[exim-cvs] Fix timestamp outputs for TAI timezone. Bug 2530

Commit:     158d713722a1635939f699a8ea1605e937866bfc
Parent:     c1cea16d93da8e47aa0d29e79d9b854cf2c50951
Author:     Arne Wörner <arne_woerner@???>
AuthorDate: Mon Feb 24 17:07:22 2020 +0000
Committer:  Jeremy Harris <jgh146exb@???>
CommitDate: Mon Feb 24 17:07:22 2020 +0000

    Fix timestamp outputs for TAI timezone.  Bug 2530
---
 doc/doc-txt/ChangeLog |  5 ++++
 src/src/tod.c         | 71 +++++++++++++++++++++++++++++----------------------
 2 files changed, 46 insertions(+), 30 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 116df90..8f583e2 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -131,6 +131,11 @@ JH/26 Fix use of the SIZE parameter on MAIL commands, on continued connections.
       only the first would provide a SIZE.  This was due to the size information
       not being properly tracked.

+JH/27 Bug 2530: When operating in a timezone with sub-minute offset, such as
+      TAI (at 37 seconds currently), pretend to be in UTC for time-related
+      expansion and logging.  Previously, spurious values such as a future
+      minute could be seen.
+

 Exim version 4.93
 -----------------
diff --git a/src/src/tod.c b/src/src/tod.c
index e7123f9..cdfd123 100644
--- a/src/src/tod.c
+++ b/src/src/tod.c
@@ -148,7 +148,8 @@ switch(type)
       {
       int diff_hour, diff_min;
       struct tm local;
-      memcpy(&local, t, sizeof(struct tm));
+      struct tm * lp = &local;
+      memcpy(lp, t, sizeof(struct tm));

       if (f.timestamps_utc)
     diff_hour = diff_min = 0;
@@ -156,13 +157,22 @@ switch(type)
     {
     struct tm * gmt = gmtime(&now.tv_sec);

-    diff_min = 60*(local.tm_hour - gmt->tm_hour) + local.tm_min - gmt->tm_min;
-    if (local.tm_year != gmt->tm_year)
-      diff_min += (local.tm_year > gmt->tm_year)? 1440 : -1440;
-    else if (local.tm_yday != gmt->tm_yday)
-      diff_min += (local.tm_yday > gmt->tm_yday)? 1440 : -1440;
-    diff_hour = diff_min/60;
-    diff_min  = abs(diff_min - diff_hour*60);
+    if (local.tm_sec == gmt->tm_sec)    /* usual case */
+      {
+      diff_min = 60 * (local.tm_hour - gmt->tm_hour)
+            + local.tm_min - gmt->tm_min;
+      if (local.tm_year != gmt->tm_year)
+        diff_min += (local.tm_year > gmt->tm_year) ? 1440 : -1440;
+      else if (local.tm_yday != gmt->tm_yday)
+        diff_min += (local.tm_yday > gmt->tm_yday) ? 1440 : -1440;
+      diff_hour = diff_min/60;
+      diff_min  = abs(diff_min - diff_hour*60);
+      }
+    else                    /* subminute offset, eg. TAI */
+      {
+      lp = gmt;                /* pretend we're in UTC */
+      diff_min = diff_hour = 0;
+      }
     }

       switch(type)
@@ -172,15 +182,15 @@ switch(type)
       if (LOGGING(millisec))
         (void) snprintf(CS timebuf, sizeof(timebuf),
           "%04u-%02u-%02u %02u:%02u:%02u.%03u %+03d%02d",
-          1900 + (uint)local.tm_year, 1 + (uint)local.tm_mon, (uint)local.tm_mday,
-          (uint)local.tm_hour, (uint)local.tm_min, (uint)local.tm_sec, (uint)(now.tv_usec/1000),
+          1900 + (uint)lp->tm_year, 1 + (uint)lp->tm_mon, (uint)lp->tm_mday,
+          (uint)lp->tm_hour, (uint)lp->tm_min, (uint)lp->tm_sec, (uint)(now.tv_usec/1000),
           diff_hour, diff_min);
       else
 #endif
         (void) snprintf(CS timebuf, sizeof(timebuf),
           "%04u-%02u-%02u %02u:%02u:%02u %+03d%02d",
-          1900 + (uint)local.tm_year, 1 + (uint)local.tm_mon, (uint)local.tm_mday,
-          (uint)local.tm_hour, (uint)local.tm_min, (uint)local.tm_sec,
+          1900 + (uint)lp->tm_year, 1 + (uint)lp->tm_mon, (uint)lp->tm_mday,
+          (uint)lp->tm_hour, (uint)lp->tm_min, (uint)lp->tm_sec,
           diff_hour, diff_min);
       break;

     /* tod_mbx: format used in MBX mailboxes - subtly different to tod_full */

-      #ifdef SUPPORT_MBX
+#ifdef SUPPORT_MBX
     case tod_mbx:
-        {
-        int len;
-        (void) snprintf(CS timebuf, sizeof(timebuf), "%02u-", (uint)local.tm_mday);
-        len = Ustrlen(timebuf);
-        len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b-%Y %H:%M:%S",
-          &local);
-        (void) snprintf(CS timebuf + len, sizeof(timebuf)-len, " %+03d%02d", diff_hour, diff_min);
-        }
+      {
+      int len = snprintf(CS timebuf, sizeof(timebuf),
+        "%02u-", (uint)lp->tm_mday);
+      len += Ustrftime(timebuf + len, sizeof(timebuf) - len,
+        "%b-%Y %H:%M:%S", lp);
+      (void) snprintf(CS timebuf + len, sizeof(timebuf)-len,
+        " %+03d%02d", diff_hour, diff_min);
+      }
       break;
-      #endif
+#endif

     /* tod_full: format used in Received: headers (use as default just in case
     called with a junk type value) */

     default:
-        {
-        int len = Ustrftime(timebuf, sizeof(timebuf), "%a, ", &local);
-        (void) snprintf(CS timebuf + len, sizeof(timebuf)-len, "%02u ", (uint)local.tm_mday);
-        len += Ustrlen(timebuf + len);
-        len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b %Y %H:%M:%S",
-          &local);
-        (void) snprintf(CS timebuf + len, sizeof(timebuf)-len, " %+03d%02d", diff_hour, diff_min);
-        }
+      {
+      int len = Ustrftime(timebuf, sizeof(timebuf), "%a, ", lp);
+      len += snprintf(CS timebuf + len, sizeof(timebuf)-len,
+        "%02u ", (uint)lp->tm_mday);
+      len += Ustrftime(timebuf + len, sizeof(timebuf) - len,
+        "%b %Y %H:%M:%S", lp);
+      (void) snprintf(CS timebuf + len, sizeof(timebuf)-len,
+        " %+03d%02d", diff_hour, diff_min);
+      }
       break;
     }
       }