bug#12443: 24.2.50; Default values in the minibuffer prompt (fix inconsisntecy)

[Drew Adams]

> Has anybody written an Emacs-Lisp-aware grep?  That can list all
> hits of completing-read where the seventh parameter isn't nil?
> It doesn't sound that difficult to do, but I thought I'd ask
> before I start typing...

Yes.  See Michael Heerdegen's `el-search.el',
in GNU ELPA:

https://elpa.gnu.org/packages/el-search.html

Not a grep.  Better.