commit 515a6f53cd984d5e6e374fbee52772f967fc3c73
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Mon Sep 13 22:49:45 2021 -0700
 
    Fix subscript error with odd TZif file [BZ #28338]
    
    * time/tzfile.c (__tzfile_compute): Fix unlikely off-by-one bug
    that accessed before start of an array when an oddball-but-valid
    TZif file was queried with an unusual time_t value.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
    (cherry picked from commit 645277434a42efc547d2cac8bfede4da10b4049f)
 
diff --git a/time/tzfile.c b/time/tzfile.c
index 4377018a55936389..190a777152b31cee 100644
--- a/time/tzfile.c
+++ b/time/tzfile.c
@@ -765,8 +765,7 @@ __tzfile_compute (__time64_t timer, int use_localtime,
   *leap_correct = leaps[i].change;
 
   if (timer == leaps[i].transition /* Exactly at the transition time.  */
-      && ((i == 0 && leaps[i].change > 0)
-	  || leaps[i].change > leaps[i - 1].change))
+      && (leaps[i].change > (i == 0 ? 0 : leaps[i - 1].change)))
     {
       *leap_hit = 1;
       while (i > 0