do not leak terrain.herbs

src/kernel/jsonconf.c

@@ -270,6 +270,7 @@ static void json_terrain(cJSON *json, terrain_type *ter) {
                 int size = cJSON_GetArraySize(child);
                 if (size > 0) {
                     int n;
+                    free(ter->herbs);
                     ter->herbs = malloc(sizeof(const item_type *) * (size + 1));
                     ter->herbs[size] = 0;
                     for (n = 0, entry = child->child; entry; entry = entry->next) {

src/kernel/terrain.c

@@ -63,6 +63,7 @@ void free_terrains(void)
         terrain_type * t = registered_terrains;
         registered_terrains = t->next;
         free(t->_name);
+        free(t->herbs);
         if (t->production) {
             for (n = 0; t->production[n].type; ++n) {
                 free(t->production[n].base);