Issue #857: fix a few places where json_tokener should have been returning json_tokener_error_memory but wasn't.

json_tokener.c

@@ -344,6 +344,7 @@ struct json_object *json_tokener_parse_ex(struct json_tokener *tok, const char *
 		newloc = newlocale(LC_NUMERIC_MASK, "C", duploc);
 		if (newloc == NULL)
 		{
+			tok->err = json_tokener_error_memory;
 			freelocale(duploc);
 			return NULL;
 		}
@@ -362,7 +363,10 @@ struct json_object *json_tokener_parse_ex(struct json_tokener *tok, const char *
 		{
 			oldlocale = strdup(tmplocale);
 			if (oldlocale == NULL)
+			{
+				tok->err = json_tokener_error_memory;
 				return NULL;
+			}
 		}
 		setlocale(LC_NUMERIC, "C");
 	}
@@ -1257,7 +1261,11 @@ struct json_object *json_tokener_parse_ex(struct json_tokener *tok, const char *
 			goto redo_char;
 
 		case json_tokener_state_object_value_add:
-			json_object_object_add(current, obj_field_name, obj);
+			if (json_object_object_add(current, obj_field_name, obj) != 0)
+			{
+				tok->err = json_tokener_error_memory;
+				goto out;
+			}
 			free(obj_field_name);
 			obj_field_name = NULL;
 			saved_state = json_tokener_state_object_sep;