Fix n_nibbles_in_key computation.

HerodotusDev · Apr 22, 2024 · 36e907e · 36e907e
1 parent 0d12d0c
commit 36e907e
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/lib/mpt.cairo b/lib/mpt.cairo
@@ -354,8 +354,13 @@ func decode_node_list_lazy{range_check_ptr, bitwise_ptr: BitwiseBuiltin*}(
                     assert key_bits = key_bit_low;
                 }
             }
-            let (n_nibbles_in_key, remainder) = felt_divmod(key_bits, 4);
-            assert remainder = 0;
+            local n_nibbles_in_key: felt;  // <=> ceil(key_bits/4)
+            let (n_nibbles_in_key_tmp, remainder) = felt_divmod(key_bits, 4);
+            if (remainder != 0) {
+                assert n_nibbles_in_key = n_nibbles_in_key_tmp + 1;
+            } else {
+                assert n_nibbles_in_key = n_nibbles_in_key_tmp;
+            }
             assert n_nibbles_in_key = n_nibbles_already_checked;
             tempvar range_check_ptr = range_check_ptr;
             tempvar bitwise_ptr = bitwise_ptr;