try-completion is inconsistent when completion-ignore-case=t

try-completion is inconsistent when completion-ignore-case=t

[Jonathan Yanver]

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In GNU Emacs 21.1.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2002-03-22 on ws-rh006.franklin.com
configured using `configure  --exec-prefix=/vol/emacs/pkgs/emacs21.1/i686 --prefix=/vol/emacs/pkgs/emacs21.1 --with-pop --with-xpm --with-jpeg --with-tiff --with-gif --with-png'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.iso885915
  locale-coding-system: iso-latin-9
  default-enable-multibyte-characters: nil

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:


(let ((x '(("TestOne") ("TestTwo")))
      (completion-ignore-case t))
  (print (try-completion "tes"  x))    ;A
  (print (try-completion "test" x))    ;B
  nil)

Results:
  A = "Test"
  B = "test"

I think that B should be "Test".

Same problem when x is an obarray.

Same problem in HEAD rev of Emacs CVS archive.

Re: try-completion is inconsistent when completion-ignore-case=t

[Richard Stallman]

I am not sure this is wrong.  When the string needs to be changed
for other reasons, Emacs adjusts the case.  When the string as given
is a match, Emacs returns it unchanged.

Re: try-completion is inconsistent when completion-ignore-case=t

[Jonathan Yavner]

RMS> When the string needs to be changed for other reasons, Emacs adjusts
RMS> the case.  When the string as given is a match, Emacs returns it
RMS> unchanged.

But "test" is not actually a match.  It's "Test" that's the match.  We're
fuzzing the difference via completion-ignore-case.  Suppose you're typing
in incremental text and the program is displaying the best match so far:

(1) t         => Test
(2) te        => Test
(3) tes       => Test
(4) test      => test
(5) testo     => TestOne
(6) teston    => TestOne
(7) testone   => TestOne

It looks weird to have the initial lowercase `t' only on line (4).