Readline: how to resurrect an old RCR?


I'm about putting together a completion for irb which rocks. More
concretely, does context sensitive completion (filename completion
within a string, method name/variable completion elsewhere.

Very soon I got to the point that for this I'd need to acces the whole
line buffer from the completion proc. I looked around how to do this,
and soon I found the following among the old Rubygarden RCRs:

It's just about this thing, and also it gives a link to a ruby-talk post
with the right patch:

But it seems this RCR hasn't been reposted to RCRchive, so this nice
initiative got stalled. It would be nice to resurrect it.

What can be done? Should I myself re-submit the RCR? Or shall I just
drop a note to ruby-core that there is this patch, what do they think
about that?

The solution proposed there breaks backward compatibility, that's true
(although it's easy to fix): it makes one-argument completion procs cry.
This is a problem only if some package is not in the core ruby
distribution (as those can changed accordingly).

By the way, is there any readline-using application apart from irb?