Re: No coding system used for environment variables

[YAMAMOTO Mitsuharu]

>>>>> On Wed, 05 Mar 2008 11:25:59 -0500, Stefan Monnier 
>>>>> <monnier@iro.umontreal.ca> said:

>> But I'd strongly suggest to revert this changes at this timing of
>> pretest for upcoming Emacs 22.2.  First, some coding systems are
>> not ready until some .elc files get loaded (a chicken-and-egg
>> problem).  Second, as DECODE_FILE causes GC and string compaction
>> in general, some variables such as `nm' in Fexpand_file_name may
>> not point to valid data after that.  You may also want to see a
>> related patch in
>> http://lists.gnu.org/archive/html/emacs-pretest-bug/2007-05/msg00115.html

> How 'bout installing this change on the trunk?

While I was looking at the code of Fsubstitute_in_file_name to
make the patch for the trunk, I noticed that it contains a danger
of destination buffer shortage in both the EMACS_22_BASE branch
and the trunk.

*** src/fileio.c.~1.580.2.10.~  Thu Mar  6 09:44:27 2008
--- src/fileio.c        Fri Mar  7 20:55:26 2008
***************
*** 2227,2233 ****
        o = (unsigned char *) egetenv (target);
        if (o)
          {
!           total += strlen (o);
            substituted = 1;
          }
        else if (*p == '}')
--- 2227,2238 ----
        o = (unsigned char *) egetenv (target);
        if (o)
          {
!           if (STRING_MULTIBYTE (filename))
!             /* A unibyte character may occupy 2 bytes when converted
!                to multibyte.  */
!             total += strlen (o) * 2;
!           else
!             total += strlen (o);
            substituted = 1;
          }
        else if (*p == '}')

As I can't install it too soon, please install it to EMACS_22_BASE if
the next pretest is out shortly (and if the patch looks good, of
course.)

                                     YAMAMOTO Mitsuharu
                                mituharu@math.s.chiba-u.ac.jp