Cherry pick fix for freeze (#4459)

* check freeze before updating slot_hashes (#4448)

* check freeze before updating slot_hashes

* fixup

* add more information to dropped vote warning (#4449)

* add more information to dropped vote warning

* fixup

programs/vote_api/src/vote_state.rs

@@ -145,10 +145,22 @@ impl VoteState {
             .iter()
             .any(|(slot, hash)| vote.slot == *slot && vote.hash == *hash)
         {
+            if log_enabled!(log::Level::Warn) {
+                for (slot, hash) in slot_hashes {
+                    if vote.slot == *slot {
                         warn!(
-                "dropping vote {:?}, no matching slot/hash combination",
-                vote
+                            "dropped vote {:?} matched slot {}, but not hash {:?}",
+                            vote, *slot, *hash
                         );
+                    }
+                    if vote.hash == *hash {
+                        warn!(
+                            "dropped vote {:?} matched hash {:?}, but not slot {}",
+                            vote, *hash, *slot,
+                        );
+                    }
+                }
+            }
             return;
         }
 

runtime/src/bank.rs

@@ -215,19 +215,23 @@ impl Bank {
         self.store(&slot_hashes::id(), &account);
     }
 
-    fn set_hash(&self) {
+    fn set_hash(&self) -> bool {
         let mut hash = self.hash.write().unwrap();
 
         if *hash == Hash::default() {
             //  freeze is a one-way trip, idempotent
             *hash = self.hash_internal_state();
+            true
+        } else {
+            false
         }
     }
 
     pub fn freeze(&self) {
-        self.set_hash();
+        if self.set_hash() {
             self.update_slot_hashes();
         }
+    }
 
     pub fn epoch_schedule(&self) -> &EpochSchedule {
         &self.epoch_schedule