Autocomplete: Re-enable native autocomplete whent he page is unloaded…

…. Fixes #7790 - Autocomplete-enabled text input does not keep value when using back button in browser.

ui/jquery.ui.autocomplete.js

@@ -215,6 +215,13 @@ $.widget( "ui.autocomplete", {
 		if ( $.fn.bgiframe ) {
 			 this.menu.element.bgiframe();
 		}
+		// turning off autocomplete prevents the browser from remembering the
+		// value when navigating through history, so we re-enable autocomplete
+		// if the page is unloaded before the widget is destroyed. #7790
+		self.beforeunloadHandler = function() {
+			self.element.removeAttr( "autocomplete" );
+		};
+		$( window ).bind( "beforeunload", self.beforeunloadHandler );
 	},
 
 	destroy: function() {
@@ -225,6 +232,7 @@ $.widget( "ui.autocomplete", {
 			.removeAttr( "aria-autocomplete" )
 			.removeAttr( "aria-haspopup" );
 		this.menu.element.remove();
+		$( window ).unbind( "beforeunload", this.beforeunloadHandler );
 		$.Widget.prototype.destroy.call( this );
 	},