The attached patch against master fixes the issue on OS X 10.6 by
constraining frames to the visible area.  Behavior with OS X 10.9+ (and
"Spaces") still needs testing.  The patch also fixes
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=14713, which has
reappeared since it was fixed (at least it has reappeared on 10.6).

Also CCing Jan Djärv who worked on this area of the code previously (see
e61a31bf999b37f32616e5159196d179657ad788).