I reconsidered this problem, and now I agree with you. I
was at first negative on signaling an error in
lisp_data_to_selection_data because I was not sure it is
safe to do that. But, I found that Fsignal is already use
in this function. So, I've just installed these changes.
2005-02-14 Kenichi Handa <address@hidden>
* coding.c (encode_coding_string): Always return a unibyte string.
If NOCOPY is nonzero and there's no need of encoding, make STR
unibyte directly.
* xselect.c (lisp_data_to_selection_data): If OBJ is a non-ASCII
multibyte string, signal an error instead of aborting.