bug#67161: 30.0.50; [PATCH] Add option `dired-filename-display-length'

[Drew Adams]

> 1. emacs -Q
> 2. type M-: (insert "visible " (propertize "hidden" 'invisible t))
> 3. C-s hidden

Just set or bind `isearch-filter-predicate' to
`isearch-range-invisible', to search only invisible text.

`C-h f isearch-range-invisible':

  isearch-range-invisible is a compiled Lisp function in ‘isearch.el’.

  (isearch-range-invisible BEG END)

  Return t if all the text from BEG to END is invisible.