1 files changed, 11 insertions, 2 deletions

diff --git a/src/alg.c b/src/alg.c
index 27af676..4f5079a 100644
--- a/src/alg.c
+++ b/src/alg.c
@@ -268,27 +268,31 @@ move_string(Move m)
 Alg *
 new_alg(char *str)
 {
-        Alg *alg = malloc(sizeof(Alg));
+        Alg *alg;
         int i;
-        bool niss = false, move_read;
+        bool niss, move_read;
         Move j, m;
 
+        alg = malloc(sizeof(Alg));
         alg->move      = malloc(30 * sizeof(Move));
         alg->inv       = malloc(30 * sizeof(bool));
         alg->allocated = 30;
         alg->len       = 0;
 
+        niss = false;
         for (i = 0; str[i]; i++) {
                 if (str[i] == ' ' || str[i] == '\t' || str[i] == '\n')
                         continue;
 
                 if (str[i] == '(' && niss) {
                         fprintf(stderr, "Error reading moves: nested ( )\n");
+                        alg->len = 0;
                         return alg;
                 }
 
                 if (str[i] == ')' && !niss) {
                         fprintf(stderr, "Error reading moves: unmatched )\n");
+                        alg->len = 0;
                         return alg;
                 }
 
@@ -353,6 +357,11 @@ new_alg(char *str)
                 }
         }
 
+        if (niss) {
+                fprintf(stderr, "Error reading moves: unmatched (\n");
+                alg->len = 0;
+        }
+
         return alg;
 }