[BZ #473, BZ #487]

2004-10-27  Derek R. Price  <derek@ximbiot.com>
	[BZ #487] This change is imported from gnulib.
	* time/mktime.c (not_equal_tm) [DEBUG]: Remove redundant check.

2004-10-24  Paul Eggert  <eggert@cs.ucla.edu>

	[BZ #473]
	* time/tst-mktime.c (main): Don't assume that mktime fails
	when given time stamps before 1970.  It returns negative
	time_t values instead, for compatibility with BSD.

	* time/tst-mktime2.c: New file.
	* time/Makefile (tests): Add it.

	[BZ #473] Import from gnulib.  Revamp to avoid several problems near
	time_t extrema, and on hosts with 64-bit time_t and 32-bit int.
	This fixes Debian bug 177940.
	* time/mktime.c (TIME_T_MIDPOINT): New macro.
	(ydhms_diff): Renamed from ydhms_tm_diff, with a new signature,
	which avoids overflow problems on hosts with 64-bit time_t and
	32-bit int.  All callers changed.  Now an inline function.
	Verify at compile-time that long int is wide enough to avoid
	these overflow problems.
	(guess_time_tm): New function.
	(__mktime_internal): Use it.  Avoid overflow when computing yday on
	hosts with 64-bit long and 32-bit int.  Remove tests for 69;
	no longer needed.  Use if rather than #ifdef for LEAP_SECONDS_POSSIBLE
	so that the code is checked by more compilers.
	Do not rely on floating point to probe: stick to integer arithmetic,
	to avoid potential porting problems.
	Repair potential overflow correctly in the Southern Hemisphere.
	(localtime_offset): Add a FIXME for the case where time_t is unsigned.

1 files changed, 140 insertions, 0 deletions

diff --git a/time/tst-mktime2.c b/time/tst-mktime2.c
new file mode 100644
index 0000000000..fe7c370928
--- /dev/null
+++ b/time/tst-mktime2.c
@@ -0,0 +1,140 @@
+/* Test program from Paul Eggert and Tony Leneis.  */
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static time_t time_t_max;
+static time_t time_t_min;
+
+/* Values we'll use to set the TZ environment variable.  */
+static const char *tz_strings[] =
+  {
+    (const char *) 0, "GMT0", "JST-9",
+    "EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00"
+  };
+#define N_STRINGS ((int) (sizeof (tz_strings) / sizeof (tz_strings[0])))
+
+/* Fail if mktime fails to convert a date in the spring-forward gap.
+   Based on a problem report from Andreas Jaeger.  */
+static void
+spring_forward_gap (void)
+{
+  /* glibc (up to about 1998-10-07) failed this test. */
+  struct tm tm;
+
+  /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
+     instead of "TZ=America/Vancouver" in order to detect the bug even
+     on systems that don't support the Olson extension, or don't have the
+     full zoneinfo tables installed.  */
+  setenv ("TZ", "PST8PDT,M4.1.0,M10.5.0", 1);
+
+  tm.tm_year = 98;
+  tm.tm_mon = 3;
+  tm.tm_mday = 5;
+  tm.tm_hour = 2;
+  tm.tm_min = 0;
+  tm.tm_sec = 0;
+  tm.tm_isdst = -1;
+  if (mktime (&tm) == (time_t)-1)
+    exit (1);
+}
+
+static void
+mktime_test1 (time_t now)
+{
+  struct tm *lt = localtime (&now);
+  if (lt && mktime (lt) != now)
+    exit (2);
+}
+
+static void
+mktime_test (time_t now)
+{
+  mktime_test1 (now);
+  mktime_test1 ((time_t) (time_t_max - now));
+  mktime_test1 ((time_t) (time_t_min + now));
+}
+
+static void
+irix_6_4_bug (void)
+{
+  /* Based on code from Ariel Faigon.  */
+  struct tm tm;
+  tm.tm_year = 96;
+  tm.tm_mon = 3;
+  tm.tm_mday = 0;
+  tm.tm_hour = 0;
+  tm.tm_min = 0;
+  tm.tm_sec = 0;
+  tm.tm_isdst = -1;
+  mktime (&tm);
+  if (tm.tm_mon != 2 || tm.tm_mday != 31)
+    exit (3);
+}
+
+static void
+bigtime_test (int j)
+{
+  struct tm tm;
+  time_t now;
+  tm.tm_year = tm.tm_mon = tm.tm_mday = tm.tm_hour = tm.tm_min = tm.tm_sec = j;
+  now = mktime (&tm);
+  if (now != (time_t) -1)
+    {
+      struct tm *lt = localtime (&now);
+      if (! (lt
+	     && lt->tm_year == tm.tm_year
+	     && lt->tm_mon == tm.tm_mon
+	     && lt->tm_mday == tm.tm_mday
+	     && lt->tm_hour == tm.tm_hour
+	     && lt->tm_min == tm.tm_min
+	     && lt->tm_sec == tm.tm_sec
+	     && lt->tm_yday == tm.tm_yday
+	     && lt->tm_wday == tm.tm_wday
+	     && ((lt->tm_isdst < 0 ? -1 : 0 < lt->tm_isdst)
+		  == (tm.tm_isdst < 0 ? -1 : 0 < tm.tm_isdst))))
+	exit (4);
+    }
+}
+
+static int
+do_test (void)
+{
+  time_t t, delta;
+  int i, j;
+
+  setenv ("TZ", "America/Sao_Paulo", 1);
+  /* This test makes some buggy mktime implementations loop.
+     Give up after 60 seconds; a mktime slower than that
+     isn't worth using anyway.  */
+  alarm (60);
+
+  for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2)
+    continue;
+  time_t_max--;
+  if ((time_t) -1 < 0)
+    for (time_t_min = -1; (time_t) (time_t_min * 2) < 0; time_t_min *= 2)
+      continue;
+  delta = time_t_max / 997; /* a suitable prime number */
+  for (i = 0; i < N_STRINGS; i++)
+    {
+      if (tz_strings[i])
+	setenv ("TZ", tz_strings[i], 1);
+
+      for (t = 0; t <= time_t_max - delta; t += delta)
+	mktime_test (t);
+      mktime_test ((time_t) 1);
+      mktime_test ((time_t) (60 * 60));
+      mktime_test ((time_t) (60 * 60 * 24));
+
+      for (j = 1; 0 < j; j *= 2)
+	bigtime_test (j);
+      bigtime_test (j - 1);
+    }
+  irix_6_4_bug ();
+  spring_forward_gap ();
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"