defvaralias

[Luc Teirlinck]

Output of C-h f defvaralias:

defvaralias is a built-in function.
(defvaralias SYMBOL ALIASED &optional DOCSTRING)

Make SYMBOL a variable alias for symbol ALIASED.  

Setting the value of SYMBOL will subsequently set the value of ALIASED, 
and getting the value of SYMBOL will return the value ALIASED has.
ALIASED nil means remove the alias; SYMBOL is unbound after that.
Third arg DOCSTRING, if non-nil, is documentation for SYMBOL.

My remarks:

This suggests that (defvaralias 'var nil) will make `var' cease to be
an alias if it was one and unbind var, if var was bound.  Instead, var
becomes, pretty logically, an alias for `nil'.  I looked at the code
in eval.c and the code makes not the slightest attempt to implement
any special behavior when ALIASED is `nil'.  I propose to just remove
the next to last line in the doc string and could commit this change
if desired.  I just want to make sure that the described behavior is
not _really_ intended (and hence the bug would be in the code rather
than in the doc string).

Sincerely,

Luc.