diff --git a/netwerk/protocol/http/HttpBaseChannel.cpp b/netwerk/protocol/http/HttpBaseChannel.cpp
index d8749b6f8c48..15efdd51cf0f 100644
--- a/netwerk/protocol/http/HttpBaseChannel.cpp
+++ b/netwerk/protocol/http/HttpBaseChannel.cpp
@@ -3835,13 +3835,6 @@ already_AddRefed<nsILoadInfo> HttpBaseChannel::CloneLoadInfoForRedirect(
   // Reset our sandboxed null principal ID when cloning loadInfo for an
   // externally visible redirect.
   if (!isInternalRedirect) {
-    // If we've redirected from http to something that isn't, clear
-    // the "external" flag, as loads that now go to other apps should be
-    // allowed to go ahead and not trip infinite-loop protection
-    // (see bug 1717314 for context).
-    if (!aNewURI->SchemeIs("http") && !aNewURI->SchemeIs("https")) {
-      newLoadInfo->SetLoadTriggeredFromExternal(false);
-    }
     newLoadInfo->ResetSandboxedNullPrincipalID();
   }
 
diff --git a/uriloader/exthandler/HandlerService.js b/uriloader/exthandler/HandlerService.js
index 62f2982defda..168333251bfd 100644
--- a/uriloader/exthandler/HandlerService.js
+++ b/uriloader/exthandler/HandlerService.js
@@ -568,8 +568,6 @@ HandlerService.prototype = {
       for (let extension of storedHandlerInfo.extensions) {
         handlerInfo.appendExtension(extension);
       }
-    } else if (this._mockedHandler) {
-      this._insertMockedHandler(handlerInfo);
     }
   },
 
@@ -734,48 +732,6 @@ HandlerService.prototype = {
     }
     return "";
   },
-
-  _mockedHandler: null,
-  _mockedProtocol: null,
-
-  _insertMockedHandler(handlerInfo) {
-    if (handlerInfo.type == this._mockedProtocol) {
-      handlerInfo.preferredApplicationHandler = this._mockedHandler;
-      handlerInfo.possibleApplicationHandlers.insertElementAt(
-        this._mockedHandler,
-        0
-      );
-    }
-  },
-
-  // test-only: mock the handler instance for a particular protocol/scheme
-  mockProtocolHandler(protocol) {
-    if (!protocol) {
-      this._mockedProtocol = null;
-      this._mockedHandler = null;
-      return;
-    }
-    this._mockedProtocol = protocol;
-    this._mockedHandler = {
-      QueryInterface: ChromeUtils.generateQI([Ci.nsILocalHandlerApp]),
-      launchWithURI(uri, context) {
-        Services.obs.notifyObservers(uri, "mocked-protocol-handler");
-      },
-      name: "Mocked handler",
-      detailedDescription: "Mocked handler for tests",
-      equals(x) {
-        return x == this;
-      },
-      executable: Services.dirsvc.get("XCurProcD", Ci.nsIFile),
-      parameterCount: 0,
-      clearParameters() {},
-      appendParameter() {},
-      getParameter() {},
-      parameterExists() {
-        return false;
-      },
-    };
-  },
 };
 
 this.NSGetFactory = ComponentUtils.generateNSGetFactory([HandlerService]);
diff --git a/uriloader/exthandler/tests/mochitest/browser.ini b/uriloader/exthandler/tests/mochitest/browser.ini
index 1d0c5c52225b..255b57465ea1 100644
--- a/uriloader/exthandler/tests/mochitest/browser.ini
+++ b/uriloader/exthandler/tests/mochitest/browser.ini
@@ -56,8 +56,6 @@ support-files =
 support-files =
   file_external_protocol_iframe.html
 [browser_protocol_ask_dialog_external.js]
-support-files =
-  redirect_helper.sjs
 [browser_protocol_ask_dialog_permission.js]
 [browser_protocolhandler_loop.js]
 [browser_remember_download_option.js]
diff --git a/uriloader/exthandler/tests/mochitest/browser_protocol_ask_dialog_external.js b/uriloader/exthandler/tests/mochitest/browser_protocol_ask_dialog_external.js
index f2e714f682b1..e05d03836f66 100644
--- a/uriloader/exthandler/tests/mochitest/browser_protocol_ask_dialog_external.js
+++ b/uriloader/exthandler/tests/mochitest/browser_protocol_ask_dialog_external.js
@@ -7,17 +7,12 @@ let gHandlerService = Cc["@mozilla.org/uriloader/handler-service;1"].getService(
   Ci.nsIHandlerService
 );
 
-const TEST_PATH = getRootDirectory(gTestPath).replace(
-  "chrome://mochitests/content",
-  "http://example.com"
-);
-
 /**
  * Creates dummy protocol handler
  */
 function initTestHandlers() {
   let handlerInfoThatAsks = HandlerServiceTestUtils.getBlankHandlerInfo(
-    "local-app-test"
+    "should-ask"
   );
 
   let appHandler = Cc[
@@ -113,7 +108,7 @@ add_task(async function test_external_asks_anyway() {
     gBrowser,
     true
   );
-  let fakeCmdLine = makeCmdLineHelper("local-app-test:dummy");
+  let fakeCmdLine = makeCmdLineHelper("should-ask:dummy");
   cmdLineHandler.handle(fakeCmdLine);
   let dialog = await chooserDialogOpenPromise;
   ok(dialog, "Should have prompted.");
@@ -174,52 +169,3 @@ add_task(async function test_web_app_doesnt_ask() {
     dialogOpenListener
   );
 });
-
-add_task(async function external_https_redirect_doesnt_ask() {
-  // Listen for a dialog open and fail the test if it does:
-  let dialogOpenListener = () => ok(false, "Shouldn't have opened a dialog!");
-  document.documentElement.addEventListener("dialogopen", dialogOpenListener);
-  registerCleanupFunction(() =>
-    document.documentElement.removeEventListener(
-      "dialogopen",
-      dialogOpenListener
-    )
-  );
-
-  let initialTab = gBrowser.selectedTab;
-
-  gHandlerService.wrappedJSObject.mockProtocolHandler("local-app-test");
-  registerCleanupFunction(() =>
-    gHandlerService.wrappedJSObject.mockProtocolHandler()
-  );
-
-  // Set up a promise for an app to have launched with the right URI:
-  let loadPromise = TestUtils.topicObserved("mocked-protocol-handler");
-
-  // Load the URL:
-  const kURL = "local-app-test:redirect";
-  let cmdLineHandler = Cc["@mozilla.org/browser/final-clh;1"].getService(
-    Ci.nsICommandLineHandler
-  );
-  let fakeCmdLine = makeCmdLineHelper(
-    TEST_PATH + "redirect_helper.sjs?uri=" + encodeURIComponent(kURL)
-  );
-  cmdLineHandler.handle(fakeCmdLine);
-
-  // Check that the mock app was launched. If the dialog showed instead,
-  // the test will fail.
-  let [uri] = await loadPromise;
-  is(uri.spec, "local-app-test:redirect", "Should have seen correct URI.");
-  // We might have opened a blank tab, see bug 1718104 and friends.
-  if (gBrowser.selectedTab != initialTab) {
-    BrowserTestUtils.removeTab(gBrowser.selectedTab);
-  }
-
-  // We do this both here and in cleanup so it's easy to add tasks to this test,
-  // and so we clean up correctly if the test aborts before we get here.
-  document.documentElement.removeEventListener(
-    "dialogopen",
-    dialogOpenListener
-  );
-  gHandlerService.wrappedJSObject.mockProtocolHandler();
-});
diff --git a/uriloader/exthandler/tests/mochitest/redirect_helper.sjs b/uriloader/exthandler/tests/mochitest/redirect_helper.sjs
deleted file mode 100644
index 1d66c1e9316b..000000000000
--- a/uriloader/exthandler/tests/mochitest/redirect_helper.sjs
+++ /dev/null
@@ -1,12 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-"use strict";
-
-Cu.importGlobalProperties(["URLSearchParams"]);
-
-function handleRequest(request, response) {
-  response.setStatusLine(request.httpVersion, 302, "Moved Temporarily");
-  response.setHeader("Location", new URLSearchParams(request.queryString).get("uri"));
-}
-