<!DOCTYPE html> <!-- Test from https://bugzilla.mozilla.org/show_bug.cgi?id=819051 --> <head> <title>XMLHttpRequest: setRequestHeader() and open()</title> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <link rel="help" href="https://xhr.spec.whatwg.org/#the-open()-method"> <link rel="help" href="https://xhr.spec.whatwg.org/#the-setrequestheader()-method"> </head> <body> <p id="log"></p> <script type="text/javascript"> async_test(test => { var url = "resources/inspect-headers.py"; var xhr = new XMLHttpRequest(); xhr.open("GET", url + "?filter_name=x-appended-to-this"); xhr.setRequestHeader("X-appended-to-this", "False"); xhr.open("GET", url + "?filter_name=x-appended-to-this"); xhr.setRequestHeader("X-appended-to-this", "True"); xhr.onreadystatechange = test.step_func(() => { if (xhr.readyState == 4) { assert_equals(xhr.responseText, "X-appended-to-this: True\n", "Set headers record should have been cleared by open."); test_standard_header(); } }) xhr.send(); function test_standard_header () { var header_tested = "Accept"; var xhr = new XMLHttpRequest(); xhr.open("GET", url + "?filter_name=accept"); xhr.setRequestHeader("Accept", "foo/bar"); xhr.open("GET", url + "?filter_name=accept"); xhr.setRequestHeader("Accept", "bar/foo"); xhr.onreadystatechange = test.step_func(() => { if (xhr.readyState == 4) { assert_equals(xhr.responseText, "Accept: bar/foo\n", "Set headers record should have been cleared by open."); test.done(); } }) xhr.send(); } }) </script>