Update.

1998-11-05  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/i386/fpu/bits/mathinline.h (__pow2): Fix fldl -> fld.

	* sysdeps/libm-i387/s_fma.S: Optimize a bit.
	* sysdeps/libm-i387/s_fmaf.S: Likewise.

1998-11-04 19:47 -0500  Zack Weinberg  <zack@rabi.phys.columbia.edu>

	* configure.in: Search for install-info and substitute it.
	Determine whether install-info is the buggy Debian version
	that doesn't understand INFO-DIR-SECTION.
	* config.make.in: Add INSTALL_INFO and OLD_DEBIAN_INSTALL_INFO
	to be substituted.
	* manual/Makefile: If OLD_DEBIAN_INSTALL_INFO, give
	install-info the --section argument it needs to work properly.
	(dir-add.texinfo): Delete target.
	(dir-add.info): Generate this directly.  Sort entries.  Put a
	colon at the end of the INFO-DIR-SECTION line.
	* manual/libc.texinfo: Put a colon at the end of the
	@dircategory line.

1998-11-05  Paul Eggert  <eggert@twinsun.com>

	* time/mktime.c (__mktime_internal): Adopt the traditional (and
	problematic) notion of what to do when tm_isdst doesn't match.

1998-11-04  Andreas Schwab  <schwab@issan.cs.uni-dortmund.de>

	* posix/PTESTS: Fix spelling.

1998-11-04  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* elf/dlopenold.c: Compile only if DO_VERSIONING is also defined.

1998-11-03  H.J. Lu  <hjl@gnu.org>

	* libio/fileops.c (new_do_write): New function.
	(_IO_new_do_write): Call new_do_write.
	(_IO_new_file_xsputn): Likewise.

	* libio/oldfileops.c (old_do_write): New function.
	(_IO_old_do_write): Call old_do_write.
	(_IO_old_file_xsputn): Likewise.

1 files changed, 23 insertions, 22 deletions

diff --git a/time/mktime.c b/time/mktime.c
index 2908db0784..673bb48266 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -350,31 +350,32 @@ __mktime_internal (tp, convert, offset)
 
   /* If we have a match, check whether tm.tm_isdst has the requested
      value, if any.  */
-  if (dt == 0 && 0 <= isdst && 0 <= tm.tm_isdst)
+  if (dt == 0 && isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst)
     {
-      int dst_diff = (isdst != 0) - (tm.tm_isdst != 0);
-      if (dst_diff)
+      /* tm.tm_isdst has the wrong value.  Look for a neighboring
+	 time with the right value, and use its UTC offset.
+	 Heuristic: probe the previous three calendar quarters (approximately),
+	 looking for the desired isdst.  This isn't perfect,
+	 but it's good enough in practice.  */
+      int quarter = 7889238; /* seconds per average 1/4 Gregorian year */
+      int i;
+
+      /* If we're too close to the time_t limit, look in future quarters.  */
+      if (t < TIME_T_MIN + 3 * quarter)
+	quarter = -quarter;
+
+      for (i = 1; i <= 3; i++)
 	{
-	  /* Move two hours in the direction indicated by the disagreement,
-	     probe some more, and switch to a new time if found.
-	     The largest known fallback due to daylight savings is two hours:
-	     once, in Newfoundland, 1988-10-30 02:00 -> 00:00.  */
-	  time_t ot = t - 2 * 60 * 60 * dst_diff;
-	  while (--remaining_probes != 0)
+	  time_t ot = t - i * quarter;
+	  struct tm otm;
+	  ranged_convert (convert, &ot, &otm);
+	  if (otm.tm_isdst == isdst)
 	    {
-	      struct tm otm;
-	      dt = ydhms_tm_diff (year, yday, hour, min, sec,
-				  ranged_convert (convert, &ot, &otm));
-	      if (dt == 0
-		  || (ot + dt == t
-		      && dst_diff == (isdst != 0) - (tm.tm_isdst != 0)))
-		{
-		  t = ot;
-		  tm = otm;
-		  break;
-		}
-	      if ((ot += dt) == t)
-		break;  /* Avoid a redundant probe.  */
+	      /* We found the desired tm_isdst.
+		 Extrapolate back to the desired time.  */
+	      t = ot + ydhms_tm_diff (year, yday, hour, min, sec, &otm);
+	      ranged_convert (convert, &t, &tm);
+	      break;
 	    }
 	}
     }