René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"isXMLDoc() - Uncaught TypeError: Cannot read property 'namespaceURI' of undefined","articleBody":"\u003c!--\r\nFeature Requests:\r\n  Please read https://github.com/jquery/jquery/wiki/Adding-new-features\r\n  Most features should start as plugins outside of jQuery.\r\n\r\nBug Reports:\r\n  Note that we only can fix bugs in the latest version of jQuery.\r\n  Briefly describe the issue you've encountered\r\n  *  What do you expect to happen?\r\n  *  What actually happens?\r\n  *  Which browsers are affected?\r\n  Provide a *minimal* test case, see https://webkit.org/test-case-reduction/\r\n  Use the latest shipping version of jQuery in your test case!\r\n  We prefer test cases on JS Bin (https://jsbin.com/qawicop/edit?html,css,js,output) or CodePen (https://codepen.io/mgol/pen/wNWJbZ)\r\n\r\nFrequently Reported Issues:\r\n  * Self-closing tags broken in jQuery 3.5.0 or newer: please read the [jQuery 3.5.0 blog post](https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/) \u0026 the [upgrade guide](https://jquery.com/upgrade-guide/3.5/); see also issue #4681.\r\n--\u003e\r\n\r\n### Description ###\r\n\r\n`isXMLDoc()` throws an error if `undefined` given, starting from version 3.4.0\r\n\r\n#### Test script:\r\n`jQuery.isXMLDoc(undefined)`\r\n\r\n#### jQuery 3.3.1 result:\r\n`false`\r\n\r\n#### jQuery 3.5.1 (currently the latest, but starting from 3.4.0) result:\r\n`Uncaught TypeError: Cannot read property 'namespaceURI' of undefined`\r\n\r\n#### Techinfo\r\n\r\nBefore the **Sizzle** update from 2.3.3 to 2.3.4 (see related commit below), `isXML()` function looked liked this:\r\n```\r\nisXML = Sizzle.isXML = function( elem ) {\r\n\t// documentElement is verified for cases where it doesn't yet exist\r\n\t// (such as loading iframes in IE - #4833)\r\n\tvar documentElement = elem \u0026\u0026 (elem.ownerDocument || elem).documentElement;\r\n\treturn documentElement ? documentElement.nodeName !== \"HTML\" : false;\r\n};\r\n```\r\n\r\nThis **doesn't throw an error**, when the `elem` is `undefined`, because it checks it.\r\n\r\nIn the update from 3.4.0, it looks like this:\r\n```\r\nisXML = Sizzle.isXML = function( elem ) {\r\n\tvar namespace = elem.namespaceURI,\r\n\t\tdocElem = ( elem.ownerDocument || elem ).documentElement;\r\n\r\n\t// Support: IE \u003c=8\r\n\t// Assume HTML when documentElement doesn't yet exist, such as inside loading iframes\r\n\t// https://bugs.jquery.com/ticket/4833\r\n\treturn !rhtml.test( namespace || docElem \u0026\u0026 docElem.nodeName || \"HTML\" );\r\n};\r\n```\r\n\r\nThis **throws an error** when the `elem` is `undefined`:\r\n`Uncaught TypeError: Cannot read property 'namespaceURI' of undefined`\r\n\r\n**Please, if you can, bring back the previous functionality: `undefined` is not an XML node, so it should return a false boolean instead of a TypeError.**\r\n\r\nThanks in advance!\r\n\r\n### Additional info ###\r\n\r\nRelated commit: https://github.com/jquery/jquery/commit/d940bc063cd5ae09bf52067bbe046fda88f1f687 (from line 562)\r\nRelated blog-post: https://blog.jquery.com/2019/04/10/jquery-3-4-0-released/","author":{"url":"https://github.com/borzaka","@type":"Person","name":"borzaka"},"datePublished":"2020-08-29T12:20:37.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/4782/jquery/issues/4782"}