Sorry for the late response.

In article <87tzfhadwr.fsf@escher.local.home>, Stephen Berman <stephen.berman@gmx.net> writes:

> This fix results in a file mode specification error.  To reproduce:
> 1. C-x C-f /tmp/test
> 2. Type the letter "$(D+#(B" (a-umlaut).
> 3. C-x C-s
> 4. C-x k RET
> 5. C-x C-f /tmp/test
> ==> File mode specification error: (error "Can't convert the 0th
> character to unibyte")

It seems that this bug is already fixed by Juanma (thanks).

2008-06-27  Juanma Barranquero  <lekktu@gmail.com>

	* image.el (image-jpeg-p): Don't fail if the arg cannot be converted
	to unibyte; just assume it is not a JPEG.  Use `string-match-p'.
	(image-type-from-data, image-type-from-file-name): Use `string-match-p'.
	(image-type-from-buffer): Use `looking-at-p'.

---
Kenichi Handa
handa@ni.aist.go.jp