Zero the output list structures before filling them.

src/output_list.c

@@ -330,6 +330,7 @@ void output_list_init(struct output_list **list, const struct engine *e,
 
   /* Read output_list for snapshots */
   *list = (struct output_list *)malloc(sizeof(struct output_list));
+  bzero(*list, sizeof(struct output_list));
   (*list)->output_list_on = output_list_on;
 
   /* Read filename */

src/output_options.c

@@ -51,6 +51,8 @@ const char* compression_level_names[compression_level_count] = {
 void output_options_init(struct swift_params* parameter_file, int mpi_rank,
                          struct output_options* output_options) {
 
+  bzero(output_options, sizeof(struct output_options));
+
   /* Load select_output */
   struct swift_params* select_output =
       (struct swift_params*)malloc(sizeof(struct swift_params));