Hello,

The recipe:

1. emacs -Q
2. Create a remote python file and start the remote python shell, e.g.
   M-x find-file /ssh:server:/tmp/test.py
   M-x run-python
3. Insert the following code in test.py and press C-c C-c to send it
   to the python shell:

   def f():
       breakpoint()
       return 1

4. Execute f() in the python shell to trigger the pdb

Result: Emacs tries to open /ssh:server:/ssh:server:/tmp/test.py
instead of /ssh:server:/tmp/test.py.

The reason is the filename set by python-shell-send-string may be
remote. The attached patch fixes the issue.

--
Liu Hui