Gian-Carlo is right: I can modify the 2.6 tests in the same way as I described, and then I get the same error with python2.6.  So it seems that all of 2.6 was prone to the same issue, and it was never found, but went away in 2.7 accidentally.  That seems to mean that reverting 030e100f048a was not really necessary (beyond the issue with PyPy/Jython/IronPython).

According to http://bugs.python.org/issue23129 it was not a good idea to revert 030e100f048a.  But I'm surprized that the test added with 030e100f048a continues to pass with the revertion.  Maybe we should investigate why it does.  (Again, don't rely on me for that, because I don't know sqlite.)

If 030e100f048a stays in, I'll probably figure out a hack to avoid this pitfall with PyPy.