standards/56476: cd9660 unicode support simple hack

[Lee Chung-Yeol]

>Number:         56476
>Category:       standards
>Synopsis:       cd9660 unicode support simple hack
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-standards
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 04 21:40:16 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Lee Chung-Yeol <morning at chollian.net>
>Release:        FreeBSD 5.1-CURRENT i386
>Organization:
KAIST
>Environment:
System: FreeBSD nnci.kaist.ac.kr 5.1-CURRENT FreeBSD 5.1-CURRENT #2: Fri Aug 29 23:49:22 KST 2003 root at nnci.kaist.ac.kr:/usr/obj/usr/src/sys/MORNING i386


>Description:
	FreeBSD cd9660 module cannot handle the unicode. 
	Although there is a kernel module for other charset sysutils/cd9660_unicode,
	it can deal only the single byte charset.

	This patch is a fix for the cd9660_wchar2char() that is a hook function for translating unicode to char.
	
>How-To-Repeat:
	Just mount cd with multi-byte charset.
	
>Fix:
	Fix the isochar function in sys/isofs/cd9660/cd9660_util.c to return consumed number of bytes from the cd9660_wchar2char().
	Then, by hooking this, we can write ports similar to cd9660_unicode that offer the translation.

	Here is the diff file for cd9660_util.c and example cd9660_cp949 port.
	port is available at http://lovelyworm.sarang.net/ports/cd9660_cp949.tar.gz

*** cd9660_util.c.orig	Fri Sep  5 13:17:05 2003
--- cd9660_util.c	Fri Sep  5 13:18:12 2003
***************
*** 55,61 ****
   * Should be removed when native Unicode kernel
   * interfaces have been introduced.
   */
! u_char (*cd9660_wchar2char)(u_int32_t wchar) = NULL;
  
  /*
   * Get one character out of an iso filename
--- 55,61 ----
   * Should be removed when native Unicode kernel
   * interfaces have been introduced.
   */
! int (*cd9660_wchar2char)(u_int32_t wchar, u_char *c) = NULL;
  
  /*
   * Get one character out of an iso filename
***************
*** 85,91 ****
        }
        /* XXX: if Unicode conversion routine is loaded then use it */
        if (cd9660_wchar2char != NULL)
!             *c = cd9660_wchar2char((*(isofn - 1) << 8) | *isofn);
  
        return 2;
  }
--- 85,91 ----
        }
        /* XXX: if Unicode conversion routine is loaded then use it */
        if (cd9660_wchar2char != NULL)
!             return cd9660_wchar2char((*(isofn - 1) << 8) | *isofn, c);
  
        return 2;
  }

	


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