browser(firefox): close browser when pipe disconnects (#4437)

browser_patches/firefox/BUILD_NUMBER

@@ -1,2 +1,2 @@
-1206
-Changed: yurys@chromium.org Thu 12 Nov 2020 10:23:24 AM PST
+1207
+Changed: dgozman@gmail.com Fri Nov 13 14:41:15 PST 2020

browser_patches/firefox/juggler/components/juggler.js

@@ -79,6 +79,8 @@ CommandLineHandler.prototype = {
       loadFrameScript();
       dump(`Juggler listening on ws://127.0.0.1:${this._server.port}/${token}\n`);
     } else if (jugglerPipeFlag) {
+      let browserHandler;
+      let pipeStopped = false;
       const pipe = Cc['@mozilla.org/juggler/remotedebuggingpipe;1'].getService(Ci.nsIRemoteDebuggingPipe);
       const connection = {
         QueryInterface: ChromeUtils.generateQI([Ci.nsIRemoteDebuggingPipeClient]),
@@ -86,20 +88,28 @@ CommandLineHandler.prototype = {
           if (this.onmessage)
             this.onmessage({ data: message });
         },
+        disconnected() {
+          if (browserHandler)
+            browserHandler['Browser.close']();
+        },
         send(message) {
+          if (pipeStopped) {
+            // We are missing the response to Browser.close,
+            // but everything works fine. Once we actually need it,
+            // we have to stop the pipe after the response is sent.
+            return;
+          }
           pipe.sendMessage(message);
         },
       };
       pipe.init(connection);
       const dispatcher = new Dispatcher(connection);
-      const browserHandler = new BrowserHandler(dispatcher.rootSession(), dispatcher, targetRegistry, () => {
+      browserHandler = new BrowserHandler(dispatcher.rootSession(), dispatcher, targetRegistry, () => {
         if (silent)
           Services.startup.exitLastWindowClosingSurvivalArea();
-        // Send response to the Browser.close, and then stop in the next microtask.
-        Promise.resolve().then(() => {
-          connection.onclose();
-          pipe.stop();
-        });
+        connection.onclose();
+        pipe.stop();
+        pipeStopped = true;
       });
       dispatcher.rootSession().setHandler(browserHandler);
       loadFrameScript();

browser_patches/firefox/juggler/pipe/nsIRemoteDebuggingPipe.idl

@@ -8,6 +8,7 @@
 interface nsIRemoteDebuggingPipeClient : nsISupports
 {
   void receiveMessage(in AString message);
+  void disconnected();
 };
 
 [scriptable, uuid(b7bfb66b-fd46-4aa2-b4ad-396177186d94)]

browser_patches/firefox/juggler/pipe/nsRemoteDebuggingPipe.cpp

@@ -151,8 +151,13 @@ void nsRemoteDebuggingPipe::ReaderLoop() {
   std::vector<char> line;
   while (!m_terminated) {
     size_t size = ReadBytes(buffer.data(), bufSize, false);
-    if (!size)
+    if (!size) {
+      nsCOMPtr<nsIRunnable> runnable = NewRunnableMethod<>(
+          "nsRemoteDebuggingPipe::Disconnected",
+          this, &nsRemoteDebuggingPipe::Disconnected);
+      NS_DispatchToMainThread(runnable.forget());
       break;
+    }
     size_t start = 0;
     size_t end = line.size();
     line.insert(line.end(), buffer.begin(), buffer.begin() + size);
@@ -191,6 +196,12 @@ void nsRemoteDebuggingPipe::ReceiveMessage(const nsCString& aMessage) {
   }
 }
 
+void nsRemoteDebuggingPipe::Disconnected() {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread(), "Remote debugging pipe must be used on the Main thread.");
+  if (mClient)
+    mClient->Disconnected();
+}
+
 nsresult nsRemoteDebuggingPipe::SendMessage(const nsAString& aMessage) {
   MOZ_RELEASE_ASSERT(NS_IsMainThread(), "Remote debugging pipe must be used on the Main thread.");
   if (!mClient) {

browser_patches/firefox/juggler/pipe/nsRemoteDebuggingPipe.h

@@ -22,6 +22,7 @@ class nsRemoteDebuggingPipe final : public nsIRemoteDebuggingPipe {
  private:
   void ReaderLoop();
   void ReceiveMessage(const nsCString& aMessage);
+  void Disconnected();
   ~nsRemoteDebuggingPipe();
 
   RefPtr<nsIRemoteDebuggingPipeClient> mClient;