Sortable: Fix a bug of removing an item while iterating an array. Fixes #8571 - Out of range problem in when dragging a nested sortable.

Author: zhizhangchen

ui/jquery.ui.sortable.js

@@ -562,14 +562,13 @@ $.widget("ui.sortable", $.ui.mouse, {
 
 		var list = this.currentItem.find(":data(" + this.widgetName + "-item)");
 
-		for (var i=0; i < this.items.length; i++) {
-
+		this.items = $.grep(this.items, function (item) {
 			for (var j=0; j < list.length; j++) {
-				if(list[j] == this.items[i].item[0])
-					this.items.splice(i,1);
+				if(list[j] == item.item[0])
+					return false;
 			};
-
-		};
+			return true;
+		});
 
 	},