Fix #8545. Plug event handling memory leak in oldIE.

src/data.js

@@ -6,6 +6,8 @@ var rbrace = /^(?:\{.*\}|\[.*\])$/,
 jQuery.extend({
 	cache: {},
 
+	deletedIds: [],
+
 	// Please use with caution
 	uuid: 0,
 
@@ -59,7 +61,7 @@ jQuery.extend({
 			// Only DOM nodes need a new unique ID for each element since their data
 			// ends up in the global cache
 			if ( isNode ) {
-				elem[ internalKey ] = id = ++jQuery.uuid;
+				elem[ internalKey ] = id = jQuery.deletedIds.pop() || ++jQuery.uuid;
 			} else {
 				id = internalKey;
 			}
@@ -212,6 +214,8 @@ jQuery.extend({
 		// We destroyed the cache and need to eliminate the expando on the node to avoid
 		// false lookups in the cache for entries that no longer exist
 		if ( isNode ) {
+			jQuery.deletedIds.push( id );
+
 			// IE does not allow us to delete expando properties from nodes,
 			// nor does it have a removeAttribute function on Document nodes;
 			// we must handle all of these cases

src/event.js

@@ -154,7 +154,7 @@ jQuery.event = {
 
 		var elemData = jQuery.hasData( elem ) && jQuery._data( elem ),
 			t, tns, type, origType, namespaces, origCount,
-			j, events, special, handle, eventType, handleObj;
+			j, events, special, eventType, handleObj;
 
 		if ( !elemData || !(events = elemData.events) ) {
 			return;
@@ -213,14 +213,11 @@ jQuery.event = {
 
 		// Remove the expando if it's no longer used
 		if ( jQuery.isEmptyObject( events ) ) {
-			handle = elemData.handle;
-			if ( handle ) {
-				handle.elem = null;
-			}
+			delete elemData.handle;
 
 			// removeData also checks for emptiness and clears the expando if empty
 			// so use it instead of delete
-			jQuery.removeData( elem, [ "events", "handle" ], true );
+			jQuery.removeData( elem, "events", true );
 		}
 	},
 
@@ -636,8 +633,17 @@ jQuery.removeEvent = document.removeEventListener ?
 		}
 	} :
 	function( elem, type, handle ) {
+		var name = "on" + type;
+
 		if ( elem.detachEvent ) {
-			elem.detachEvent( "on" + type, handle );
+
+			// #8545, #7054, preventing memory leaks for custom events in IE6-8 –
+			// detachEvent needed property on element, by name of that event, to properly expose it to GC
+			if ( typeof elem[ name ] === "undefined" ) {
+				elem[ name ] = null;
+			}
+
+			elem.detachEvent( name, handle );
 		}
 	};
 

src/manipulation.js

@@ -811,21 +811,20 @@ jQuery.extend({
 							jQuery.removeEvent( elem, type, data.handle );
 						}
 					}
-
-					// Null the DOM reference to avoid IE6/7/8 leak (#7054)
-					if ( data.handle ) {
-						data.handle.elem = null;
-					}
 				}
 
-				if ( deleteExpando ) {
-					delete elem[ jQuery.expando ];
+				// Remove cache only if jQuery.event.remove was not removed it before
+				if ( cache[ id ] ) {
+					if ( deleteExpando ) {
+						delete elem[ jQuery.expando ];
 
-				} else if ( elem.removeAttribute ) {
-					elem.removeAttribute( jQuery.expando );
-				}
+					} else if ( elem.removeAttribute ) {
+						elem.removeAttribute( jQuery.expando );
+					}
 
-				delete cache[ id ];
+					jQuery.deletedIds.push( id );
+					delete cache[ id ];
+				}
 			}
 		}
 	}