http.c: Use expected timezone abbreviation

The struct tm instance consumed by append_expire is provided by users
and could refer to any timezone, rather than GMT only.

According to Wikipedia [1], timezone abbreviations are either 3 or 4
characters long, or use numeric UTC offsets.

[1]: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#Time_zone_abbreviations

1 files changed, 2 insertions, 2 deletions

diff --git a/http.c b/http.c
index 978eea6..d87a5e5 100644
--- a/http.c
+++ b/http.c
@@ -2753,7 +2753,7 @@ failure:
 static int append_expire(struct dynstr *const d, const struct tm *const exp)
 {
     int ret = -1;
-    char s[sizeof "Thu, 01 Jan 1970 00:00:00 GMT"];
+    char s[sizeof "Thu, 01 Jan 1970 00:00:00 XXXX"];
     const locale_t l = newlocale(LC_TIME_MASK, "POSIX", (locale_t)0);
 
     if (l == (locale_t)0)
@@ -2761,7 +2761,7 @@ static int append_expire(struct dynstr *const d, const struct tm *const exp)
         fprintf(stderr, "%s: newlocale(3): %s\n", __func__, strerror(errno));
         goto end;
     }
-    else if (!strftime_l(s, sizeof s, "%a, %d %b %Y %H:%M:%S GMT", exp, l))
+    else if (!strftime_l(s, sizeof s, "%a, %d %b %Y %H:%M:%S %Z", exp, l))
     {
         fprintf(stderr, "%s: strftime_l(3) failed\n", __func__);
         return -1;