bug#43569: 28.0.50; Menu "Continue Tags Search" signals an error

[Juri Linkov <juri@linkov.net>]

This is a new bug report spun off from bug#43308.

>> Another problem is that selecting "Continue Tags Search"
>> signals the error:
>>
>> emacs -Q
>> Select "Edit" -> "Search" -> "Continue Tags Search"
>>
>> Lisp error: (wrong-type-argument commandp fileloop-continue)
>
> I don't see that with emacs -Q, loading menu-bar+.el,
> and using that item in the Search menu (which is not
> under Edit).  Dunno why.  I see just this error message:
> "No operation in progress", which makes sense.

The error occurs only when fileloop.el is not yet loaded.

>> I think "Continue Tags Search" should be disabled when it has no effect.
>
> I've done that now, in menu-bar+.el.  I use this, but
> perhaps someone can let me know if it's not the right,
> or best, condition to use.  (I use condition-case, not
> ignore-errors, for compatibility with older Emacs.)
>
> :enable (not (condition-case nil
>                  (tags-loop-eval tags-loop-scan)
>                (error t)))

I tried this, but it doesn't enable "Continue Tags Search"
after starting "Search Tagged Files...".  And I don't know
what else could be checked.