Re: highlight failed part of isearch input

["Robert J. Chassell" <bob@rattlesnake.com>]

    emacs -Q 
    In a buffer with text abcd, use `C-s abx RET'. Then use `C-s C-s
    DEL'. For me, it removes the entire search string.

isearch-delete-char (`DEL') removes the last entry, whether that be a
string of letters or a single letter.  The easiest way I know to get a
string of letters is with isearch-yank-word-or-char (`C-w'), but
typing them in works, too.

When I invoke isearch twice without isearch-yank-word-or-char, but put
in several characters each time, a single isearch-delete-char (`DEL')
removes the last character.  Then, when I get to the first part, it
removes all of it.

    ... I withdraw what I wrote. ...  

    If you use `C-s abx C-a' in a buffer with only `abcd', and then
    you use `C-s C-s C-M-w', the search string is changed from `abx'
    to `ab', but the prompt/echo still says "Failing", which is not
    really correct.

I think it is a bug.  The isearch-forward command correctly says
`Failing I-search' the first time it fails.  However, use of
isearch-del-char (`C-M-w') causes the isearch-forward command to light
up the other strings it can find (my test buffer is this message and
mentions `ise' several times as part of `isearch') and I can reach
them.  That is the bug.

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc