Date: Sat, 18 Oct 1997 12:18:16 -0400 (EDT)
   From: "John F. Woods" <jfw@jfwhome.funhouse.com>

   Since when does mv require execute permission to move a file???
   (note: this is a cross-device "mv", so it's really a cp followed by
   rm, as was recently beaten to death by, uh, someone.  :-)

since it is cross-device mv, it copy from src to dst.  in other words,
read from src and write to dst.  to read from src, need to traverse
symlink.  to traverse, needs x bit...

isn't it?

enami.