bug#74198: 29.4; Newsticker reloads old items as new

[Eli Zaretskii <eliz@gnu.org>]

> From: BP25 <bp25@riseup.net>
> Date: Sun, 03 Nov 2024 21:56:09 +0000
> 
> In GNU Emacs 29.4 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.41,
> cairo version 1.18.0)
> System Description: Fedora Linux 39 (Workstation Edition)
> 
> PART A:
> 
> delete your newsticker folder
> emacs -nw -Q --load .emacs
> where .emacs contains:
> --8<---------------cut here---------------start------------->8---
> (custom-set-variables
>  '(newsticker-frontend 'newsticker-plainview)
>  '(newsticker-url-list
>    '(("Weather London" "https://weather-broker-cdn.api.bbci.co.uk/en/forecast/rss/3day/2643743" nil nil nil)))
>  '(newsticker-url-list-defaults nil)
>  '(newsticker-retrieval-interval 0)
>  '(newsticker-automatically-mark-items-as-old nil)
>    )
> --8<---------------cut here---------------end--------------->8---
> M-x newsticker-show-news
> M-x newsticker-get-all-news
> M-x newsticker-show-news
> Mark the items of the first (and only non-default) feed as old
> M-x newsticker-show-news
> 
> Expected result: the items previously visible as orange stay orange.
> Obtained result: the items previously visible as orange are white.
> 
> 
> PART B:
> 
> Same as PART A except remove the line
> '(newsticker-url-list-defaults nil)
> from .emacs
> 
> Expected result: the items previously visible as orange stay orange.
> Obtained result: the items previously visible as orange stay orange.
> 
> 
> PART C:
> 
> Same as PART A except remove the line
> '(newsticker-retrieval-interval 0)
> from .emacs
> 
> Expected result: the items previously visible as orange stay orange.
> Obtained result: the items previously visible as orange stay orange.
> 
> 
> ANALYSIS: There must be some conflict between
> '(newsticker-url-list-defaults nil) and '(newsticker-retrieval-interval 0)

The doc string of newsticker-retrieval-interval says

  If this value is not positive (i.e. less than or equal to 0)
  items are retrieved only once!

Doesn't that explain what you see?

(Disclaimer: I know nothing about newsticker.)