Bug 1909081 - Clear cached method upon redirect r=willdurand

Differential Revision: https://phabricator.services.mozilla.com/D217399

toolkit/components/extensions/test/xpcshell/test_ext_dnr_across_redirects.js

@@ -0,0 +1,105 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const server = createHttpServer({ hosts: ["example.com", "redir"] });
+
+server.registerPathHandler("/redirect_from_303", (req, res) => {
+  res.setStatusLine(req.httpVersion, 303, "See Other");
+  res.setHeader("Location", "/redirect_to?303");
+});
+
+server.registerPathHandler("/redirect_from_307", (req, res) => {
+  res.setStatusLine(req.httpVersion, 307, "Temporary Redirect");
+  res.setHeader("Location", "/redirect_to?307");
+});
+
+server.registerPathHandler("/redirect_to", (req, res) => {
+  info(`Received request: ${req.method} ${req.url}`);
+  // Return the method as seen by the server, so that the test can confirm that
+  // the method as seen by the server matches the method as seen by DNR.
+  res.setHeader("outcome", "server-" + req.method);
+});
+
+add_task(async function test_match_across_redirects() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      host_permissions: ["<all_urls>"],
+      permissions: ["declarativeNetRequestWithHostAccess"],
+    },
+    async background() {
+      await browser.declarativeNetRequest.updateSessionRules({
+        addRules: [
+          {
+            id: 1,
+            condition: {
+              requestMethods: ["get", "post"],
+              urlFilter: "/redirect_from",
+            },
+            action: {
+              type: "modifyHeaders",
+              responseHeaders: [
+                // Because the request is redirected, the fetch() caller should
+                // not observe this header:
+                { operation: "append", header: "outcome", value: "pre_redir" },
+              ],
+            },
+          },
+          {
+            id: 2,
+            // HTTP 302 and 303 should convert redirects to GET:
+            condition: {
+              requestMethods: ["get"],
+              urlFilter: "/redirect_to",
+            },
+            action: {
+              type: "modifyHeaders",
+              responseHeaders: [
+                { operation: "append", header: "outcome", value: "match_get" },
+              ],
+            },
+          },
+          {
+            // HTTP 307 should preserve HTTP method.
+            id: 3,
+            condition: {
+              requestMethods: ["post"],
+              urlFilter: "/redirect_to",
+            },
+            action: {
+              type: "modifyHeaders",
+              responseHeaders: [
+                { operation: "append", header: "outcome", value: "match_post" },
+              ],
+            },
+          },
+        ],
+      });
+
+      async function getOutcome(method, path) {
+        const url = `http://example.com${path}`;
+        const { headers } = await fetch(url, { method });
+        return headers.get("outcome");
+      }
+
+      // Regression test for bug 1909081:
+      browser.test.assertEq(
+        "server-GET, match_get",
+        await getOutcome("POST", "/redirect_from_303"),
+        "HTTP 303 changes POST to GET, and DNR should match GET"
+      );
+
+      browser.test.assertEq(
+        "server-POST, match_post",
+        await getOutcome("POST", "/redirect_from_307"),
+        "HTTP 307 keeps POST as POST, and DNR should match POST"
+      );
+
+      browser.test.sendMessage("done");
+    },
+  });
+  await extension.startup();
+  await extension.awaitMessage("done");
+  await extension.unload();
+});

toolkit/components/extensions/test/xpcshell/xpcshell-common.toml

@@ -212,6 +212,8 @@ skip-if = [
 
 ["test_ext_debugging_utils.js"]
 
+["test_ext_dnr_across_redirects.js"]
+
 ["test_ext_dnr_allowAllRequests.js"]
 
 ["test_ext_dnr_api.js"]

toolkit/components/extensions/webrequest/ChannelWrapper.cpp

@@ -189,8 +189,12 @@ already_AddRefed<ChannelWrapper> ChannelWrapper::GetRegisteredChannel(
 }
 
 void ChannelWrapper::SetChannel(nsIChannel* aChannel) {
+  // SetChannel is called when the channel changes, e.g. by redirects.
+  // NOTE: Redirect tracking depends on a webRequest listener (bug 1799118).
   detail::ChannelHolder::SetChannel(aChannel);
   ClearCachedAttributes();
+  // Method may change when the request is redirected with HTTP 301, 302, 303.
+  ChannelWrapper_Binding::ClearCachedMethodValue(this);
   ChannelWrapper_Binding::ClearCachedFinalURIValue(this);
   ChannelWrapper_Binding::ClearCachedFinalURLValue(this);
   mFinalURLInfo.reset();