Fix #13514: Set selectedIndex to -1 when non-matching value is set on a select. Close gh-1191.

src/attributes.js

@@ -275,13 +275,20 @@ jQuery.extend({
 			},
 
 			set: function( elem, value ) {
-				var values = jQuery.makeArray( value );
+				var optionSet, option,
+					options = elem.options,
+					values = jQuery.makeArray( value ),
+					i = options.length;
 				
-				jQuery(elem).find("option").each(function() {
-					this.selected = jQuery.inArray( jQuery(this).val(), values ) >= 0;
-				});
+				while ( i-- ) {
+					option = options[ i ];
+					if ( (option.selected = jQuery.inArray( jQuery(option).val(), values ) >= 0) ) {
+						optionSet = true;
+					}
+				}
 				
-				if ( !values.length ) {
+				// force browsers to behave consistently when non-matching value is set
+				if ( !optionSet ) {
 					elem.selectedIndex = -1;
 				}
 				return values;

test/unit/attributes.js

@@ -850,6 +850,22 @@ test( "val()", function() {
 	equal( jQuery("<option/>").val("test").attr("value"), "test", "Setting value sets the value attribute" );
 });
 
+test("val() with non-matching values on dropdown list", function() {
+	expect( 3 );
+	
+	jQuery("#select5").val( "" );
+	equal( jQuery("#select5").val(), null, "Non-matching set on select-one" );
+	
+	var select6 = jQuery("<select multiple id=\"select6\"><option value=\"1\">A</option><option value=\"2\">B</option></select>").appendTo("#form");
+	jQuery(select6).val( "nothing" );
+	equal( jQuery(select6).val(), null, "Non-matching set (single value) on select-multiple" );
+	
+	jQuery(select6).val( ["nothing1", "nothing2"] );
+	equal( jQuery(select6).val(), null, "Non-matching set (array of values) on select-multiple" );
+	
+	select6.remove();
+});
+
 if ( "value" in document.createElement("meter") &&
 			"value" in document.createElement("progress") ) {