--- /Python-3.5.2/Lib/pty.py	2016-06-25 23:38:36.000000000 +0200
+++ pty.py	2016-12-23 14:47:19.229571369 +0100
@@ -144,6 +144,11 @@
             data = stdin_read(STDIN_FILENO)
             if not data:
                 fds.remove(STDIN_FILENO)
+                # STDIN is gone. When having attached this to a `nc -e` and the
+                # client disconnects, we want to make sure that we will not
+                # leave a process hanging around forever but we want to
+                # terminate at some point. This is basically a broken pipe.
+                return
             else:
                 _writen(master_fd, data)
 
@@ -154,6 +159,7 @@
     pid, master_fd = fork()
     if pid == CHILD:
         os.execlp(argv[0], *argv)
+        assert False, "unreachable or exec failed"
     try:
         mode = tty.tcgetattr(STDIN_FILENO)
         tty.setraw(STDIN_FILENO)