Issue 23792: help crash leaves terminal in echo off mode (original) (raw)

Issue23792

Created on 2015-03-27 17:09 by RusiMody, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
keyboardinterrupt_in_pydoc_pager.patch r.david.murray,2015-03-27 19:08 review
keyboardinterrupt_in_pydoc_pager.patch r.david.murray,2015-03-27 19:35 review
interrupt.patch martin.panter,2015-03-29 23:47 review
catch_additional_interrupt.patch r.david.murray,2015-03-30 00:15 review
Messages (20)
msg239417 - (view) Author: Rusi (RusiMody) Date: 2015-03-27 17:09
Start python3.4 Do help(something) which invokes the pager Ctrl-C A backtrace results and after that the terminal is in raw mode even after exiting python [python 3.4 under debian testing with xfce4]
msg239420 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-27 17:37
I can't reproduce this. Maybe it is a debian bug?
msg239422 - (view) Author: Berker Peksag (berker.peksag) * (Python committer) Date: 2015-03-27 17:50
This looks like a duplicate of issue 21398. I can reproduce it with Python 3.4.1 (compiled myself) on Ubuntu 12.04. >>> help(str) Ctrl-C :Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.4/_sitebuiltins.py", line 103, in __call__ return pydoc.help(*args, **kwds) File "/usr/local/lib/python3.4/pydoc.py", line 1817, in __call__ self.help(request) File "/usr/local/lib/python3.4/pydoc.py", line 1867, in help else: doc(request, 'Help on %s:', output=self._output) File "/usr/local/lib/python3.4/pydoc.py", line 1603, in doc pager(render_doc(thing, title, forceload)) File "/usr/local/lib/python3.4/pydoc.py", line 1411, in pager pager(text) File "/usr/local/lib/python3.4/pydoc.py", line 1431, in return lambda text: pipepager(text, 'less') File "/usr/local/lib/python3.4/pydoc.py", line 1453, in pipepager pipe.close() File "/usr/local/lib/python3.4/os.py", line 957, in close returncode = self._proc.wait() File "/usr/local/lib/python3.4/subprocess.py", line 1565, in wait (pid, sts) = self._try_wait(0) File "/usr/local/lib/python3.4/subprocess.py", line 1513, in _try_wait (pid, sts) = _eintr_retry_call(os.waitpid, self.pid, wait_flags) File "/usr/local/lib/python3.4/subprocess.py", line 491, in _eintr_retry_call return func(*args) KeyboardInterrupt
msg239423 - (view) Author: Ezio Melotti (ezio.melotti) * (Python committer) Date: 2015-03-27 17:50
I can reproduce on Python 3 on Ubuntu 14.10. When I hit Ctrl+C I get: >>> help(range) ... | __hash__(self, /) Return hash(self). :Traceback (most recent call last): File "", line 1, in File "/home/wolf/dev/py/py3k/Lib/_sitebuiltins.py", line 103, in __call__ return pydoc.help(*args, **kwds) File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1833, in __call__ self.help(request) File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1886, in help else: doc(request, 'Help on %s:', output=self._output) File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1619, in doc pager(render_doc(thing, title, forceload)) File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1409, in pager pager(text) File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1431, in return lambda text: pipepager(text, 'less') File "/home/wolf/dev/py/py3k/Lib/pydoc.py", line 1455, in pipepager pipe.write(text) File "/home/wolf/dev/py/py3k/Lib/subprocess.py", line 900, in __exit__ self.wait() File "/home/wolf/dev/py/py3k/Lib/subprocess.py", line 1552, in wait (pid, sts) = self._try_wait(0) File "/home/wolf/dev/py/py3k/Lib/subprocess.py", line 1502, in _try_wait (pid, sts) = os.waitpid(self.pid, wait_flags) KeyboardInterrupt >>> If I keep pressing Enter the rest of the help gets printed. Once the pager is done, pressing enter doesn't go on a new line and the prompts (>>>) are printed one after the other on the same line. The same happens on my shell prompt once I exit from the interpreter. `reset` fixes it. On Python 2 Ctrl+C does nothing.
msg239426 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-27 18:25
I do see the anomalous behavior inside python, but on my gentoo system when I exit python the terminal is fine.
msg239427 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-27 19:08
The attached patch fixes the issue for me.
msg239428 - (view) Author: Ezio Melotti (ezio.melotti) * (Python committer) Date: 2015-03-27 19:11
Patch WFM too.
msg239429 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-27 19:19
The print of KeyboardInterrupt whould be dropped. less itself does nothing if you press ctl-c, and the pager is used when pydoc is called from the shell command line, and printing KeyboardInterrupt there just looks wrong.
msg239431 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-27 19:35
Updated patch.
msg239446 - (view) Author: Martin Panter (martin.panter) * (Python committer) Date: 2015-03-28 00:44
I suspect you also need ignore signals while piping data to the child process. Similar to how the POSIX system() call ignores SIGINT and SIGQUIT soon after spawning the child, until after the child has exited. Try with a large help text on Linux, like import _pyio help(_pyio) Also, Python 2 still gets interrupted for me, it is just that it doesn’t seem to happen immediately if it is up to the pipe.close() call.
msg239460 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-28 16:59
SIGINT *is* keyboard interrupt. Since less at least seems to ignore SIGQUIT I suppose also ignoring that would be reasonable, since the user (should) by analogy expect that behavior while the pager is active. Note, however, that the signals we are ignoring are in the parent process, not the child as is the case for system. So one can argue that letting the python process die when SIGQUIT is received would also be reasonable, and arguably is the less surprising option.
msg239511 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-03-29 19:20
New changeset 77c04e949b4b by R David Murray in branch '3.4': #23792: Ignore KeyboardInterrupt when the pydoc pager is active. https://hg.python.org/cpython/rev/77c04e949b4b New changeset fe0c830b43bb by R David Murray in branch 'default': Merge: #23792: Ignore KeyboardInterrupt when the pydoc pager is active. https://hg.python.org/cpython/rev/fe0c830b43bb
msg239512 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-29 19:21
I've committed the fix. If someone wants to argue in favor of also handling SIGQUIT, they can open a new issue.
msg239535 - (view) Author: Martin Panter (martin.panter) * (Python committer) Date: 2015-03-29 23:47
I don’t think SIGQUIT handling is a big problem. But even with the new change, it is still easy to screw up the terminal in many cases, so I wouldn’t say this is fixed yet. Steps for Python 3 in a small 80 × 25 terminal on Linux: * import _pyio; help(_pyio) * Hit Ctrl-C Steps for Python 2: * import _pyio; help(_pyio) * Hit Ctrl-C * Hit Space ten times to scroll down. Alternatively, hit Ctrl-C a second time. I am posting a quick patch which I think should fix this in Python 3 by deferring the traceback until after the child has finished. Another method is using the signal module like <https://github.com/vadmium/pacman-tools/blob/9ffdd88/roopwn#L976>, but that’s probably too platform-specific for the pydoc module.
msg239537 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-30 00:15
Here is a version that keeps things clean by not diplaying the traceback. The ctl-c does have an effect, but not a visible one unless one pays careful attention :)
msg239541 - (view) Author: Martin Panter (martin.panter) * (Python committer) Date: 2015-03-30 00:54
I think your patch should be fine for all practical cases I can think of.
msg239612 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-03-30 14:17
New changeset 7a5f30babc72 by R David Murray in branch '3.4': #23792: also catch interrupt around pipe.write. https://hg.python.org/cpython/rev/7a5f30babc72 New changeset 536c4f4acae1 by R David Murray in branch 'default': Merge: #23792: also catch interrupt around pipe.write. https://hg.python.org/cpython/rev/536c4f4acae1
msg239614 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-30 14:45
Yeah, someone could theoretically manage to hit ctl-c between the time the process is started and the call to pipe.write, or between it and the call to wait, but I don't think those very-low-probability events are worth worrying about.
msg246845 - (view) Author: (swanson) Date: 2015-07-17 07:38
Changing the title in case anyone else is looking for this bug. This is not raw mode. It's just that echo is turned off. It is sufficient to type (invisibly, of course): stty echo to resume normal use of the terminal.
msg246853 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-07-17 14:03
Well, not exactly. While the title was inaccurate, the real problem was the management of the subprocess, not what mode the terminal was in.
History
Date User Action Args
2022-04-11 14:58:14 admin set github: 67980
2015-07-17 14:03:39 r.david.murray set messages: +
2015-07-17 07:38:40 swanson set nosy: + swansonmessages: + title: help crash leaves terminal in raw mode -> help crash leaves terminal in echo off mode
2015-03-30 14:45:41 r.david.murray set messages: +
2015-03-30 14:17:56 python-dev set messages: +
2015-03-30 00:54:42 martin.panter set messages: +
2015-03-30 00:15:59 r.david.murray set files: + catch_additional_interrupt.patchmessages: +
2015-03-29 23:47:50 martin.panter set files: + interrupt.patchmessages: +
2015-03-29 19:21:10 r.david.murray set status: open -> closedresolution: fixedmessages: + stage: commit review -> resolved
2015-03-29 19:20:15 python-dev set nosy: + python-devmessages: +
2015-03-28 16:59:52 r.david.murray set messages: +
2015-03-28 00:44:33 martin.panter set nosy: + martin.pantermessages: +
2015-03-27 19:35:14 r.david.murray set stage: patch review -> commit review
2015-03-27 19:35:03 r.david.murray set files: + keyboardinterrupt_in_pydoc_pager.patchmessages: +
2015-03-27 19:19:55 r.david.murray set messages: +
2015-03-27 19:11:23 ezio.melotti set messages: + stage: patch review
2015-03-27 19:08:52 r.david.murray set files: + keyboardinterrupt_in_pydoc_pager.patchkeywords: + patchmessages: +
2015-03-27 18:25:04 r.david.murray set messages: +
2015-03-27 17:50:51 ezio.melotti set versions: + Python 3.5nosy: + ezio.melottimessages: + type: crash -> behavior
2015-03-27 17:50:14 berker.peksag set nosy: + berker.peksagmessages: +
2015-03-27 17:37:17 r.david.murray set nosy: + r.david.murraymessages: +
2015-03-27 17:09:23 RusiMody create