Event: add support comment

(cherry-picked from 9db9316609c2881dbb6abc49efc3aa91a57a02ad)

Ref gh-2047

diff --git a/src/event.js b/src/event.js
index 87ae3a65b17ee14cee072cd685cf284fef982863..a5b8d597d6f636918d0d955d0be586c2040725df 100644 (file)
--- a/src/event.js
+++ b/src/event.js
@@ -24,6 +24,8 @@ function returnFalse() {
        return false;
 }
 
+// Support: IE9
+// See #13393 for more info
 function safeActiveElement() {
        try {
                return document.activeElement;
@@ -439,7 +441,10 @@ jQuery.event = {
                        delegateCount = handlers.delegateCount,
                        cur = event.target;
 
+               // Support (at least): Chrome, IE9
                // Find delegate handlers
+               //
+               // Support: Firefox
                // Black-hole SVG <use> instance trees (#13180)
                // Avoid non-left-click bubbling in Firefox (#3861)
                if ( delegateCount && cur.nodeType && (!event.button || event.type !== "click") ) {
@@ -669,6 +674,8 @@ jQuery.event = {
 
 jQuery.removeEvent = document.removeEventListener ?
        function( elem, type, handle ) {
+
+               // This "if" is needed for plain objects
                if ( elem.removeEventListener ) {
                        elem.removeEventListener( type, handle, false );
                }