fix plutus map serialization for multiple keys

Author: lisicky

rust/src/protocol_types/plutus/plutus_data.rs

@@ -150,6 +150,10 @@ impl PlutusMap {
             .or_insert_with(PlutusMapValues::new);
         values.add_move(value);
     }
+
+    pub(crate) fn total_len(&self) -> usize {
+        self.0.iter().map(|(_k, v)| v.len()).sum()
+    }
 }
 
 #[wasm_bindgen]

rust/src/serialization/plutus/plutus_data.rs

@@ -69,7 +69,7 @@ impl cbor_event::se::Serialize for PlutusMap {
         &self,
         serializer: &'se mut Serializer<W>,
     ) -> cbor_event::Result<&'se mut Serializer<W>> {
-        serializer.write_map(cbor_event::Len::Len(self.0.len() as u64))?;
+        serializer.write_map(cbor_event::Len::Len(self.total_len() as u64))?;
         for (key, values) in &self.0 {
             for value in &values.elems {
                 key.serialize(serializer)?;

rust/src/tests/general.rs

@@ -818,4 +818,37 @@ fn test_multiple_tiers() {
         let result = min_ref_script_fee(*size, &new_uinternal(1, 1000)).unwrap();
         assert_eq!(result.to_str(), *expected, "Failed for size {}", size);
     }
+}
+
+#[test]
+fn plutus_map_keys_duplication_test() {
+    let mut map = PlutusMap::new();
+    let key1 = PlutusData::new_integer(&BigInt::from(1));
+    let key2 = PlutusData::new_integer(&BigInt::from(2));
+    let value1 = PlutusData::new_integer(&BigInt::from(3));
+    let value2 = PlutusData::new_integer(&BigInt::from(4));
+    let value3 = PlutusData::new_integer(&BigInt::from(5));
+
+    assert_eq!(map.len(), 0);
+    assert_eq!(map.total_len(), 0);
+
+    let mut plutus_map_value1 = PlutusMapValues::new();
+    plutus_map_value1.add(&value1);
+    plutus_map_value1.add(&value2);
+
+    let mut plutus_map_value2 = PlutusMapValues::new();
+    plutus_map_value2.add(&value3);
+
+    map.insert(&key1, &plutus_map_value1);
+    map.insert(&key2, &plutus_map_value2);
+
+    assert_eq!(map.len(), 2);
+    assert_eq!(map.total_len(), 3);
+
+    let map_bytes = map.to_bytes();
+    let map_from_bytes = PlutusMap::from_bytes(map_bytes).unwrap();
+    assert_eq!(map_from_bytes.len(), 2);
+    assert_eq!(map_from_bytes.total_len(), 3);
+
+    assert_eq!(map, map_from_bytes)
 }