bug#26328: 26.0.50; checkdoc action for join lines drops final "

[Noam Postavsky <npostavs@gmail.com>]

>> Suggestion for a fix:
>>
>> modified   lisp/emacs-lisp/checkdoc.el
>> @@ -1520,7 +1520,7 @@ checkdoc-this-string-valid-engine
>>  			 ;; They said yes.  We have more fill work to do...
>>  			 (goto-char (match-beginning 1))
>>  			 (delete-region (point) (match-end 1))
>> -			 (insert "\n")
>> +			 (insert "\"")
>>  			 (setq msg nil))))))
>>  	   (if msg
>>  	       (checkdoc-create-error msg s (save-excursion
>
> The " at the end of the doc string is removed by that `delete-region',
> so it's all a bit confusing.  The following patch also fixes the problem
> in this example, but I'm not quite sure what the code is attempting to
> do here.
>
> Anybody familiar with this code?
>
> diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
> index 830743f5f8..7ac557711a 100644
> --- a/lisp/emacs-lisp/checkdoc.el
> +++ b/lisp/emacs-lisp/checkdoc.el
> @@ -1498,12 +1498,7 @@ checkdoc-this-string-valid-engine
>  			p (1+ p)
>  			"1st line not a complete sentence.  Join these lines? "
>  			" " t)
> -		       (progn
> -			 ;; They said yes.  We have more fill work to do...
> -			 (goto-char (match-beginning 1))
> -			 (delete-region (point) (match-end 1))
> -			 (insert "\n")
> -			 (setq msg nil))))))
> +		       (setq msg nil)))))
>  	   (if msg
>  	       (checkdoc-create-error msg s (save-excursion
>  					      (goto-char s)

AFAICT, both proposed patches will do the wrong thing for this case:

    (defun foo ()
      "Bla bla
    bla bla.  More words
    bla bla bla.")