Autocomplete: Search if the user retypes the same value

Fixes #7434
Closes jquerygh-1238

Author: tjvantoll

tests/unit/autocomplete/autocomplete_core.js

@@ -338,4 +338,25 @@ test( ".replaceWith() (#9172)", function() {
 	equal( parent.html().toLowerCase(), replacement );
 });
 
+asyncTest( "Search if the user retypes the same value (#7434)", function() {
+	expect( 3 );
+	var element = $( "#autocomplete" ).autocomplete({
+			source: [ "java", "javascript" ],
+			delay: 0
+		}),
+		menu = element.autocomplete( "instance" ).menu.element;
+
+	element.val( "j" ).simulate( "keydown" );
+	setTimeout(function() {
+		ok( menu.is( ":visible" ), "menu displays initially" );
+		element.trigger( "blur" );
+		ok( !menu.is( ":visible" ), "menu hidden after blur" );
+		element.val( "j" ).simulate( "keydown" );
+		setTimeout(function() {
+			ok( menu.is( ":visible" ), "menu displays after typing the same value" );
+			start();
+		});
+	});
+});
+
 }( jQuery ) );

ui/autocomplete.js

@@ -394,8 +394,13 @@ $.widget( "ui.autocomplete", {
 	_searchTimeout: function( event ) {
 		clearTimeout( this.searching );
 		this.searching = this._delay(function() {
-			// only search if the value has changed
-			if ( this.term !== this._value() ) {
+
+			// Search if the value has changed, or if the user retypes the same value (see #7434)
+			var equalValues = this.term === this._value(),
+				menuVisible = this.menu.element.is( ":visible" ),
+				modifierKey = event.altKey || event.ctrlKey || event.metaKey || event.shiftKey;
+
+			if ( !equalValues || ( equalValues && !menuVisible && !modifierKey ) ) {
 				this.selectedItem = null;
 				this.search( null, event );
 			}