Bug 1846780: responseXML is populated for a blob with an empty type. …

…r=twisniewski A blob with an empty content type or any other invalid content type should return a value for responseXML. Differential Revision: https://phabricator.services.mozilla.com/D185185
dothq · Aug 8, 2023 · 2e71051 · 2e71051
1 parent a117230
commit 2e71051
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Showing 2 changed files with 52 additions and 3 deletions.
diff --git a/dom/xhr/XMLHttpRequestMainThread.cpp b/dom/xhr/XMLHttpRequestMainThread.cpp
@@ -2061,9 +2061,9 @@ XMLHttpRequestMainThread::OnStartRequest(nsIRequest* request) {
       } else {
         mIsHtml = true;
       }
-    } else if (!(type.EqualsLiteral("text/xml") ||
-                 type.EqualsLiteral("application/xml") ||
-                 StringEndsWith(type, "+xml"_ns))) {
+    } else if (!type.IsEmpty() && (!(type.EqualsLiteral("text/xml") ||
+                                     type.EqualsLiteral("application/xml") ||
+                                     StringEndsWith(type, "+xml"_ns)))) {
       // Follow https://xhr.spec.whatwg.org/
       // If final MIME type is not null, text/html, text/xml, application/xml,
       // or does not end in +xml, return null.

diff --git a/testing/web-platform/mozilla/tests/xml/responsexml-content-type.html b/testing/web-platform/mozilla/tests/xml/responsexml-content-type.html
@@ -0,0 +1,49 @@
+<!doctype html>
+<html>
+  <head>
+    <title>XMLHttpRequest: responseXML content-type test</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <link rel="help" href="https://xhr.spec.whatwg.org/#dom-xmlhttprequest-responsexml"/>
+  </head>
+  <body>
+  </body>
+  <script>
+
+function parseBlob(blob) {
+  return new Promise(resolve => {
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", URL.createObjectURL(blob));
+    xhr.onload = () => {
+      resolve(xhr.responseXML);
+    }
+    xhr.send();
+  });
+}
+
+promise_test(async function() {
+  let blob = new Blob(["<x></x>"]);
+  let responseXML = await parseBlob(blob);
+  assert_not_equals(responseXML, null);
+}, "Empty MIME type should be equivalent to text/xml")
+
+promise_test(async function() {
+  let blob = new Blob(["<x></x>"], {type: "text/html"});
+  let responseXML = await parseBlob(blob);
+  assert_equals(responseXML, null);
+}, "HTML content type should return null")
+
+promise_test(async function() {
+  let blob = new Blob(["<x></x>"], {type: "text/plain"});
+  let responseXML = await parseBlob(blob);
+  assert_equals(responseXML, null);
+}, "Non XML or HTML content type should return null")
+
+promise_test(async function() {
+  let blob = new Blob(["<x></x>"], {type: "text/xml"});
+  let responseXML = await parseBlob(blob);
+  assert_not_equals(responseXML, null);
+}, "XML content type should parse")
+
+  </script>
+</html>