From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 18 Sep 2017 03:38:12 +0000 (-0700)
Subject: Fix format-time-string %Z bug with negative tz
X-Git-Tag: emacs-26.0.90~142
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=541006c53623cb5fb7dfae475baae5d64fc6e9d0;p=emacs.git

Fix format-time-string %Z bug with negative tz

* src/editfns.c (tzlookup): Fix sign error in %Z when a purely
numeric zone is negative (Bug#28746).
* test/src/editfns-tests.el (format-time-string-with-zone):
Add test for this bug.
---

diff --git a/src/editfns.c b/src/editfns.c
index b03eb947dec..2f8b075817a 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -187,7 +187,8 @@ tzlookup (Lisp_Object zone, bool settz)
 		  if (sec != 0)
 		    prec += 2, numzone = 100 * numzone + sec;
 		}
-	      sprintf (tzbuf, tzbuf_format, prec, numzone,
+	      sprintf (tzbuf, tzbuf_format, prec,
+		       XINT (zone) < 0 ? -numzone : numzone,
 		       &"-"[XINT (zone) < 0], hour, min, sec);
 	      zone_string = tzbuf;
 	    }
diff --git a/test/src/editfns-tests.el b/test/src/editfns-tests.el
index 1c3fde888f6..f910afaf711 100644
--- a/test/src/editfns-tests.el
+++ b/test/src/editfns-tests.el
@@ -166,6 +166,10 @@
     (should (string-equal
              (format-time-string format look '(-28800 "PST"))
              "1972-06-30 15:59:59.999 -0800 (PST)"))
+    ;; Negative UTC offset, as a Lisp integer.
+    (should (string-equal
+             (format-time-string format look -28800)
+             "1972-06-30 15:59:59.999 -0800 (-08)"))
     ;; Positive UTC offset that is not an hour multiple, as a string.
     (should (string-equal
              (format-time-string format look "IST-5:30")