TAB expansion wrong on big5 chars containing "{"

[Dan Jacobson]

There is something wrong with your TAB expansion algorithm when there
is a { in the second byte of a big5 Chinese character.

You see, the filename we get from TAB expansion doesn't exist.
$ mkdir new; cd new
$ echo =B5{=B3q|qp-decode|xargs touch
$ ls <TAB> #expands the new file name, but the "{" sticks out
ls: ..{... No such file or directory
env is LC_CTYPE=zh_TW.Big5 LANG=zh_TW.Big5 LC_COLLATE=C LC_MESSAGES=C
$ echo *|xargs ls
is not affected.