Event: Evaluate delegate selectors at add time

This ensures that invalid selectors throw right away.

Fixes gh-3071
Closes gh-3097

Author: fsateler

src/event.js

@@ -120,6 +120,11 @@ jQuery.event = {
 			selector = handleObjIn.selector;
 		}
 
+		// If the selector is invalid, throw any exceptions at attach time
+		if ( selector ) {
+			jQuery.find( selector, elem );
+		}
+
 		// Make sure that the handler has a unique ID, used to find/remove it later
 		if ( !handler.guid ) {
 			handler.guid = jQuery.guid++;

test/unit/event.js

@@ -1289,6 +1289,19 @@ QUnit.test( "Delegated events in SVG (#10791; #13180)", function( assert ) {
 	jQuery( "#qunit-fixture" ).off( "click" );
 } );
 
+QUnit.test( "Delegated events with malformed selectors (#3071)", function( assert ) {
+	assert.expect( 2 );
+
+	assert.throws( function () {
+		jQuery( "#qunit-fixture" ).on( "click", "div:not", function () { } );
+	}, null, "malformed selector throws on attach" );
+
+	jQuery( "#qunit-fixture" ).click();
+	assert.ok( true, "malformed selector does not throw on event" );
+
+	jQuery( "#qunit-fixture" ).off( "click" );
+} );
+
 QUnit.test( "Delegated events in forms (#10844; #11145; #8165; #11382, #11764)", function( assert ) {
 	assert.expect( 5 );