bug#3229: 23.0.93; ediff-directories isn't buffer coding system independent

bug#3229: 23.0.93; ediff-directories isn't buffer coding system independent

[Robert Marshall]

I have two files with the same name (extracted from two svn
repositories) one of which has a coding system of undecided-dos, the
other is undecided-unix.

WHen I perform an ediff-buffers between the two files loaded into
emacs I get - correctly - zero reported differences. However if I look
at the differences using ediff-directories I get a single difference
region consisting of the whole file.

If I manually set the coding systems in the two files to be identical
then ediff-directories works correctly reporting no differences.


In GNU Emacs 23.0.93.1 (i686-pc-linux-gnu, GTK+ Version 2.14.4)
 of 2009-05-05 on robert-laptop
Windowing system distributor `The X.Org Foundation', version 11.0.10502000
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_GB.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: F90

Minor modes in effect:
  desktop-save-mode: t
  recentf-mode: t
  show-paren-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:

Recent messages:
Processing difference regions ... done
Region 1 exceeds the auto-refinement limit. Type `*' to refine [2 times]
Quit this Ediff session & show containing session group? (y or n) 
Quit this session group? (y or n) 
Making completion list... [2 times]
Computing differences between iec909MatrixOps.f90 and iec909MatrixOps.f906806DzI ...
Processing difference regions ... done
Quit this Ediff session? (y or n) 
Making completion list... [2 times]
Type C-x 4 C-o RET to restore the other window, C-M-v to scroll help.

bug#3229: 23.0.93; ediff-directories isn't buffer coding system independent

[Stefan Monnier]

> I have two files with the same name (extracted from two svn
> repositories) one of which has a coding system of undecided-dos, the
> other is undecided-unix.

> WHen I perform an ediff-buffers between the two files loaded into
> emacs I get - correctly - zero reported differences. However if I look
> at the differences using ediff-directories I get a single difference
> region consisting of the whole file.

Presumably you'll get the same "one big hunk diff" if you use
ediff-files.  Both ediff-files and ediff-directories work (as the name
implies) on files (and directories), not on buffers.  While the two
buffers show similar (or even identical) contents, the corresponding
files are different (contain different byte sequences because of the
different coding-system).


        Stefan

bug#3229: 23.0.93; ediff-directories isn't buffer coding system independent

[Drew Adams]

> > I have two files with the same name (extracted from two svn
> > repositories) one of which has a coding system of undecided-dos, the
> > other is undecided-unix.
> 
> > WHen I perform an ediff-buffers between the two files loaded into
> > emacs I get - correctly - zero reported differences. 
> > However if I look at the differences using ediff-directories I
> > get a single difference region consisting of the whole file.
> 
> Presumably you'll get the same "one big hunk diff" if you use
> ediff-files.  Both ediff-files and ediff-directories work (as the name
> implies) on files (and directories), not on buffers.  While the two
> buffers show similar (or even identical) contents, the corresponding
> files are different (contain different byte sequences because of the
> different coding-system).

Caveat: I haven't followed this thread, but this sounds similar to bug #1183.

I believe that the #1183 thread ended with Eli asking Michael Kifer to have
Ediff let you know that the two have the same (or similar) content but different
coding systems and hence different byte sequences.

Perhaps that never got fixed/finished?

bug#3229: 23.0.93; ediff-directories isn't buffer coding system independent

[Andrew Hyatt]

"Drew Adams" <drew.adams@oracle.com> writes:

>> > I have two files with the same name (extracted from two svn
>> > repositories) one of which has a coding system of undecided-dos, the
>> > other is undecided-unix.
>> 
>> > WHen I perform an ediff-buffers between the two files loaded into
>> > emacs I get - correctly - zero reported differences. 
>> > However if I look at the differences using ediff-directories I
>> > get a single difference region consisting of the whole file.
>> 
>> Presumably you'll get the same "one big hunk diff" if you use
>> ediff-files.  Both ediff-files and ediff-directories work (as the name
>> implies) on files (and directories), not on buffers.  While the two
>> buffers show similar (or even identical) contents, the corresponding
>> files are different (contain different byte sequences because of the
>> different coding-system).
>
> Caveat: I haven't followed this thread, but this sounds similar to bug #1183.
>
> I believe that the #1183 thread ended with Eli asking Michael Kifer to have
> Ediff let you know that the two have the same (or similar) content but different
> coding systems and hence different byte sequences.
>
> Perhaps that never got fixed/finished?

It sounds to me that this is more of a feature request than a bug at
this point. If anyone disagrees, let me know, otherwise I'll reclassify
this in a few weeks.