[New-bugs-announce] [issue8862] curses.wrapper does not restore terminal if curses.getkey() gets KeyboardInterrupt

[July Tikhonov]

New submission from July Tikhonov <july.tikh at gmail.com>:

Run test.py (below) in terminal, and interrupt it with Ctrl-C.

Result: terminal settings are not restored (checked with linux console and xterm, with Python 2.7 and 3.2).

# test.py
# Broke it with KeyboardInterrupt
import curses
def main(screen):
    k = screen.getkey()
curses.wrapper(main)
# Results are hardly readable due to the broken terminal.
# Something about KeyboardInterrupt

However, if getkey() is surrounded by try-except, behavior changes:

# test2.py
# Broke it with KeyboardInterrupt
import curses
def main2(screen):
    try:
        k = screen.getkey()
    except KeyboardInterrupt:
        raise
curses.wrapper(main2)
# Terminal is restored to its normal state.

In python3.2 test2.py results in traceback:

Traceback (most recent call last):
  File "test2.py", line 4, in main2
    k = screen.getkey()
_curses.error: no input

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "test2.py", line 7, in <module>
    curses.wrapper(main2)
  File "/usr/local/lib/python3.2/curses/wrapper.py", line 44, in wrapper
    return func(stdscr, *args, **kwds)
  File "test2.py", line 4, in main2
    k = screen.getkey()
KeyboardInterrupt


In 2.7 it results only in the latest part of traceback:

Traceback (most recent call last):
  File "test2.py", line 7, in <module>
    curses.wrapper(main2)
  File "/usr/local/lib/python2.7/curses/wrapper.py", line 44, in wrapper
    return func(stdscr, *args, **kwds)
  File "test2.py", line 4, in main2
    k = screen.getkey()
KeyboardInterrupt


The problem is that instead of a single KeyboardInterrupt, two exceptions are raised: KeyboardInterrupt and _curses.error('no input').

Possible solution is to suppress _curses.error in this case (since it is less relevant than KeyboardInterrupt, IMO).

----------
components: Library (Lib)
messages: 106799
nosy: july
priority: normal
severity: normal
status: open
title: curses.wrapper does not restore terminal if curses.getkey() gets KeyboardInterrupt
type: behavior
versions: Python 2.7, Python 3.2

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue8862>
_______________________________________