Virtual Me2Me: Redirect stdin of Xsession to /dev/null.

remoting/tools/me2me_virtual_host.py

 #!/usr/bin/env python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Virtual Me2Me implementation.  This script runs and manages the processes
 # required for a Virtual Me2Me desktop, which are: X server, X desktop
 # session, and Host process.
 # This script is intended to run continuously as a background daemon
 # process, running under an ordinary (non-root) user account.
@@ skipping 236 matching lines @@
       if retcode == 0:
         break
       time.sleep(0.5)
     if retcode != 0:
       raise Exception("Could not connect to Xvfb.")
     else:
       logging.info("Xvfb is active.")
 
   def launch_x_session(self):
     # Start desktop session
+    # The /dev/null input redirection is necessary to prevent Xsession from
+    # reading from stdin.  If this code runs as a shell background job in a
+    # terminal, any reading from stdin causes the job to be suspended.
+    # Daemonization would solve this problem by separating the process from the
+    # controlling terminal.
     session_proc = subprocess.Popen("/etc/X11/Xsession",
+                                    stdin=open("/dev/null", "r"),
                                     cwd=os.environ["HOME"],
                                     env=self.child_env)
     if not session_proc.pid:
       raise Exception("Could not start X session")
 
   def launch_host(self):
     # Start remoting host
     command = locate_executable(REMOTING_COMMAND)
     self.host_proc = subprocess.Popen(command, env=self.child_env)
     if not self.host_proc.pid:
@@ skipping 40 matching lines @@
       logging.info("X server process terminated with code %d", status)
       break
 
     if pid == desktop.host_proc.pid:
       logging.info("Host process terminated, relaunching")
       desktop.launch_host()
 
 if __name__ == "__main__":
   logging.basicConfig(level=logging.DEBUG)
   sys.exit(main())