Backporting the PyCapsule object from 3.1 to 2.7.  I'll have a patch today.

All windows buildbots fail to compile:

http://www.python.org/dev/buildbot/all/builders/x86%20XP-4%20trunk
http://www.python.org/dev/buildbot/all/builders/x86%20XP-5%20trunk
http://www.python.org/dev/buildbot/all/builders/x86%20Windows7%20trunk

As Marc-André pointed out, you shouldn't have converted old uses of PyCObject. It breaks compatibility, and I don't think there's any point since 2.7 will probably be the last in the 2.x line.

(if you want to be perfectionist, you can have those modules provide both a PyCObject and a PyCapsule interface...)

PyCapsule comes from issues #5630 and #5872.

This is also (naturally) being discussed on python-dev.  I've posted a long message there about it; you can find that message here:

http://mail.python.org/pipermail/python-dev/2010-March/098904.html

I don't know whether it's best to conduct such a discussion here, in Python-Dev, or both.  I assumed Python-Dev is superior because more people will see it.  If it makes sense to move the discussion here we can move it.

Florent: that's because the Windows build projects don't build capsule.c.  I don't have an appropriate Windows development environment; I'll try to fix them by hand tonight, but if that doesn't work we'll have to call for help from some Windows core developer.

(adding myself to the nosy list as a Windows dev)

The PendingDeprecationWarning is still spit by the bsddb module.

$ ./python -Wd -m test.regrtest test_bsddb
test_bsddb
./Lib/importlib/__init__.py:37: PendingDeprecationWarning: The CObject type is marked Pending Deprecation in Python 2.7.  Please use capsule objects instead.
  __import__(name)h
1 test OK.

Yes.  I was told it was inappropriate for me to change the bsddb module, as it's independently maintained by Jesus Cea.  I sent Mr. Cea a patch last night; I hope he chooses to merge it soon.

Since CObjects are marked Pending Deprecation, and bsddb is using a CObject, this is correct behavior.

Were you mentioning it simply to bring it my attention, or am I missing something important?

Oh, and, last night I checked in r79590.  This is the checkin that ameliorates the backwards compatibility issues.  Specifically, I changed four things:

* PyCObject_AsVoidPtr() can now open capsules.  This addresses
  most of the remaining backwards-compatibility concerns about
  the conversion of Python 2.7 from CObjects to capsules.
* CObjects were marked Pending Deprecation.
* Documentation about this pending deprecation was added to
  cobject.h.
* The capsule source files were added to the legacy PC build
  processes.

(Someone had already added them to the current PC build process, a day or two after I committed the previous checkin.)

Sorry for forgetting to update the issue last night, but I was in a bit of a hurry to get this done before Benjamin cut 2.7b1.

Ok, I put Jésus in the nosy list.

It makes the test___all__ fail on trunk because it checks the warnings raised during import.

AFAIU, the patch is something like:

-#if (PY_VERSION_HEX < 0x03020000)
+#if (PY_VERSION_HEX < 0x02070000)

The patch is a bit more involved than that.  Capsules didn't exist in 3.0, and the bsddb module published a CObject in 3.1.  So bsddb must continue to use CObject for those two releases.

Therefore the patch to the line you were addressing looks like this:

-#if (PY_VERSION_HEX < 0x03020000)
+#if (PY_VERSION_HEX < ((PY_MAJOR_VERSION < 3) ? 0x02070000 : 0x03020000))

However, Jesus's use of capsules has a bug.  The capsule API requires that the string passed in to PyCapsule_New() must "outlive" the capsule; he's passing in a stack buffer.  So my patch also fixes that.

Finally my bsddb patch adds the appropriate text to the header file where it describes how to import the _bsddb C API object (CObject vs capsule).

FWIW, I want to close this issue soon.  How about I close it after 2.7b1 has been out for a week or so--assuming there aren't any new concerns regarding the capsule backport.

Marking closed, as promised; 2.7b1 has been out for nine days and there hasn't been a peep.  If new problems crop up from the capsule backport, please create a new issue and assign it to me.

For posterity: 2.7b1 shipped with a bsddb that still publishes a CObject.  This is the only CObject left in 2.7b1, and Python doesn't itself use that CObject for anything.  Therefore there are no CObject exploits left in pure Python 2.7b1.  I don't know if bsddb will switch to a capsule in a later Python 2.7 beta; that's up to Jesus and Benjamin and co.  But I suspect it won't.

For future reference:

http://mail.python.org/pipermail/python-committers/2010-April/000875.html

The final consensus was not to integrate bsddb Capsule for Python 2.7, since CObject is not actually deprecated in python 2.7.