Ticket #39341: 39341.diff

src/wp-includes/js/wp-api.js

@@ -185 +185 @@
                                         } else {
 
                                                 // We already have args, merge these new args in.
-                                                modelInstance.prototype.args = _.union( routeEndpoint.args, modelInstance.prototype.defaults );
+                                                modelInstance.prototype.args = _.extend( modelInstance.prototype.args, routeEndpoint.args );
                                         }
                                 }
                         } else {
@@ -202 +202 @@
                                                 } else {
 
                                                         // We already have options, merge these new args in.
-                                                        modelInstance.prototype.options = _.union( routeEndpoint.args, modelInstance.prototype.options );
+                                                        modelInstance.prototype.options = _.extend( modelInstance.prototype.options, routeEndpoint.args );
                                                 }
                                         }