bug#4755: 23.1; case where `C-M-x' on defcustom doesn't seem to work

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tags 4755 unreproducible
quit

"Drew Adams" <drew.adams@oracle.com> writes:

> emacs -Q
>  
> (defcustom foo '(("foo" (f1 f2) f3) ("bar" (b1 b2) b3))
>   "..."
>   :type '(repeat
>    (cons
>     (choice :tag "a" string symbol)
>     (choice
>      (const :tag "b" nil)
>      (function :tag "c")
>      (list :tag "d"
>     (repeat (function :tag "e"))
>     (choice
>      (const :tag "f" nil)
>      (function :tag "g")))))))
>  
> (defcustom toto (copy-sequence foo)
>   "..."
>   :type '(repeat
>    (cons
>     (choice :tag "r" string symbol)
>     (choice
>      (const :tag "s" nil)
>      (function :tag "t")
>      (list :tag "u"
>     (repeat (function :tag "v"))
>     (choice
>      (const :tag "w" nil)
>      (function :tag "x")))))))
>  
> (defun f1 ())
> (defun f2 ())
> (defun f3 ())
>  
> (defun b1 ())
> (defun b2 ())
> (defun b3 ())
>  
> Then M-x customize-option foo
>  
> Insert another alist element, then set the value for the session, so
> foo's value now has 3 alist elements. Option toto's value is like
> foo's, but it is missing the first alist element (the new one).
>  
> Put point on toto's defcustom and do `C-M-x'. The value is not updated
> to be a copy of foo's current value. The value looks like it hasn't
> changed.
>  
> AFAIK, there are no side effects going on here. And if you explicitly
> do (setq toto (copy-sequence foo)), then it of course does get updated
> to reflect the latest foo value.
>  
> Seems like a bug. There's no doubt a simpler test case, but I have this
> ready-to-hand and don't feel like paring it down.
>  
>  
>  
> In GNU Emacs 23.1.1 (i386-mingw-nt5.1.2600)
>  of 2009-07-29 on SOFT-MJASON
> Windowing system distributor `Microsoft Corp.', version 5.1.2600
> configured using `configure --with-gcc (4.4)'
>  

Can't reproduce on Emacs 23.4, perhaps it was fixed?