matz	2008-01-10 15:42:49 +0900 (Thu, 10 Jan 2008)

  New Revision: 14975

  Modified files:
    trunk/ChangeLog
    trunk/io.c

  Log:
    * io.c (io_encoding_set): handle nil for v1.

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/ChangeLog?r1=14975&r2=14974&diff_format=u
  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/io.c?r1=14975&r2=14974&diff_format=u