emacs thinks UTF-8 can't encode Japanese text?

[James Ralston <ralston@pobox.com>]

I posted the following to gnu.emacs.help:

On 2005-01-12 at 01:32-05, James Ralston wrote:

> I'm trying to use Emacs 21.3 on Fedora Core 3 to edit files
> containing Japanese text encoded with UTF-8.
> 
> I've used the same version of Emacs on Fedora Core 2 with no
> problems.  Everything just works.  My locale is the same on both
> systems: en_US.UTF-8.
> 
> But on my FC3 system, if I visit a UTF-8 encoded file, the Japanese
> characters display as empty boxes.  Also, if I paste Japanese text
> into an Emacs window, and try to save the buffer, I receive this
> message:
> 
>> These default coding systems were tried:
>>   utf-8-unix
>> However, none of them safely encodes the target text.
> 
> This message makes no sense, because UTF-8 encodes everything.
> 
> On my FC2 system, here's what "C-u C-x =" says:
> 
>>   character: い (0151044, 53796, 0xd224)
>>     charset: japanese-jisx0208 (JISX0208.1983/1990 Japanese Kanji: ISO-IR-87)
>>  code point: 36 36
>>      syntax: word
>>    category: H:Japanese Hiragana characters of 2-byte character sets  
>>              j:Japanese  
>>              |:While filling, we can break a line at this character.  
>> buffer code: 0x92 0xA4 0xA4
>>   file code: 0xE3 0x81 0x84 (encoded by coding system utf-8-unix)
>>        font: -mplus-gothic-medium-R-normal--12-120-75-75-C-120-jisx0208.1990-0
> 
> On my FC3 system, here's what "C-u C-x =" on the same character says:
> 
>>   character: い (0151044, 53796, 0xd224)
>>     charset: japanese-jisx0208 (JISX0208.1983/1990 Japanese Kanji: ISO-IR-87)
>>  code point: 36 36
>>      syntax: word
>>    category: H:Japanese Hiragana characters of 2-byte character sets  
>>              j:Japanese  
>>              |:While filling, we can break a line at this character.  
>> buffer code: 0x92 0xA4 0xA4
>>   file code: not encodable by coding system utf-8-unix
>>        font: -mplus-gothic-medium-R-normal--12-120-75-75-C-120-jisx0208.1990-0
> 
> The only difference is the "file code:" line.  But I don't
> understand why Emacs 21.3 on FC3 doesn't think that UTF-8 encodes
> that character, because it absolutely does.
> 
> The FC3 packager claims that he has no problems:
> 
> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=144707
> 
> Does anyone have any ideas?

The more I ponder this, the more I'm beginning to think that this is
actually a bug with Emacs that I've managed to trigger somehow.
Claiming that UTF-8 doesn't encode い is bogus.

I've even gone so far as to trace Emacs while I open a file that
contains Japanese characters, but I didn't detect any glaring
differences between Emacs on FC2 (which works) and Emacs on FC3 (which
doesn't work).

I'm just about out of ideas.  Does anyone else have any?

Thanks,
James