[macOS] Always execute editor instances using NSWorkspace to ensure a…

…pp window is registered and activated correctly.

platform/osx/os_osx.h

@@ -249,6 +249,7 @@ class OS_OSX : public OS_Unix {
 	virtual void get_fullscreen_mode_list(List<VideoMode> *p_list, int p_screen = 0) const;
 
 	virtual String get_executable_path() const;
+	virtual Error execute(const String &p_path, const List<String> &p_arguments, bool p_blocking = true, ProcessID *r_child_id = nullptr, String *r_pipe = nullptr, int *r_exitcode = nullptr, bool read_stderr = false, Mutex *p_pipe_mutex = nullptr);
 
 	virtual LatinKeyboardVariant get_latin_keyboard_variant() const;
 	virtual int keyboard_get_layout_count() const;

platform/osx/os_osx.mm

@@ -2955,6 +2955,60 @@ static int get_screen_index(NSScreen *screen) {
 	}
 }
 
+Error OS_OSX::execute(const String &p_path, const List<String> &p_arguments, bool p_blocking, ProcessID *r_child_id, String *r_pipe, int *r_exitcode, bool read_stderr, Mutex *p_pipe_mutex) {
+	if (@available(macOS 10.15, *)) {
+		NSString *nsappname = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleName"];
+		// If executable is bundled, always execute editor instances using NSWorkspace to ensure app window is registered and activated correctly.
+		if (p_path == get_executable_path() && nsappname != nil) {
+			if (p_blocking && r_pipe) {
+				ERR_FAIL_V_MSG(ERR_CANT_OPEN, "Cannot pipe stream from process running as app bundle.");
+			}
+			NSMutableArray *arguments = [[NSMutableArray alloc] init];
+			for (const List<String>::Element *E = p_arguments.front(); E; E = E->next()) {
+				[arguments addObject:[NSString stringWithUTF8String:E->get().utf8().get_data()]];
+			}
+			NSWorkspaceOpenConfiguration *configuration = [[NSWorkspaceOpenConfiguration alloc] init];
+			[configuration setArguments:arguments];
+			[configuration setCreatesNewApplicationInstance:YES];
+			__block dispatch_semaphore_t lock = dispatch_semaphore_create(0);
+			__block Error err = ERR_TIMEOUT;
+			__block pid_t pid = 0;
+			[[NSWorkspace sharedWorkspace] openApplicationAtURL:[[NSBundle mainBundle] bundleURL]
+												  configuration:configuration
+											  completionHandler:^(NSRunningApplication *app, NSError *error) {
+												  if (error) {
+													  err = ERR_CANT_FORK;
+													  NSLog(@"Failed to execute: %@", error.localizedDescription);
+												  } else {
+													  pid = [app processIdentifier];
+													  err = OK;
+												  }
+												  dispatch_semaphore_signal(lock);
+											  }];
+			dispatch_semaphore_wait(lock, dispatch_time(DISPATCH_TIME_NOW, 20000000000)); // 20 sec timeout, wait for app to launch.
+			dispatch_release(lock);
+
+			if (err == OK) {
+				if (p_blocking) {
+					int status;
+					waitpid(pid, &status, 0);
+					if (r_exitcode) {
+						*r_exitcode = WIFEXITED(status) ? WEXITSTATUS(status) : status;
+					}
+				} else if (r_child_id) {
+					*r_child_id = (ProcessID)pid;
+				}
+			}
+
+			return err;
+		} else {
+			return OS_Unix::execute(p_path, p_arguments, p_blocking, r_child_id, r_pipe, r_exitcode, read_stderr, p_pipe_mutex);
+		}
+	} else {
+		return OS_Unix::execute(p_path, p_arguments, p_blocking, r_child_id, r_pipe, r_exitcode, read_stderr, p_pipe_mutex);
+	}
+}
+
 // Returns string representation of keys, if they are printable.
 //
 static NSString *createStringForKeys(const CGKeyCode *keyCode, int length) {