Subject: bug#27711: 25.2; org-feed gets old news as new from some feeds

From: Adonay Felipe Nogueira <[email-masked]>
Date: Fri, 14 Jul 2017 17:58:35 -0300

This was tested with `emacs -Q`.

1. In the Lisp Interaction buffer, evaluate:

--8<---------------cut here---------------start------------->8---
(require 'org-feed)
(setq org-feed-alist '(("Blog de Bradley Kuhn"
			"http://ebb.org/bkuhn/rss.xml"
			"~/Documentos/Notícias.org"
			"Blog de Bradley Kuhn")))
--8<---------------cut here---------------end--------------->8---

2. Then do M-x org-feed-update-all RET. Wait for the entries to be add
   to "~/Documentos/Notícias.org", inside "Blog de Bradley Kuhn".

3. Delete the entries inside "Blog de Bradley Kuhn", keep the FEEDSTATUS
   drawer.

4. Do (2) again.

Notice that the old news are fetched as if they were new. In other
feeds, this doesn't happen (that is: old news isn't fetched again).

My version of GNU Emacs comes from GNU Guix, which I'm using on top of
my copy of Trisquel. For viewing and trasparency purposes the GNU Guix
package recipe for GNU Emacs can be found in
[[https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/emacs.scm?id=v0.13.0-1333-g9383cee#n102]].

NOTE About weird paths seen from here on in this message: These are ways
with which GNU Guix uses to "store" any given package or version.

In GNU Emacs 25.2.1 (i686-pc-linux-gnu, GTK+ Version 3.22.15)
 of 2017-06-22 built on localhost
System Description:	Trisquel GNU/Linux 7.0, Belenos

Configured using:
 'configure
 CONFIG_SHELL=/gnu/store/hg46r8w06msw918nl2r6nx3qik5qfpmq-bash-4.4.12/bin/bash
 SHELL=/gnu/store/hg46r8w06msw918nl2r6nx3qik5qfpmq-bash-4.4.12/bin/bash
 --prefix=/gnu/store/c4i9jvj1p7amjzc5airfsjbidpg6fd71-emacs-25.2
 --enable-fast-install'

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND DBUS GSETTINGS NOTIFY ACL GNUTLS
LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_MONETARY: pt_BR.UTF-8
  value of $LC_NUMERIC: pt_BR.UTF-8
  value of $LC_TIME: pt_BR.UTF-8
  value of $LANG: pt_BR.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Org

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Clipboard pasted as level 2 subtree [261 times]
Position saved to mark ring, go back with C-c &.
Saving file /home/adfeno/Documentos/Notícias.org...
Wrote /home/adfeno/Documentos/Notícias.org
Added 261 new items from feed Blog de Bradley Kuhn to file Notícias.org, heading Blog de Bradley Kuhn
261 new entries from 1 feed
You can run the command ‘org-feed-update-all’ with C-c C-x g
261 new entries from 1 feed
Mark saved where search started
Mark set
funcall-interactively: End of buffer [2 times]

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rfc822 mml mml-sec epg
epg-config mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader
sendmail misearch multi-isearch pp parse-time org-capture xml
org-element org-rmail org-mhe org-irc org-info org-gnus org-docview
doc-view subr-x jka-compr image-mode dired org-bibtex bibtex org-bbdb
org-w3m mail-utils network-stream nsm starttls url-http tls gnutls
mail-parse rfc2231 rfc2047 rfc2045 ietf-drums url-gw url-cache url-auth
url url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util url-parse auth-source cl-seq eieio byte-opt bytecomp
byte-compile cl-extra cconv eieio-core cl-macs gv gnus-util mm-util
help-fns mail-prsvr password-cache url-vars mailcap org-feed org
org-macro org-footnote org-pcomplete pcomplete org-list org-faces
org-entities noutline outline easy-mmode org-version ob-emacs-lisp ob
ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys ob-comint comint
ansi-color ring ob-core ob-eval org-compat org-macs org-loaddefs
format-spec find-func cal-menu calendar cal-loaddefs help-mode easymenu
cl-loaddefs pcase cl-lib debug term/xterm xterm server time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel x-win term/common-win x-dnd tool-bar dnd fontset
image regexp-opt fringe tabulated-list newcomment elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cl-generic cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese charscript case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer cl-preloaded nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote dbusbind inotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 8 207748 47909)
 (symbols 24 28684 0)
 (miscs 20 186 678)
 (strings 16 46482 12738)
 (string-bytes 1 2888974)
 (vectors 8 27383)
 (vector-slots 4 1384845 49640)
 (floats 8 269 334)
 (intervals 28 5072 393)
 (buffers 520 22))

-- 
- [[https://libreplanet.org/wiki/User:Adfeno]]
- Palestrante e consultor sobre /software/ livre (não confundir com
  gratis).
- "WhatsApp"? Ele não é livre, por isso não uso. Iguais a ele prefiro
  GNU Ring, ou Tox. Quer outras formas de contato? Adicione o vCard
  que está no endereço acima aos teus contatos.
- Pretende me enviar arquivos .doc, .ppt, .cdr, ou .mp3? OK, eu
  aceito, mas não repasso. Entrego apenas em formatos favoráveis ao
  /software/ livre. Favor entrar em contato em caso de dúvida.