[ZODB-Dev] Latest news: core dump with small change to POSException.py

[Jeremy Hylton]

>>>>> "GW" == Greg Ward <gward@mems-exchange.org> writes:

  GW> On 25 September 2001, Jeremy Hylton said:
  >> One of the problems is that _p_resolveConflict() is C code that
  >> raises a ConflictError and passes it four arguments.  When the
  >> exception is actually caught in the interpreter and turned into
  >> an exception object, the call to ConflictError raises a
  >> TypeError.  After your patch, ConflictError only takes one
  >> argument, but it's called with four.  PyErr_NormalizeException()
  >> returnes normally, but with the bare except it dumps core.

  GW> Verrry interesting!  Sounds like it just might be a Python bug
  GW> after all.

And, lo, it is!

It's a fairly obscure problem that occurs exactly because the
exception is set in C and the attempt to construct the exception
instance fails before any Python code is executed.  I think I can fix
it, but I think the proper forum for further discussion of the bug is
python-dev.

It means that the ConflictError changes need to be prepared to deal
with the arguments passed in C code.  We'll need to check all the Zope
C code for PyErr_SetObject() where the first arg points to
ConflictError.

Jeremy