test_doctest.py test_pdb_set_trace_nested():  A new test from Jim Fulton
showing that doctest's pdb.set_trace() support was dramatically broken.

doctest.py _OutputRedirectingPdb.trace_dispatch():  Return a local trace
function instead of (implicitly) None.  Else interaction with pdb was
bizarre, noticing only 'call' events.  Amazingly, the existing set_trace()
tests didn't care.
3 files changed