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)
         {
-            warn!(
-                "dropping vote {:?}, no matching slot/hash combination",
-                vote
-            );
+            if log_enabled!(log::Level::Warn) {
+                for (slot, hash) in slot_hashes {
+                    if vote.slot == *slot {
+                        warn!(
+                            "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;
         }