Callbacks: Disabling a callback should prevent firing

dmethvin · dmethvin · commit bc1cb122db30 · 2014-12-07T20:51:04.000-05:00
Thanks to @TheDistantSea for the report! Fixes gh-1790 Closes gh-1643
diff --git a/src/callbacks.js b/src/callbacks.js
@@ -151,8 +151,10 @@ jQuery.Callbacks = function( options ) {
 			},
 			// Remove all callbacks from the list
 			empty: function() {
-				list = [];
-				firingLength = 0;
+				if ( list ) {
+					list = [];
+					firingLength = 0;
+				}
 				return this;
 			},
 			// Have the list do nothing anymore
diff --git a/test/unit/callbacks.js b/test/unit/callbacks.js
@@ -340,3 +340,18 @@ test( "jQuery.Callbacks() - adding a string doesn't cause a stack overflow", fun
 
 	ok( true, "no stack overflow" );
 });
+
+test( "jQuery.Callbacks() - disabled callback doesn't fire (gh-1790)", function() {
+
+	expect( 1 );
+
+	var cb = jQuery.Callbacks(),
+		fired = false,
+		shot = function() { fired = true; };
+
+	cb.disable();
+	cb.empty();
+	cb.add( shot );
+	cb.fire();
+	ok( !fired, "Disabled callback function didn't fire" );
+});
