(character) Conversion error (in vi) ?

[Yuri Pankov]

Ronald F. Guilmette wrote:
> Ever since my last system upgrade, some months ago now, vi has been
> behaving badly/differently.  Sometimes it gets a bee in its bonnet
> over something that, I guess, it is trying to interpret as a (malformed?)
> Unicode or utf-8 character or something, and in such cases it refuses
> to allow me to edit the file in question.
> 
> How can I return it to the old/prior behavior, under which it could
> tolerate any old sequence of eight bit bytes without having a hissy
> fit?
> 
> There must be some option to tell it "don't do that", yes?  (For the
> life of me, I don't know why the old/prior behavior wasn't maintained
> as the default behavior.  But I wonder the same thing about a *lot*
> of different software "upgrades".)

I'm interested in more details on this as I could be somewhat involved 
(see PR 202290).  What release did you upgrade from/to?  Could you 
provide a simple test case that shows the issue?