bug#16251: 24.3.50; `icomplete-mode' breaks my file opening now

[Stefan Monnier]

> I downloaded this build, and when `icomplete-mode' is on, with my setup
> it takes several seconds to gather the list of file candidates in my
> usual directory.

I just reverted icomplete-show-matches-on-no-input to nil, which I think
is the right default.  That it can take a long time to get the
completions is not in itself a bug.  There are 2 potential bugs left, tho:
- hitting a key should interrupt the completions processing (so that
  the long wait should not prevent you from getting work done).
  If it doesn't, then we have a bug.  Please report it separately, with
  as much details as possible to reproduce it (it's probably a problem
  in the C code).
- ideally completion should never take that long, so we probably have
  a performance bug somewhere.  Of course, that might also be in your
  local code (.emacs, icicles, ...).


-- Stefan