master 8c13e84978 1/7: Fix newsticker timezone decode

[Paul Eggert]

branch: master
commit 8c13e8497821881b5197a1717e9e53b9991859d0
Author: LdBeth <andpuke@foxmail.com>
Commit: Paul Eggert <eggert@cs.ucla.edu>

    Fix newsticker timezone decode
    
    'newsticker--decode-rfc822-date' has the regex pattern for
    North American timezones but the actual timezone conversion
    for them was not implmented. Now cond cases are added to
    handle them as specified in RFC822.
    
    Copyright-paperwork-exempt: yes
---
 lisp/net/newst-backend.el | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/lisp/net/newst-backend.el b/lisp/net/newst-backend.el
index af196ccecf..2a87742fdf 100644
--- a/lisp/net/newst-backend.el
+++ b/lisp/net/newst-backend.el
@@ -1623,7 +1623,7 @@ Sat, 07 Sep 2002 00:00:01 GMT
               ":\\([0-9]\\{2\\}\\)"
               ;; second
               "\\(:\\([0-9]\\{2\\}\\)\\)?"
-              ;; zone -- fixme
+              ;; zone
               "\\(\\s-+\\("
               "UT\\|GMT\\|EST\\|EDT\\|CST\\|CDT\\|MST\\|MDT\\|PST\\|PDT"
               "\\|\\([-+]\\)\\([0-9]\\{2\\}\\)\\([0-9]\\{2\\}\\)"
@@ -1642,16 +1642,26 @@ Sat, 07 Sep 2002 00:00:01 GMT
               (offset-hour (read (or (match-string 14 rfc822-string)
                                      "0")))
               (offset-minute (read (or (match-string 15 rfc822-string)
-                                       "0")))
-              ;;FIXME
-              )
+                                       "0"))))
           (when zone
             (cond ((string= sign "+")
                    (setq hour (- hour offset-hour))
                    (setq minute (- minute offset-minute)))
                   ((string= sign "-")
                    (setq hour (+ hour offset-hour))
-                   (setq minute (+ minute offset-minute)))))
+                   (setq minute (+ minute offset-minute)))
+                  ((or (string= zone "UT") (string= zone "GMT"))
+                   nil)
+                  ((string= zone "EDT")
+                   (setq hour (+ hour 4)))
+                  ((or (string= zone "EST") (string= zone "CDT"))
+                   (setq hour (+ hour 5)))
+                  ((or (string= zone "CST") (string= zone "MDT"))
+                   (setq hour (+ hour 6)))
+                  ((or (string= zone "MST") (string= zone "PDT"))
+                   (setq hour (+ hour 7)))
+                  ((string= zone "PST")
+                   (setq hour (+ hour 8)))))
           (condition-case error-data
               (let ((i 1))
                 (dolist (m '("Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug"