[ZODB-Dev] More ZODB POSKeyErrors with 2.6.0

[Jeremy Hylton]

>>>>> "TD" == Toby Dickenson <tdickenson@geminidataloggers.com> writes:

  CW> What does this mean?
  >>
  >> I just realized that this is probably a George Bailey object.
  >> That is, an undo or abort version undid the object creation.  So
  >> the object exists in the index, but is not loadable from the
  >> current state of the database.

  TD> If there any other case in which a back pointer can be zero? I
  TD> dont think so, but Im not sure.

Same here: I don't think so, but I'm not positive.

  TD> If this is true then FileStorage could raise a
  TD> POSGeorgeBaileyKeyError at this point, and avoid this confusion.

I don't have any qualms about calling it a George Bailey error in a
comment in the code or checkin message, but I don't want to expose
cute names to users.  Perhaps POSUncreationKeyError would be an okay
name, but it doesn't seem like it adds very much value.  It seems
unlikely that any user would care about the difference between the two
kinds of key errors.

Jeremy