Microsoft Windows XP [version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\armand.DOMAIN>svn --version
svn, version 1.5.0 (r31699)
   compiled Jun 23 2008, 12:59:48

Copyright (C) 2000-2008 CollabNet.
Subversion is open source software, see http://subversion.tigris.org/
This product includes software developed by CollabNet (http://www.Collab.Net/).

The following repository access (RA) modules are available:

* ra_neon : Module for accessing a repository via WebDAV protocol using Neon.
  - handles 'http' scheme
  - handles 'https' scheme
* ra_svn : Module for accessing a repository using the svn network protocol.
  - with Cyrus SASL authentication
  - handles 'svn' scheme
* ra_local : Module for accessing a repository on local disk.
  - handles 'file' scheme

C:\Documents and Settings\armand.DOMAIN>echo %LANG%
%LANG%

C:\Documents and Settings\armand.DOMAIN>echo %APR_ICONV_PATH%
%APR_ICONV_PATH%

C:\Documents and Settings\armand.DOMAIN>svnadmin create C:\diffaccent_svnrepo

C:\Documents and Settings\armand.DOMAIN>cd C:\

C:\>mkdir diffaccent_wc

C:\>cd diffaccent_wc

C:\diffaccent_wc>echo "hi" > file_with_accenté.txt

C:\diffaccent_wc>dir
 Le volume dans le lecteur C s'appelle Systeme
 Le numéro de série du volume est F447-5CC2

 Répertoire de C:\diffaccent_wc

29/07/2008  12:01    <REP>          .
29/07/2008  12:01    <REP>          ..
29/07/2008  12:01                 7 file_with_accenté.txt
               1 fichier(s)                7 octets
               2 Rép(s)     469 479 424 octets libres

C:\diffaccent_wc>svn import -m "import" file:///C:/diffaccent_svnrepo
Adding         file_with_accenté.txt

Committed revision 1.

C:\diffaccent_wc>del *
C:\diffaccent_wc\*, êtes-vous sûr (O/N) ? O

C:\diffaccent_wc>svn checkout file:///C:/diffaccent_svnrepo
Checked out revision 1.

C:\diffaccent_wc>dir
 Le volume dans le lecteur C s'appelle Systeme
 Le numéro de série du volume est F447-5CC2

 Répertoire de C:\diffaccent_wc

29/07/2008  12:05    <REP>          .
29/07/2008  12:05    <REP>          ..
29/07/2008  12:05    <REP>          diffaccent_svnrepo
               0 fichier(s)                0 octets
               3 Rép(s)     469 458 944 octets libres

C:\diffaccent_wc>cd diffaccent_svnrepo

C:\diffaccent_wc\diffaccent_svnrepo>echo "hello" > file_with_accenté.txt

C:\diffaccent_wc\diffaccent_svnrepo>svn -m "changes" commit
Sending        file_with_accenté.txt
Transmitting file data .
Committed revision 2.

C:\diffaccent_wc\diffaccent_svnrepo>svn diff -r1:2
Index: file_with_accenté.txt
===================================================================
--- file_with_accenté.txt       (revision 1)
+++ file_with_accenté.txt       (revision 2)
@@ -1 +1 @@
-"hi"
+"hello"

C:\diffaccent_wc\diffaccent_svnrepo>svn diff -r1:2 > mypatch.patch

C:\diffaccent_wc\diffaccent_svnrepo>type mypatch.patch
Index: file_with_accenté.txt
===================================================================
--- file_with_accenté.txt       (revision 1)
+++ file_with_accenté.txt       (revision 2)
@@ -1 +1 @@
-"hi"
+"hello"

REM Edited with an hexadecimal editor, the .patch contains 0x82 (, in Cp1252) instead of 0xE9 for the é of "file_with_accenté.txt"