r536: fixed a memory issue

when winding back to an internal node

kann.c

@@ -211,14 +211,19 @@ void kann_rnn_start(kann_t *a)
 			kad_node_t *q = p->pre;
 			if (q->x) memcpy(p->x, q->x, kad_len(p) * sizeof(float));
 			else memset(p->x, 0, kad_len(p) * sizeof(float));
+			if (q->n_child > 0) free(q->x);
 			q->x = p->x;
 		}
 	}
 }
 
 void kann_rnn_end(kann_t *a)
 {
+	int i;
 	kad_ext_sync(a->n, a->v, a->x, a->g, a->c);
+	for (i = 0; i < a->n; ++i)
+		if (a->v[i]->pre && a->v[i]->pre->n_child > 0)
+			a->v[i]->pre->x = (float*)calloc(kad_len(a->v[i]->pre), sizeof(float));
 }
 
 static int kann_class_error_core(const kann_t *ann, int *base)

kann.h

@@ -27,7 +27,7 @@
 #ifndef KANN_H
 #define KANN_H
 
-#define KANN_VERSION "r535"
+#define KANN_VERSION "r536"
 
 #define KANN_F_IN       0x1   /* input */
 #define KANN_F_OUT      0x2   /* output */