bug#19924: 24.4; incremental search for octal character

[Eli Zaretskii]

> Date: Fri, 6 Mar 2015 08:27:33 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 19924@debbugs.gnu.org, vose@eecs.utk.edu
> 
> > It means that we have a missing feature: we don't have any reasonable
> > way of typing unibyte characters at Isearch's prompt.  We need to
> > provide one.  There was such a kludgey feature in the past, but it
> > conflicted with a much more useful possibility of inserting Unicode
> > codepoints with C-q, and so the kludge was deleted in one of the
> > previous versions.  We need to restore it, at least for when Isearch
> > was initiated from a unibyte buffer.
> 
> Huh? AFAIK, since Emacs 24.4 you can use `C-x 8 RET' to append a
> Unicode char to the search string.

Raw bytes are not Unicode characters.  Try searching in the file the
OP attached to the original bug report, after you visit that file with
find-file-literally, and you will see the problem.  Emacs interprets
what you type after C-q or "C-x RET 8" as a Unicode codepoint, and
thus doesn't find raw bytes it has in unibyte buffers.

> If you have the Unicode character in the kill ring then you can
> also use `M-y'.  And you can also use `M-e' followed by `C-x 8 RET',
> of course.

All true, but not really relevant to the OP's problem.