Fix a case where it's valid to get no responses back -- return early

before invoking malloc(0).

This commit was SVN r8577.

orte/mca/rmgr/base/rmgr_base_context.c

@@ -168,13 +168,18 @@ int orte_rmgr_base_get_app_context(
         &num_values,
         &values
         );
-    if(rc != ORTE_SUCCESS)
+    if (rc != ORTE_SUCCESS) {
         goto cleanup;
+    }
 
     *num_context = 0;
     for(i=0; i<num_values; i++) {
         *num_context += values[i]->cnt;
     }
+    if (0 == *num_context) {
+        *app_context = NULL;
+        return ORTE_SUCCESS;
+    }
 
     *app_context = (orte_app_context_t**)malloc(*num_context * sizeof(orte_app_context_t*));
     for(i=0; i<num_values; i++) {