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From add02d6e5934100f023b45584d0227be90a297e8 Mon Sep 17 00:00:00 2001
From: Jan Synacek <jsynacek@redhat.com>
Date: Thu, 19 Oct 2017 09:53:56 +0200
Subject: [PATCH] timedatectl: stop using xstrftime
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When using strftime in arbitrary locales, we cannot really say how big the
buffer should be. Let's make the buffer "large", which will work fine pretty
much always, and just print n/a if the timestamp does not fit. strftime returns
0 if the buffer is too small and a NUL-terminated string otherwise, so we
can drop the size specifications in string formatting.

$ export LANG=fa_IR.UTF-8
$ date
چهارشنبه ۱۸ اكتبر ۱۷، ساعت ۱۰:۵۴:۲۴ (+0330)
$ timedatectl
Assertion 'xstrftime: a[] must be big enough' failed at ../src/timedate/timedatectl.c:105, function print_status_info(). Aborting.

now:

$ timedatectl
        Local time: چهارشنبه 2017-10-18 16:29:40 CEST
    Universal time: چهارشنبه 2017-10-18 14:29:40 UTC
          RTC time: چهارشنبه 2017-10-18 14:29:40
…

(cherry picked from commit 14ce0c25c28ba58e80084e28b4f23884199900e4)
Resolves: #1503942
---
 src/shared/time-util.h     |  2 --
 src/timedate/timedatectl.c | 49 ++++++++++++++++++++++++----------------------
 2 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/src/shared/time-util.h b/src/shared/time-util.h
index f2789142f..32e90902a 100644
--- a/src/shared/time-util.h
+++ b/src/shared/time-util.h
@@ -108,5 +108,3 @@ int get_timezones(char ***l);
 bool timezone_is_valid(const char *name);
 
 clockid_t clock_boottime_or_monotonic(void);
-
-#define xstrftime(buf, fmt, tm) assert_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0)
diff --git a/src/timedate/timedatectl.c b/src/timedate/timedatectl.c
index 1accccb68..3e9b657bc 100644
--- a/src/timedate/timedatectl.c
+++ b/src/timedate/timedatectl.c
@@ -93,8 +93,8 @@ static const char *jump_str(int delta_minutes, char *s, size_t size) {
 }
 
 static void print_status_info(const StatusInfo *i) {
-        char a[FORMAT_TIMESTAMP_MAX];
-        char b[FORMAT_TIMESTAMP_MAX];
+        char a[LINE_MAX];
+        char b[LINE_MAX];
         char s[32];
         struct tm tm;
         time_t sec;
@@ -104,6 +104,7 @@ static void print_status_info(const StatusInfo *i) {
         int dn = 0;
         bool is_dstc = false, is_dstn = false;
         int r;
+        size_t n;
 
         assert(i);
 
@@ -123,11 +124,11 @@ static void print_status_info(const StatusInfo *i) {
                 fprintf(stderr, "Warning: Could not get time from timedated and not operating locally.\n\n");
 
         if (have_time) {
-                xstrftime(a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&sec, &tm));
-                printf("      Local time: %.*s\n", (int) sizeof(a), a);
+                n = strftime(a, sizeof a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&sec, &tm));
+                printf("      Local time: %s\n", n > 0 ? a : "n/a");
 
-                xstrftime(a, "%a %Y-%m-%d %H:%M:%S UTC", gmtime_r(&sec, &tm));
-                printf("  Universal time: %.*s\n", (int) sizeof(a), a);
+                n = strftime(a, sizeof a, "%a %Y-%m-%d %H:%M:%S UTC", gmtime_r(&sec, &tm));
+                printf("  Universal time: %s\n", n > 0 ? a : "n/a");
         } else {
                 printf("      Local time: %s\n", "n/a");
                 printf("  Universal time: %s\n", "n/a");
@@ -137,24 +138,26 @@ static void print_status_info(const StatusInfo *i) {
                 time_t rtc_sec;
 
                 rtc_sec = (time_t)(i->rtc_time / USEC_PER_SEC);
-                xstrftime(a, "%a %Y-%m-%d %H:%M:%S", gmtime_r(&rtc_sec, &tm));
-                printf("        RTC time: %.*s\n", (int) sizeof(a), a);
+                n = strftime(a, sizeof a, "%a %Y-%m-%d %H:%M:%S", gmtime_r(&rtc_sec, &tm));
+                printf("        RTC time: %s\n", n > 0 ? a : "n/a");
         } else
                 printf("        RTC time: %s\n", "n/a");
 
         if (have_time)
-                xstrftime(a, "%Z, %z", localtime_r(&sec, &tm));
+                n = strftime(a, sizeof a, "%Z, %z", localtime_r(&sec, &tm));
 
-        printf("       Time zone: %s (%.*s)\n"
+        printf("       Time zone: %s (%s)\n"
                "     NTP enabled: %s\n"
                "NTP synchronized: %s\n"
                " RTC in local TZ: %s\n",
-               strna(i->timezone), (int) sizeof(a), have_time ? a : "n/a",
+               strna(i->timezone), have_time && n > 0 ? a : "n/a",
                i->ntp_capable ? yes_no(i->ntp_enabled) : "n/a",
                yes_no(i->ntp_synced),
                yes_no(i->rtc_local));
 
         if (have_time) {
+                size_t m;
+
                 r = time_get_dst(sec, "/etc/localtime",
                                  &tc, &zc, &is_dstc,
                                  &tn, &dn, &zn, &is_dstn);
@@ -164,26 +167,26 @@ static void print_status_info(const StatusInfo *i) {
                         printf("      DST active: %s\n", yes_no(is_dstc));
 
                         t = tc - 1;
-                        xstrftime(a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&t, &tm));
+                        n = strftime(a, sizeof a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&t, &tm));
 
-                        xstrftime(b, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&tc, &tm));
+                        m = strftime(b, sizeof b, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&tc, &tm));
                         printf(" Last DST change: DST %s at\n"
-                               "                  %.*s\n"
-                               "                  %.*s\n",
+                               "                  %s\n"
+                               "                  %s\n",
                                is_dstc ? "began" : "ended",
-                               (int) sizeof(a), a,
-                               (int) sizeof(b), b);
+                               n > 0 ? a : "n/a",
+                               m > 0 ? b : "n/a");
 
                         t = tn - 1;
-                        xstrftime(a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&t, &tm));
-                        xstrftime(b, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&tn, &tm));
+                        n = strftime(a, sizeof a, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&t, &tm));
+                        m = strftime(b, sizeof b, "%a %Y-%m-%d %H:%M:%S %Z", localtime_r(&tn, &tm));
                         printf(" Next DST change: DST %s (the clock jumps %s) at\n"
-                               "                  %.*s\n"
-                               "                  %.*s\n",
+                               "                  %s\n"
+                               "                  %s\n",
                                is_dstn ? "begins" : "ends",
                                jump_str(dn, s, sizeof(s)),
-                               (int) sizeof(a), a,
-                               (int) sizeof(b), b);
+                               n > 0 ? a : "n/a",
+                               m > 0 ? b : "n/a");
                 }
         } else
                 printf("      DST active: %s\n", yes_no(is_dstc));