Add bug number.

diff --cc lisp/ChangeLog
index f4912f20545693a3d9fee6320ab18d8fffad3b4e,bc40df4c843bc329619512ace27c004de500ded2..d3b06645aa1b7399d8d8dda0b231e9d97799272c
--- 1/lisp/ChangeLog
--- 2/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@@ -6,7 -96,7 +96,7 @@@
  2010-01-15  Kenichi Handa  <handa@m17n.org>
  
        * international/mule-cmds.el (canonicalize-coding-system-name):
--      Convert "msXXX", "ibmXXX", "windows-XXX" to "cpXXX".
++      Convert "msXXX", "ibmXXX", "windows-XXX" to "cpXXX" (Bug#5387).
  
  2010-01-15  Glenn Morris  <rgm@gnu.org>