job control command "%" no longer works

[Robert Haas]

So, apparently, sometime between bash-2.05a and bash-3.0, a change was made
to the job control commands. It used to be the case that typing "%" on a
line by itself would foreground the most recent job, just as if you had
typed "fg" or "%+". In bash-3.0, this prints the error message:

bash: fg: %: no such job

I'm not exactly sure what this means. If I type "%v", it refers to the
unique job whose command name starts with "v", so at a minimum it seems like
"%" ought to refer to the unique job in existence (since the empty string is
a prefix of every string) and produce an "ambiguous job spec" error if there
is more than one - but it doesn't work that way.

It's possible that "%" now means nothing at all, but even if it does have
some designated meaning, it would be much better, in my opinion, to restore
the historical behavior of referring to the most recent job, since that
behavior is useful (at least if you happen to like it), and the current
behavior appears to be useless.

...Robert