fix(driver): decide in a future round upon PrecommitValue(v) vote keeper output

code/crates/core-driver/src/driver.rs

@@ -315,6 +315,22 @@ where
             .get_proposal_and_validity_for_round_and_value(round, value_id)
     }
 
+    /// Returns a valid proposal for the given round and value_id, if any.
+    pub fn valid_proposal_for_round_and_value(
+        &self,
+        round: Round,
+        value_id: ValueId<Ctx>,
+    ) -> Option<&SignedProposal<Ctx>> {
+        if let Some((proposal, validity)) =
+            self.proposal_and_validity_for_round_and_value(round, value_id)
+        {
+            if validity.is_valid() {
+                return Some(proposal);
+            }
+        }
+        None
+    }
+
     /// Returns the proposals and their validities for the given round, if any.
     pub fn proposals_and_validities_for_round(
         &self,

code/crates/core-driver/src/mux.rs

@@ -298,17 +298,14 @@ where
             VKOutput::PrecommitAny => (threshold_round, RoundInput::PrecommitAny),
             VKOutput::SkipRound(r) => (threshold_round, RoundInput::SkipRound(r)),
             VKOutput::PrecommitValue(v) => {
-                if let Some((proposal, validity)) =
-                    self.proposal_and_validity_for_round_and_value(threshold_round, v)
+                if let Some(proposal) = self.valid_proposal_for_round_and_value(threshold_round, v)
                 {
-                    if validity.is_valid() {
-                        (
-                            threshold_round,
-                            RoundInput::ProposalAndPrecommitValue(proposal.message.clone()),
-                        )
-                    } else {
-                        (threshold_round, RoundInput::PrecommitAny)
-                    }
+                    (
+                        threshold_round,
+                        RoundInput::ProposalAndPrecommitValue(proposal.message.clone()),
+                    )
+                } else if threshold_round > self.round() {
+                    (threshold_round, RoundInput::SkipRound(threshold_round))
                 } else {
                     (threshold_round, RoundInput::PrecommitAny)
                 }