bug#2495: 23.0.91; regression in M-x flush-lines

[Juri Linkov <juri@jurta.org>]

>> emacs -Q
>> M-< ; beginning of *scratch* buffer
>> M-x flush-lines RET RET
>
> In 22.3, this used read-from-minibuffer, which returns the empty
> string in case of no input.
>
> Now it used read-regexp, which returns nil in case of no input (if no
> default is supplied). That doesn't seem right.
>
> Perhaps this:
>
> *** replace.el	9 Jan 2009 05:01:00 -0000	1.282
> --- replace.el	27 Feb 2009 21:41:59 -0000
> ***************
> *** 556,562 ****
>   	     (format "%s: " prompt))
>   	   nil nil nil 'regexp-history defaults t)))
>       (if (equal input "")
> ! 	default-value
>         (prog1 input
>   	(add-to-history 'regexp-history input)))))
>   
> --- 556,562 ----
>   	     (format "%s: " prompt))
>   	   nil nil nil 'regexp-history defaults t)))
>       (if (equal input "")
> ! 	(or default-value input)
>         (prog1 input
>   	(add-to-history 'regexp-history input)))))

Currently flush-lines always displays the misleading prompt

  Flush lines containing match for regexp (default ):
                                          ==========

where default is empty that makes no sense without a real
default value.

I think Glenn provided the correct patch for this bug (seen above).

-- 
Juri Linkov
http://www.jurta.org/emacs/