport {
+            response.extend(vec![ConsensusResponse::ViolationReport {
                 violator: byzantine_validator,
                 misbehavior: Misbehavior::DoublePrevote {
                     byzantine_node: byzantine_validator,
                     round: target_round,
                     proposals: (*origin_proposal, double_proposal),
                 },
-            }];
+            }]);
         }
     }
 
-    Vec::new()
+    response
 }
 
 /// Check whether there are double precommits in target round
 pub(crate) fn check_double_precommit(
     state: &ConsensusState,
     target_round: Round,
 ) -> Vec<ConsensusResponse> {
+    let mut response = Vec::new();
     let mut validators_map = HashMap::new();
     let precommits_in_target_round: Vec<_> = state
         .precommits
@@ -57,20 +59,19 @@ pub(crate) fn check_double_precommit(
             .or_insert((0, vote.proposal));
         *count += 1;
 
-        if *count == 2 {
+        if *count >= 2 {
             let byzantine_validator = vote.signer;
             let double_proposal = vote.proposal;
 
-            return vec![ConsensusResponse::ViolationReport {
+            response.extend(vec![ConsensusResponse::ViolationReport {
                 violator: byzantine_validator,
                 misbehavior: Misbehavior::DoublePrecommit {
                     byzantine_node: byzantine_validator,
                     round: target_round,
                     proposals: (*origin_proposal, double_proposal),
                 },
-            }];
+            }]);
         }
     }
-
-    Vec::new()
+    response
 }