Predicate / Column reference "remapping", anyone? (w.r.t DERBY-1633)

[Army <qo...@gmail.com>]

I've spent a lot of time trying to understand the problem reported in DERBY-1633 
and have just attached a description of the issue, along with a proposed fix, to 
that Jira entry.

The fix isn't ready for commit, though, because it includes some changes for 
predicate remapping that I don't fully understand.  The changes resolve the 
regression and pass all of my tests, but I haven't quite been able to nail down 
*why* these particular remapping changes are necessary.

I'm still investigating this and hope to know more shortly, but in the meantime 
I thought I'd ask if anyone out there is familiar with predicate "remapping" and 
can perhaps help me see the justification for the changes I've made (that sounds 
weird, I know, but so it goes).  My questions are described in section V of the 
DERBY-1633.html document attached to DERBY-1633.

It is perhaps a long shot, but any feedback/comments could prove useful in 
resolving this blocker regression...

Thanks,
Army