1 files changed, 71 insertions, 0 deletions
diff --git a/comm/mail/components/extensions/processScript.js b/comm/mail/components/extensions/processScript.js
new file mode 100644
index 0000000000..4b71e651a8
--- /dev/null
+++ b/comm/mail/components/extensions/processScript.js
@@ -0,0 +1,71 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Inject the |messenger| object as an alias to |browser| in all known contexts.
+// This script is injected into all processes.
+
+// This is a bit fragile since it uses monkeypatching. If a test fails, the best
+// way to debug is to search for Schemas.exportLazyGetter where it does the
+// injections, add |messenger| alias to those files until the test passes again,
+// and then find out why the monkeypatching is not catching it.
+
+const { ExtensionContent } = ChromeUtils.importESModule(
+  "resource://gre/modules/ExtensionContent.sys.mjs"
+);
+const { ExtensionPageChild } = ChromeUtils.importESModule(
+  "resource://gre/modules/ExtensionPageChild.sys.mjs"
+);
+const { ExtensionUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/ExtensionUtils.sys.mjs"
+);
+const { Schemas } = ChromeUtils.importESModule(
+  "resource://gre/modules/Schemas.sys.mjs"
+);
+
+let getContext = ExtensionContent.getContext;
+let initExtensionContext = ExtensionContent.initExtensionContext;
+let initPageChildExtensionContext = ExtensionPageChild.initExtensionContext;
+
+// This patches constructor of ContentScriptContextChild adding the object to
+// the sandbox.
+ExtensionContent.getContext = function (extension, window) {
+  let context = getContext.apply(ExtensionContent, arguments);
+  if (!("messenger" in context.sandbox)) {
+    Schemas.exportLazyGetter(
+      context.sandbox,
+      "messenger",
+      () => context.chromeObj
+    );
+  }
+  return context;
+};
+
+// This patches extension content within unprivileged pages, so an iframe on a
+// web page that points to a moz-extension:// page exposed via
+// web_accessible_content.
+ExtensionContent.initExtensionContext = function (extension, window) {
+  let context = extension.getContext(window);
+  Schemas.exportLazyGetter(window, "messenger", () => context.chromeObj);
+
+  return initExtensionContext.apply(ExtensionContent, arguments);
+};
+
+// This patches privileged pages such as the background script.
+ExtensionPageChild.initExtensionContext = function (extension, window) {
+  let retval = initPageChildExtensionContext.apply(
+    ExtensionPageChild,
+    arguments
+  );
+
+  let windowId = ExtensionUtils.getInnerWindowID(window);
+  let context = ExtensionPageChild.extensionContexts.get(windowId);
+
+  Schemas.exportLazyGetter(window, "messenger", () => {
+    let messengerObj = Cu.createObjectIn(window);
+    context.childManager.inject(messengerObj);
+    return messengerObj;
+  });
+
+  return retval;
+};