defvaralias

[Luc Teirlinck]

The old docstrings of define-obsolete-{function,variable}-alias
contained statements that if no docstring was provided, that is,
`(define-obsolete-{function,variable}-alias 'old 'new)', then OLD
would get the docstring of NEW, _unless_ it already had one.  This has
been replaced with references to the `defalias' and `defvaralias '
docs, which have no such "unless" statements.  The "unless" appears to
be definitely false in the `function' case.  But it is true in the
variable case.  That is because it is false for defalias, but true for
defvaralias.

There are two solutions for the variable case.  Document the fact in
the docstring and Elisp documentation of defvaralias, or make
defvaralias behave exactly like defalias and get rid of the "unless"
behavior.  I prefer the latter.  The patch below would implement
it.  I can install if desired.

To be more concrete:

After:

(defvar var1 "DOC1")
(defvar var2 "DOC2")
(defvaralias 'var1 'var2)

C-h v var1 RET

now shows "DOC1", whereas after the patch below it shows "DOC2", which
is behavior consistent with defalias.

===File ~/eval.c-diff=======================================
*** eval.c      03 May 2005 20:44:24 -0500      1.237
--- eval.c      05 May 2005 19:42:50 -0500      
***************
*** 747,752 ****
--- 747,754 ----
    LOADHIST_ATTACH (symbol);
    if (!NILP (docstring))
      Fput (symbol, Qvariable_documentation, docstring);
+   else
+     Fput (symbol, Qvariable_documentation, Qnil);
  
    return aliased;
  }
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