threads_init not always present in gi bindings

[itamar]

Jessica reported the following:

$ python -c "import twisted; print twisted.__version__; from twisted.internet import gtk3reactor"
 12.0.0+r34756
 Traceback (most recent call last):
   File "<string>", line 1, in <module>
   File "twisted/internet/gtk3reactor.py", line 22, in <module>
     from twisted.internet import gireactor
   File "twisted/internet/gireactor.py", line 53, in <module>
     _oldGiInit()
   File "twisted/internet/gireactor.py", line 42, in _oldGiInit
     GLib.threads_init()
   File "/usr/lib/python2.7/dist-packages/gi/module.py", line 268, in __getattr__
     return getattr(self._introspection_module, name)
   File "/usr/lib/python2.7/dist-packages/gi/module.py", line 101, in __getattr__
     self.__name__, name))
 AttributeError: 'gi.repository.GLib' object has no attribute 'threads_init'

[itamar]

What OS was this? What version of pygobject?

[jesstess]

This is Ubuntu Natty:

$ apt-cache show python-gobject | grep Version
Version: 2.28.3-1ubuntu1
Version: 2.28.3-1ubuntu1.1
$ uname -a
Linux kid-charlemagne 2.6.38-13-generic #53-Ubuntu SMP Mon Nov 28 19:33:45 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
$ cat /etc/issue
Ubuntu 11.04 \n \l

[itamar]

AFAICT it just doesn't exist in that version. hasattr() time!

[itamarst]

(In [35156]) Branching to 'old-gi-5790'

[itamar]

I will do this as part of #5676, since otherwise the fixes will conflict.

[itamarst]

(In [35285]) Merge pygtkcompat-5676: Better support for newer and older gi versions.

Author: itamar Review: jesstess Fixes: #5676, #5790

Work with old versions of gi that didn't wrap enable_threads(), and with newer versions that have the gi.pygtkcompat compatability layer.