[PATCH] Fix mktime

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

The PR libc/2738 fix was not entirely correct, since even tm with tm_year 69
is representable in certain timezones. This caused e.g. perl-Date-Calc tests
to fail. Below is a fix. Years before 69 surely cannot be represented, for
69 it computes the year and checks for overflow afterwards.

2002-04-13  Jakub Jelinek  <jakub@redhat.com>

	* time/mktime.c (__mktime_internal): If year is 69, don't bail out
	early, but check whether it overflowed afterwards.
	* time/tst-mktime.c (main): Add new tests.

--- libc/time/mktime.c.jj	Sun Apr  7 17:52:27 2002
+++ libc/time/mktime.c	Sat Apr 13 11:12:05 2002
@@ -259,8 +259,10 @@ __mktime_internal (struct tm *tp,
 
   int sec_requested = sec;
 
-  /* Only years after 1970 are defined.  */
-  if (year < 70)
+  /* Only years after 1970 are defined.
+     If year is 69, it might still be representable due to
+     timezone differnces.  */
+  if (year < 69)
     return -1;
 
 #if LEAP_SECONDS_POSSIBLE
@@ -370,6 +372,14 @@ __mktime_internal (struct tm *tp,
 	return -1;
     }
 
+  if (year == 69)
+    {
+      /* If year was 69, need to check whether the time was representable
+	 or not.  */
+      if (t < 0 || t > 2 * 24 * 60 * 60)
+	return -1;
+    }
+
   *tp = tm;
   return t;
 }
--- libc/time/tst-mktime.c.jj	Sat Apr 13 11:45:06 2002
+++ libc/time/tst-mktime.c	Sat Apr 13 11:58:22 2002
@@ -5,7 +5,8 @@
 int
 main (void)
 {
-  struct tm time_str;
+  struct tm time_str, *tm;
+  time_t t;
   char daybuf[20];
   int result;
 
@@ -29,5 +30,38 @@ main (void)
       result = strcmp (daybuf, "Wednesday") != 0;
     }
 
+  setenv ("TZ", "EST", 1);
+#define EVENING69 1 * 60 * 60 + 2 * 60 + 29
+  t = EVENING69;
+  tm = localtime (&t);
+  if (tm == NULL)
+    {
+      (void) puts ("localtime returned NULL");
+      result = 1;
+    }
+  else
+    {
+      time_str = *tm;
+      t = mktime (&time_str);
+      if (t != EVENING69)
+        {
+          printf ("mktime returned %ld, expected %ld\n",
+		  (long) t, EVENING69);
+	  result = 1;
+        }
+      else
+        (void) puts ("Dec 31 1969 EST test passed");
+
+      setenv ("TZ", "CET", 1);
+      t = mktime (&time_str);
+      if (t != (time_t) -1)
+        {
+	  printf ("mktime returned %ld, expected -1\n", (long) t);
+	  result = 1;
+        }
+      else
+        (void) puts ("Dec 31 1969 CET test passed");
+    }
+
   return result;
 }

	Jakub