Revert "Event: remove guard for falsy handler argument of jQuery#on method"

This reverts commit fac67a984268ef8f7de952666fda6d8d32754f5f.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/event.js b/src/event.js
index ddd92c5fc..280581249 100644
--- a/src/event.js
+++ b/src/event.js
@@ -70,6 +70,8 @@ function on( elem, types, selector, data, fn, one ) {
 	}
 	if ( fn === false ) {
 		fn = returnFalse;
+	} else if ( !fn ) {
+		return this;
 	}
 
 	if ( one === 1 ) {
@@ -654,7 +656,6 @@ jQuery.each( {
 } );
 
 jQuery.fn.extend( {
-
 	on: function( types, selector, data, fn ) {
 		return on( this, types, selector, data, fn );
 	},
diff --git a/test/unit/event.js b/test/unit/event.js
index cdebbb4e7..b207441c9 100644
--- a/test/unit/event.js
+++ b/test/unit/event.js
@@ -6,7 +6,6 @@ QUnit.module( "event", {
 } );
 
 QUnit.test( "on() with non-null,defined data", function( assert ) {
-
 	assert.expect( 2 );
 
 	var handler = function( event, data ) {