Invert chain selection arguments order

To maintain consistency.

Author: gabrielbosio

operator/mina/lib/src/consensus_state.rs

@@ -9,23 +9,23 @@ pub enum LongerChainResult {
 }
 
 pub fn select_longer_chain(
-    tip: &MinaStateProtocolStateValueStableV2,
     candidate: &MinaStateProtocolStateValueStableV2,
+    tip: &MinaStateProtocolStateValueStableV2,
 ) -> LongerChainResult {
-    let tip_block_height = &tip.body.consensus_state.blockchain_length.as_u32();
     let candidate_block_height = &candidate.body.consensus_state.blockchain_length.as_u32();
+    let tip_block_height = &tip.body.consensus_state.blockchain_length.as_u32();
 
-    if tip_block_height < candidate_block_height {
+    if candidate_block_height > tip_block_height {
         return LongerChainResult::Candidate;
     }
     // tiebreak logic
-    else if tip_block_height == candidate_block_height {
+    else if candidate_block_height == tip_block_height {
         // compare last VRF digests lexicographically
-        if hash_last_vrf(tip) < hash_last_vrf(candidate) {
+        if hash_last_vrf(candidate) > hash_last_vrf(tip) {
             return LongerChainResult::Candidate;
-        } else if hash_last_vrf(tip) == hash_last_vrf(candidate) {
+        } else if hash_last_vrf(candidate) == hash_last_vrf(tip) {
             // compare consensus state hashes lexicographically
-            if hash_state(tip) < hash_state(candidate) {
+            if hash_state(candidate) > hash_state(tip) {
                 return LongerChainResult::Candidate;
             }
         }

operator/mina/lib/src/lib.rs

@@ -81,7 +81,7 @@ pub extern "C" fn verify_protocol_state_proof_ffi(
     }
 
     // Consensus check: Short fork rule
-    let longer_chain = select_longer_chain(&tip_protocol_state, &candidate_protocol_state);
+    let longer_chain = select_longer_chain(&candidate_protocol_state, &tip_protocol_state);
 
     longer_chain == LongerChainResult::Candidate
 }