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Title: "Print window" menu on IDLE aborts whole application
Type: behavior Stage: resolved
Components: IDLE Versions: Python 3.2, Python 3.3
Status: closed Resolution: fixed
Dependencies: 15392 Superseder:
Assigned To: Nosy List: BreamoreBoy, ggenellina, kbk, lukasz.langa, python-dev, terry.reedy
Priority: normal Keywords:

Created on 2011-06-07 06:16 by ggenellina, last changed 2022-04-11 14:57 by admin. This issue is now closed.

Messages (7)
msg137789 - (view) Author: Gabriel Genellina (ggenellina) Date: 2011-06-07 06:16
On Windows, IDLE closes all open windows and exits completely, without any error message, when selecting the "Print window" menu command.

Starting IDLE from inside a console, one can see the error message:

Exception in Tkinter callback
Traceback (most recent call last):
  File "D:\apps\python32\lib\tkinter\", line 1399, in __call__
    return self.func(*args)
  File "D:\apps\python32\lib\idlelib\", line 453, in print_window
    command = idleConf.GetOption('main','General','print-command-win')
  File "D:\apps\python32\lib\idlelib\", line 245, in GetOption
    type=type, raw=raw)
  File "D:\apps\python32\lib\idlelib\", line 54, in Get
    return self.get(section, option, raw=raw)
  File "D:\apps\python32\lib\", line 789, in get
  File "D:\apps\python32\lib\", line 391, in before_get
    self._interpolate_some(parser, option, L, value, section, defaults, 1)
  File "D:\apps\python32\lib\", line 440, in _interpolate_some
    "found: %r" % (rest,))
configparser.InterpolationSyntaxError: '%' must be followed by '%' or '(', found
: '%s'

It is trying to read this entry from the config-main.def file:

print-command-posix=lpr %s
print-command-win=start /min notepad /p %s

For a ConfigParser file, those %s should be %%s instead. Previous IDLE versions (2.7 and 3.1) read the same entry without problem; I suspect they were using a RawConfigParser or processing the entry in a different way.

As a workaround, replacing %s with %%s in config-main.def is enough, until the code gets fixed.
msg137790 - (view) Author: Gabriel Genellina (ggenellina) Date: 2011-06-07 06:18
Note: There is a much bigger problem here: IDLE should not abort abruptly in such cases, without any error indication.
msg137823 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2011-06-07 13:21
New changeset 0aa3064d1cef by Łukasz Langa in branch '3.2':
#12274: use proper escaping for % in IDLE config.

New changeset b410d013e7a8 by Łukasz Langa in branch 'default':
#12274: use proper escaping for % in IDLE config (merged from 3.2).
msg137825 - (view) Author: Łukasz Langa (lukasz.langa) * (Python committer) Date: 2011-06-07 13:26
In 3.2 configparser started validating syntax in interpolation-aware parsers by default. I fixed the configuration.

It's unfortunate this configuration error hasn't been caught before in testing. We need a unit test for broken configuration and a change in IDLE so that it doesn't silently crash when configuration is invalid.
msg220036 - (view) Author: Mark Lawrence (BreamoreBoy) * Date: 2014-06-08 14:59
Can this be closed as a patch has been committed and the unittest framework was created on issue15392 ?
msg220054 - (view) Author: Terry J. Reedy (terry.reedy) * (Python committer) Date: 2014-06-08 20:17
This issue needs a unittest test added within the framework. I opened #21696 as a dependency. Since configx.def files can be edited, and, I believe, at least one is intended to be edited, configHandler should perhaps catch exceptions and display in a messagebox. But unless Idle could continue after that, that might wait for the general fix, which is another issue.
msg228257 - (view) Author: Terry J. Reedy (terry.reedy) * (Python committer) Date: 2014-10-02 20:56
Closing since the immediate problem has been fixed and there is a reference to this in #21696
Date User Action Args
2022-04-11 14:57:18adminsetgithub: 56483
2016-10-05 10:26:41berker.peksagsetstatus: open -> closed
stage: test needed -> resolved
2014-10-02 20:56:09terry.reedysetresolution: fixed
dependencies: - Idle: test configuration files
messages: + msg228257
2014-06-08 20:17:25terry.reedysetdependencies: + Idle: test configuration files
messages: + msg220054
2014-06-08 14:59:01BreamoreBoysetnosy: + terry.reedy, BreamoreBoy
messages: + msg220036
2012-11-18 23:28:00roger.serwysetdependencies: + Create a unittest framework for IDLE
2011-06-07 13:26:41lukasz.langasetversions: + Python 3.3
nosy: + kbk

messages: + msg137825

stage: test needed
2011-06-07 13:21:46python-devsetnosy: + python-dev
messages: + msg137823
2011-06-07 12:46:18r.david.murraysetnosy: + lukasz.langa
2011-06-07 06:18:18ggenellinasetmessages: + msg137790
2011-06-07 06:16:07ggenellinacreate