Patch #838546: Make terminal become controlling in pty.fork().

Lib/pty.py

@@ -118,6 +118,10 @@ def fork():
         if (slave_fd > STDERR_FILENO):
             os.close (slave_fd)
 
+        # Explicitly open the tty to make it become a controlling tty.
+        tmp_fd = os.open(os.ttyname(STDOUT_FILENO), os.O_RDWR)
+        os.close(tmp_fd)
+
     # Parent and child process.
     return pid, master_fd
 

Misc/NEWS

@@ -70,6 +70,8 @@ Core and builtins
 Extension Modules
 -----------------
 
+- Patch #838546: Make terminal become controlling in pty.fork()
+
 - Patch #1560695: Add .note.GNU-stack to ctypes' sysv.S so that
   ctypes isn't considered as requiring executable stacks.