Bug 1276918 - restrict multipart/x-mixed-replace to non-document loads r=necko-reviewers,valentin,kershaw

freddyb · freddyb · commit 911a5882509d · 2023-12-06T14:07:34.000Z
Ideally, I would like to remove this for all types except images, but there is some uncertainty wrt to other media load types and making small steps is easier than huge strides. Especially when it's risking compatibility. Differential Revision: https://phabricator.services.mozilla.com/D194917
diff --git a/docshell/test/browser/browser_viewsource_multipart.js b/docshell/test/browser/browser_viewsource_multipart.js
@@ -8,6 +8,11 @@ const TEST_PATH = getRootDirectory(gTestPath).replace(
 );
 const MULTIPART_URI = `${TEST_PATH}file_basic_multipart.sjs`;
 
+add_setup(async () => {
+  await SpecialPowers.pushPrefEnv({
+    set: [["network.multipart-mixed-replace.enabled_for_document", true]],
+  });
+});
 add_task(async function viewsource_multipart_uri() {
   await BrowserTestUtils.withNewTab("about:blank", async browser => {
     BrowserTestUtils.startLoadingURIString(browser, MULTIPART_URI);
diff --git a/docshell/test/mochitest/test_bug1747033.html b/docshell/test/mochitest/test_bug1747033.html
@@ -87,9 +87,15 @@
         SimpleTest.finish();
       });
     }
+    SpecialPowers.pushPrefEnv({set:
+      [["network.multipart-mixed-replace.enabled_for_document", true]]},
+      () => {
+        runTest();
+      }
+    );
   </script>
 </head>
-<body onload="runTest();">
+<body>
 <p id="display"></p>
 <div id="content" style="display: none"></div>
 <pre id="test"></pre>
diff --git a/docshell/test/mochitest/test_bug660404.html b/docshell/test/mochitest/test_bug660404.html
@@ -65,7 +65,8 @@
 }
 
 // If Fission is disabled, the pref is no-op.
-SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true]]}, () => {
+SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true],
+  ["network.multipart-mixed-replace.enabled_for_document", true]]}, () => {
   // Have to open a new window, since there's no bfcache in subframes
   window.open("file_bug660404-1.html", "", "noopener");
 });
diff --git a/docshell/test/mochitest/test_compressed_multipart.html b/docshell/test/mochitest/test_compressed_multipart.html
@@ -33,8 +33,10 @@
   SimpleTest.finish();
 }
 
-w = window.open("file_compressed_multipart");
-
+SpecialPowers.pushPrefEnv({set:
+  [["network.multipart-mixed-replace.enabled_for_document", true]]}, () => {
+  w = window.open("file_compressed_multipart");
+});
 </script>
 </pre>
 </body>
diff --git a/dom/base/test/test_x-frame-options.html b/dom/base/test/test_x-frame-options.html
@@ -183,7 +183,9 @@
 
 // load the test harness
 SpecialPowers.pushPrefEnv({
-  "set": [["security.data_uri.block_toplevel_data_uri_navigations", false],]
+  "set": [["security.data_uri.block_toplevel_data_uri_navigations", false],
+  ["network.multipart-mixed-replace.enabled_for_document", true],
+]
 }, function() {
   document.getElementById("harness").src = "file_x-frame-options_main.html";
 });
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
@@ -11711,6 +11711,12 @@
   value: true
   mirror: always
 
+# Re-enables multipart/x-mixed-replace for DOCUMENT types
+- name: network.multipart-mixed-replace.enabled_for_document
+  type: RelaxedAtomicBool
+  value: false
+  mirror: always
+
 # Enables `<link rel="modulepreload">` tag and `Link: rel=modulepreload`
 # response header handling.
 - name: network.modulepreload
diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -1703,7 +1703,10 @@ nsresult nsHttpChannel::CallOnStartRequest() {
     nsAutoCString contentType;
     mResponseHead->ContentType(contentType);
 
-    if (contentType.Equals("multipart/x-mixed-replace"_ns)) {
+    if (contentType.Equals("multipart/x-mixed-replace"_ns) &&
+        ((mLoadInfo->GetExternalContentPolicyType() !=
+          ExtContentPolicyType::TYPE_DOCUMENT) ||
+         StaticPrefs::network_multipart_mixed_replace_enabled_for_document())) {
       nsCOMPtr<nsIStreamConverterService> convServ(
           do_GetService("@mozilla.org/streamConverters;1", &rv));
       if (NS_SUCCEEDED(rv)) {

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,8 @@`
`65`	`65`	`}`
`66`	`66`
`67`	`67`	`// If Fission is disabled, the pref is no-op.`
`68`		`-SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true]]}, () => {`
	`68`	`+SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true],`
	`69`	`+ ["network.multipart-mixed-replace.enabled_for_document", true]]}, () => {`
`69`	`70`	`// Have to open a new window, since there's no bfcache in subframes`
`70`	`71`	`window.open("file_bug660404-1.html", "", "noopener");`
`71`	`72`	`});`