Additional fixes to perl API.

Bug 1770
Prevent segfaults and return reservation with NULL partition.

contribs/perlapi/libslurm/perl/reservation.c

@@ -86,7 +86,7 @@ hv_to_reserve_info(HV *hv, reserve_info_t *resv_info)
 		/* nothing to do */
 	}
 	FETCH_FIELD(hv, resv_info, node_list, charp, FALSE);
-	FETCH_FIELD(hv, resv_info, partition, charp, TRUE);
+	FETCH_FIELD(hv, resv_info, partition, charp, FALSE);
 	FETCH_FIELD(hv, resv_info, start_time, time_t, TRUE);
 	FETCH_FIELD(hv, resv_info, users, charp, FALSE);
 	return 0;

contribs/perlapi/libslurm/perl/step.c

@@ -68,6 +68,8 @@ hv_to_job_step_info(HV *hv, job_step_info_t *step_info)
 	AV *av;
 	int i, n;
 
+	memset(step_info, 0, sizeof(job_step_info_t));
+
 	FETCH_FIELD(hv, step_info, array_job_id, uint32_t, TRUE);
 	FETCH_FIELD(hv, step_info, array_task_id, uint32_t, TRUE);
 	FETCH_FIELD(hv, step_info, ckpt_dir, charp, FALSE);

src/api/job_step_info.c

@@ -200,7 +200,7 @@ slurm_sprint_job_step_info ( job_step_info_t * job_step_ptr,
 		 job_state_string(job_step_ptr->state));
 	xstrcat(out, tmp_line);
 	if (cluster_flags & CLUSTER_FLAG_BG) {
-		char *io_nodes;
+		char *io_nodes = NULL;
 		select_g_select_jobinfo_get(job_step_ptr->select_jobinfo,
 					    SELECT_JOBDATA_IONODES,
 					    &io_nodes);