Bug 1542316: Allow new instances to be launched if the path to the application bundle is different than currently running instances on macOS. r=spohl

toolkit/xre/nsNativeAppSupportCocoa.mm

@@ -67,7 +67,15 @@ void remoteClientNotificationCallback(CFNotificationCenterRef aCenter, void* aOb
   // Autorelease pool to prevent memory leaks, in case there is no outer pool.
   mozilla::MacAutoreleasePool pool;
   NSDictionary* userInfoDict = (__bridge NSDictionary*)aUserInfo;
-  if (userInfoDict && [userInfoDict objectForKey:@"commandLineArgs"]) {
+  if (userInfoDict && [userInfoDict objectForKey:@"commandLineArgs"] &&
+      [userInfoDict objectForKey:@"senderPath"]) {
+
+    NSString* senderPath = [userInfoDict objectForKey:@"senderPath"];
+    if (![senderPath isEqual:[[NSBundle mainBundle] bundlePath]]) {
+      // The caller is not the process at the same path as we are at. Skipping.
+      return;
+    }
+
     NSArray* args = [userInfoDict objectForKey:@"commandLineArgs"];
     nsCOMPtr<nsICommandLineRunner> cmdLine(new nsCommandLine());
 
@@ -201,16 +209,28 @@ NS_IMETHODIMP nsNativeAppSupportCocoa::Start(bool* _retval) {
   if (!shallProceedLikeNoRemote) {
     // We check for other running instances only if -no-remote was not specified.
     // The check is needed so the marAppApplyUpdateSuccess.js test doesn't fail on next call.
-    runningInstanceFound =
-        [[NSRunningApplication
-            runningApplicationsWithBundleIdentifier:[[NSBundle mainBundle] bundleIdentifier]]
-            count] > 1;
+    NSArray* appsWithMatchingId = [NSRunningApplication runningApplicationsWithBundleIdentifier:
+                                    [[NSBundle mainBundle] bundleIdentifier]];
+    NSString* currentAppBundlePath = [[NSBundle mainBundle] bundlePath];
+    NSRunningApplication* currentApp = [NSRunningApplication currentApplication];
+    for (NSRunningApplication* app in appsWithMatchingId) {
+      if ([currentAppBundlePath isEqual:[[app bundleURL] path]] &&
+          ![currentApp isEqual:app]) {
+        runningInstanceFound = YES;
+        break;
+      }
+    }
   }
 
   if (!shallProceedLikeNoRemote && !mozillaRestarting && runningInstanceFound) {
     // There is another instance of this app already running!
     NSArray* arguments = [[NSProcessInfo processInfo] arguments];
-    CFDictionaryRef userInfoDict = (__bridge CFDictionaryRef) @{@"commandLineArgs" : arguments};
+    NSString* senderPath = [[NSBundle mainBundle] bundlePath];
+    CFDictionaryRef userInfoDict = (__bridge CFDictionaryRef) @{@"commandLineArgs" :
+                                                                  arguments,
+                                                                @"senderPath":
+                                                                  senderPath
+                                                                };
 
     // This code is shared between Firefox, Thunderbird and other Mozilla products.
     // So we need a notification name that is unique to the product, so we