Event: Avoid collisions between jQuery.event.special & Object.prototype

This is a follow-up to similar changes to data & event storages from
gh-4603.

Closes gh-5235
Ref gh-4603

src/event.js

@@ -429,7 +429,7 @@ jQuery.event = {
 			new jQuery.Event( originalEvent );
 	},
 
-	special: {
+	special: jQuery.extend( Object.create( null ), {
 		load: {
 
 			// Prevent triggered image.load events from bubbling to window.load
@@ -494,7 +494,7 @@ jQuery.event = {
 				}
 			}
 		}
-	}
+	} )
 };
 
 // Ensure the presence of an event listener that handles manually-triggered

test/unit/event.js

@@ -2428,6 +2428,26 @@ QUnit.test( ".on and .off, selective mixed removal (trac-10705)", function( asse
 		.trigger( "click" );	// 0
 } );
 
+QUnit.test( "special interference with Object.prototype", function( assert ) {
+	assert.expect( 1 );
+
+	var triggered = false;
+
+	Object.prototype.jqfake = {
+		trigger: function() {
+			triggered = true;
+		}
+	};
+
+	jQuery( "<div></div>" )
+		.appendTo( "#qunit-fixture" )
+		.trigger( "jqfake" );
+
+	delete Object.prototype.jqfake;
+
+	assert.ok( !triggered, "Object.prototype.jqfake.trigger not called" );
+} );
+
 QUnit.test( ".on( event-map, null-selector, data ) trac-11130", function( assert ) {
 
 	assert.expect( 1 );