[issue24951] Idle test_configdialog fails on Fedora 23, 3.6

[Terry J. Reedy]

New submission from Terry J. Reedy:

In response to my python-list request for testing tkinter/idle on linux, Petr wrote

On Fedora 21, the tests pass (Python 3.4.1 and latest dev version).

On Fedora 23, I see:

$ python3 -V
Python 3.4.3 <tests pass>

$ ./python -V
Python 3.6.0a0
$ ./python -m test -ugui test_tk test_ttk_guionly test_idle
[1/3] test_tk
[2/3] test_ttk_guionly
[3/3] test_idle
test test_idle failed -- Traceback (most recent call last):
  File "/home/pviktori/dev/cpython/Lib/idlelib/idle_test/test_configdialog.py",
line 27, in test_dialog
    d=ConfigDialog(self.root, 'Test', _utest=True)
  File "/home/pviktori/dev/cpython/Lib/idlelib/configDialog.py", line
71, in __init__
    self.LoadConfigs()
  File "/home/pviktori/dev/cpython/Lib/idlelib/configDialog.py", line
1078, in LoadConfigs
    self.LoadFontCfg()
  File "/home/pviktori/dev/cpython/Lib/idlelib/configDialog.py", line
980, in LoadFontCfg
    self.SetFontSample()
  File "/home/pviktori/dev/cpython/Lib/idlelib/configDialog.py", line
858, in SetFontSample
    self.labelFontSample.config(font=newFont)
  File "/home/pviktori/dev/cpython/Lib/tkinter/__init__.py", line
1330, in configure
    return self._configure('configure', cnf, kw)
  File "/home/pviktori/dev/cpython/Lib/tkinter/__init__.py", line
1321, in _configure
    self.tk.call(_flatten((self._w, cmd)) + self._options(cnf))
_tkinter.TclError: expected integer but got ""

2 tests OK.
1 test failed:
    test_idle

Tk version: 8.6.4
---------------------------------------

----------
messages: 249275
nosy: encukou, markroseman, serhiy.storchaka, terry.reedy
priority: normal
severity: normal
stage: test needed
status: open
title: Idle test_configdialog fails on Fedora 23, 3.6
type: behavior
versions: Python 3.6

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue24951>
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