New submission from sping: Hi!
A college of mine ran into a bug with raw_input. We have a shell derived from stdlib module "cmd" here but the bug shows with plain raw_input, as well (see demo code). For the symptoms: the shell is executing commands from history that the user explicitly chose not to run. Since our shell does things like deallocation of LVM volumes, that behavior is rather troublesome :) How does it happen? * When pressing Ctrl+R, an incremental reverse history search is started. During that search, you normalled press Escape/Ctrl+J/Ctrl+G to end search or Return to pick a result. * When you press Ctrl+C though, the next call to the raw_input function believes to be in search mode still (while not showing "(reverse-i-search)" or indicating search some way). * Now when (entering some text and) pressing return now, the string last shown during incremental search is being return from raw_input (and executed in context of the cmd module). I have re-produced the issue with Python 2.7.3, 2.7.9, 3.2.3, 3.4.2. For a workaround, one can handle KeyboardInterrupt and internal adjust variable rl_readline_state of the C readline library. I'm attaching (a minimal bug demo and) the ctypes based workaround that works well over here. (The workaround demo also shows that readline state is not fully reset when Ctrl+C was pressed outside of search mode, since flag RL_STATE_DONE is not set after.) It would rock the house if this could be fixed in Python. I'm looking forward to your reply. Best, Sebastian ---------- components: Interpreter Core files: raw_input__workaround_demo.py messages: 243828 nosy: sping priority: normal severity: normal status: open title: raw_input function (with readline): Ctrl+C (during search mode but not only) leaves readline in broken state type: behavior versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5, Python 3.6 Added file: http://bugs.python.org/file39467/raw_input__workaround_demo.py _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue24266> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
