Re: copy-sequence no longer copies rings

[Richard Stallman]

    Hmm... In emulation/viper-cmd.el there are two such statements, but
    they were introduced by you on 2007-06-12. They were `copy-list'
    previously:

Aha, that explains it.  `copy-list' is a CL function, so it was
replaced with `copy-sequence', but `copy-sequence' doesn't handle
this case (which isn't a sequence).

Perhaps we should make `copy-sequence' copy dotted lists.  They are
not sequences, but that doesn't necessarily mean `copy-sequence' must
refuse to copy them.