Do not reserialize XHR content-types unnecessarily

See whatwg/xhr#224.
jsdom · May 28, 2019 · dd6c5a0 · dd6c5a0
1 parent 7cd5329
commit dd6c5a0
Show file tree

Hide file tree

Showing 3 changed files with 29 additions and 1 deletion.
diff --git a/lib/jsdom/living/xmlhttprequest.js b/lib/jsdom/living/xmlhttprequest.js
@@ -576,8 +576,8 @@ module.exports = function createXMLHttpRequest(window) {
               const charset = parsed.parameters.get("charset");
               if (charset && !asciiCaseInsensitiveMatch(charset, encoding) && encoding !== null) {
                 parsed.parameters.set("charset", encoding);
+                xhrUtils.updateRequestHeader(flag.requestHeaders, "content-type", parsed.toString());
               }
-              xhrUtils.updateRequestHeader(flag.requestHeaders, "content-type", parsed.toString());
             }
           }
         }

diff --git a/test/web-platform-tests/to-upstream/xhr/content-type-unmodified.html b/test/web-platform-tests/to-upstream/xhr/content-type-unmodified.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<title>A charset-including content-type header must not be modified (e.g. via reserialization)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+async_test(t => {
+  const xhr = new XMLHttpRequest();
+
+  xhr.open("POST", "resources/echo-content-type.py");
+  xhr.setRequestHeader("content-type", "application/json; charset=UTF-8");
+
+  xhr.onerror = t.unreached_func("Error occurred.");
+
+  xhr.onload = t.step_func_done(() => {
+    assert_equals(xhr.status, 200);
+    assert_equals(xhr.responseText, "application/json; charset=UTF-8");
+  });
+  xhr.send("{ \"x\":\"a\"}");
+});
+</script>
diff --git a/test/web-platform-tests/to-upstream/xhr/resources/echo-content-type.py b/test/web-platform-tests/to-upstream/xhr/resources/echo-content-type.py
@@ -0,0 +1,5 @@
+def main(request, response):
+    response.headers.set("Content-Type", "text/plain")
+    response.status = 200
+    response.content = request.headers["Content-Type"]
+    response.close_connection = True