check return value when output arg is NULL

src/tleaf.c

@@ -183,6 +183,7 @@ int tleaf_it_rank(const excit_t it, const ssize_t *indexes, ssize_t *n)
 		acc *= data_it->arities[i];
 	}
 
+	if (n != NULL)
 		*n = val;
 	return EXCIT_SUCCESS;
 }
@@ -377,6 +378,8 @@ int tleaf_it_split(const excit_t it, const ssize_t depth,
 
 	if (data_it->arities[depth] % n != 0)
 		return -EXCIT_EINVAL;
+	if (out == NULL)
+		return EXCIT_SUCCESS;
 
 	int err;
 	excit_t *levels, *levels_inverse;