Adjust the return value of the tabIndex propHook to match the spec. Fixes #13752.

src/attributes.js

@@ -414,20 +414,14 @@ jQuery.extend({
 		}
 
 		if ( value !== undefined ) {
-			if ( hooks && "set" in hooks && (ret = hooks.set( elem, value, name )) !== undefined ) {
-				return ret;
+			return hooks && "set" in hooks && (ret = hooks.set( elem, value, name )) !== undefined ?
+				ret :
+				( elem[ name ] = value );
 
 		} else {
-				return ( elem[ name ] = value );
-			}
-
-		} else {
-			if ( hooks && "get" in hooks && (ret = hooks.get( elem, name )) !== null ) {
-				return ret;
-
-			} else {
-				return elem[ name ];
-			}
+			return hooks && "get" in hooks && (ret = hooks.get( elem, name )) !== null ?
+				ret :
+				elem[ name ];
 		}
 	},
 
@@ -442,7 +436,7 @@ jQuery.extend({
 					parseInt( attributeNode.value, 10 ) :
 					rfocusable.test( elem.nodeName ) || rclickable.test( elem.nodeName ) && elem.href ?
 						0 :
-						undefined;
+						-1;
 			}
 		}
 	}

test/index.html

@@ -272,6 +272,12 @@ Z</textarea>
 			<span>...</span><a id="linkWithNoHrefWithNoTabIndex">Eat a burger</a><span>...</span>
 			<span>...</span><a id="linkWithNoHrefWithTabIndex" tabindex="1">Eat some funyuns</a><span>...</span>
 			<span>...</span><a id="linkWithNoHrefWithNegativeTabIndex" tabindex="-1">Eat some funyuns</a><span>...</span>
+			<input id="inputWithoutTabIndex"/>
+			<button id="buttonWithoutTabIndex"></button>
+			<textarea id="textareaWithoutTabIndex"></textarea>
+			<menu type="popup">
+				<menuitem id="menuitemWithoutTabIndex" command="submitbutton" default/>
+			</menu>
 		</div>
 
 		<div id="liveHandlerOrder">

test/unit/attributes.js

@@ -687,11 +687,16 @@ test( "prop(String, Object)", function() {
 });
 
 test( "prop('tabindex')", function() {
-	expect( 8 );
+	expect( 11 );
+
+	// inputs without tabIndex attribute
+	equal( jQuery("#inputWithoutTabIndex").prop("tabindex"), 0, "input without tabindex" );
+	equal( jQuery("#buttonWithoutTabIndex").prop("tabindex"), 0, "button without tabindex" );
+	equal( jQuery("#textareaWithoutTabIndex").prop("tabindex"), 0, "textarea without tabindex" );
 
 	// elements not natively tabbable
 	equal( jQuery("#listWithTabIndex").prop("tabindex"), 5, "not natively tabbable, with tabindex set to 0" );
-	equal( jQuery("#divWithNoTabIndex").prop("tabindex"), undefined, "not natively tabbable, no tabindex set" );
+	equal( jQuery("#divWithNoTabIndex").prop("tabindex"), -1, "not natively tabbable, no tabindex set" );
 
 	// anchor with href
 	equal( jQuery("#linkWithNoTabIndex").prop("tabindex"), 0, "anchor with href, no tabindex set" );
@@ -699,7 +704,7 @@ test( "prop('tabindex')", function() {
 	equal( jQuery("#linkWithNegativeTabIndex").prop("tabindex"), -1, "anchor with href, tabindex set to -1" );
 
 	// anchor without href
-	equal( jQuery("#linkWithNoHrefWithNoTabIndex").prop("tabindex"), undefined, "anchor without href, no tabindex set" );
+	equal( jQuery("#linkWithNoHrefWithNoTabIndex").prop("tabindex"), -1, "anchor without href, no tabindex set" );
 	equal( jQuery("#linkWithNoHrefWithTabIndex").prop("tabindex"), 1, "anchor without href, tabindex set to 2" );
 	equal( jQuery("#linkWithNoHrefWithNegativeTabIndex").prop("tabindex"), -1, "anchor without href, no tabindex set" );
 });
@@ -709,7 +714,7 @@ test( "prop('tabindex', value)", 10, function() {
 	var clone,
 		element = jQuery("#divWithNoTabIndex");
 
-	equal( element.prop("tabindex"), undefined, "start with no tabindex" );
+	equal( element.prop("tabindex"), -1, "start with no tabindex" );
 
 	// set a positive string
 	element.prop( "tabindex", "1" );