keyboardinterrupt crashes gtk gui when gtk.set_interactive is not available

[juliantaylor]

older gtk versions do not have gtk.set_interactive available which causes ipython to "use our own ctypes version":
IPython/lib/inputhook.py

240         import gtk
241         try:
242             gtk.set_interactive(True)
243             self._current_gui = GUI_GTK
244         except AttributeError:
245             # For older versions of gtk, use our own ctypes version
246             from IPython.lib.inputhookgtk import inputhook_gtk
247             self.set_inputhook(inputhook_gtk)
248             self._current_gui = GUI_GTK

this alternative does not handle keyboard interrupts well:

# make ipython use alternative, e.g. by using old gtk version or by editing:
# sed -i -e "s/gtk.set_interactive/gtk.garrbage/" IPython/lib/inputhook.py

ipython --pylab="gtk"
IN[1]: ^C
KeyboardInterrupt    Python 2.7.2+: /home/jtaylor/chroots/python/bin/python
                                                   Thu Sep 29 23:56:04 2011
A problem occured executing Python code.  Here is the sequence of function
calls leading up to the error, with the most recent (innermost) call last.
/home/jtaylor/chroots/python/_ctypes/callbacks.c in 'calling callback function'()

/home/jtaylor/chroots/python/lib/python2.7/site-packages/IPython/lib/inputhookgtk.pyc in inputhook_gtk()
     18 
     19 import sys
     20 import gtk, gobject
     21 
     22 #-----------------------------------------------------------------------------
     23 # Code
     24 #-----------------------------------------------------------------------------
     25 
     26 
     27 def _main_quit(*args, **kwargs):
     28     gtk.main_quit()
     29     return False
     30 
     31 def inputhook_gtk():
     32     gobject.io_add_watch(sys.stdin, gobject.IO_IN, _main_quit)
---> 33     gtk.main()
     34     return 0
     35 

KeyboardInterrupt: 

**********************************************************************

Oops, ipython crashed. We do our best to make it stable, but...

[minrk]

Sometimes we need to double-catch interrupts with these gui event loops.

How did you encounter this? PyGTK 2.15.0 (I believe the first to include set_interactive) was released in 05/2009, which is rather old.

[juliantaylor]

Most still supported distributions should have newer versions, but unfortunately I currently have to use a fedora 11 machine which has pygtk 2.14 :(

[cboos]

The "Oops, ipython crashed." seen above most certainly expands to:

...
Original exception was:
Traceback (most recent call last):
  File "_ctypes/callbacks.c", line 313, in 'calling callback function'
  ...

i.e. one can't raise (or let go through) an exception from a ctypes callback, inputhook_gtk here.
So at a minimum, a try: ... except KeyboardInterrupt: pass should be added there.

[fperez]

@juliantaylor, since you're the only one to be able to test any fixes for this (I don't have a machine with a pygtk old enough to see it), we'll have to wait on you for a fix. You could try the try/except solution suggested above by @cboos; if it works for you go ahead and submit a PR for this. As long as it doesn't cause any problems with newer pygtks, we'll be happy to include the fix.

I'm retargetting for 0.13, b/c we're basically at the point of releasing 0.12 and I only want to focus on critical issues that absolutely must go in before release, this doesn't quite meet that threshold.

[juliantaylor]

has this issue been fixed in HEAD? I can't reproduce it anymore, but ctrl+c also does not work at all anymore

[juliantaylor]

the crash was fixed with 0fc80df
that ctrl+c does not work at all like before is probably a different issue (or intentional change ?) as it affects also other backends on more up to date systems.

[fperez]

Wow, since when did Ctrl-C stop working??? That's a huge regression, and most certainly a blocker. I'll open a separate issue for that.

[fperez]

We got distracted by #1157, but it sounds like this can be closed. Is that right @juliantaylor? I have no way of reproducing this, and you said you weren't seeing it either. In the interest of expedient triage I'm closing it now, please ping for a reopen if you find evidence it's still an issue.