Sync code with tzcode2010m

asctime.c:
* Set errno to EINVAL and return "??? ??? ?? ??:??:?? ????\n" if
  asctime_r is called with a NULL struct tm pointer.  (Note that
  asctime_r is called by ctime_r and asctime; asctime is called by
  ctime.)

localtime.c:
* Set errno to EINVAL and return WRONG if time1 is called with a
  NULL struct tm pointer; avoid dereference if a NULL struct tm
  pointer is passed to timelocal, timegm, or timeoff.  (Note that
  time1 is called by mktime, timegm, and timeoff; mktime is called
  by timelocal.)
* more core-avoidance work
* Change to set timezone and altzone based on time types with
  greatest transition times (for the benefit of Asia/Seoul).

zic.8:
* Warning about case-sensitivity of names, but not of abbrevations

zic.c:
* Conditionally output extra types with most-recently-use offsets
  last (for use by systems with pre-2011 versions of localtime.c,
  helping to ensure that globals "altzone and "timezone" get set
  correctly).

The code has been running for nearly four weeks on my laptop running
FreeBSD 8.1 without a problem.

MFC after:	1 month

2 files changed, 52 insertions, 2 deletions

diff --git a/contrib/tzcode/zic/zic.8 b/contrib/tzcode/zic/zic.8
index fe09ef2..aa19131 100644
--- a/contrib/tzcode/zic/zic.8
+++ b/contrib/tzcode/zic/zic.8
@@ -119,6 +119,9 @@ Any line that is blank (after comment stripping) is ignored.
 Non-blank lines are expected to be of one of three types:
 rule lines, zone lines, and link lines.
 .Pp
+Names (such as month names) must be in English and are case insensitive.
+Abbreviations, if used, must be unambiguous in context.
+.Pp
 A rule line has the form:
 .Dl "Rule	NAME	FROM	TO	TYPE	IN	ON		AT	SAVE	LETTER/S"
 For example:
@@ -460,6 +463,6 @@ standard directory used for created files
 .Xr ctime 3 ,
 .Xr tzfile 5 ,
 .Xr zdump 8
-.\" @(#)zic.8	8.5
+.\" @(#)zic.8	8.6
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
diff --git a/contrib/tzcode/zic/zic.c b/contrib/tzcode/zic/zic.c
index 7670056..5fb8b53 100644
--- a/contrib/tzcode/zic/zic.c
+++ b/contrib/tzcode/zic/zic.c
@@ -3,7 +3,7 @@
 ** 2006-07-17 by Arthur David Olson.
 */
 
-static const char	elsieid[] = "@(#)zic.c	8.20";
+static const char	elsieid[] = "@(#)zic.c	8.22";
 
 #ifndef lint
 static const char rcsid[] =
@@ -1588,6 +1588,53 @@ const char * const	string;
 			if (thistimei == 0)
 				writetype[0] = TRUE;
 		}
+#ifndef LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH
+		/*
+		** For some pre-2011 systems: if the last-to-be-written
+		** standard (or daylight) type has an offset different from the
+		** most recently used offset,
+		** append an (unused) copy of the most recently used type
+		** (to help get global "altzone" and "timezone" variables
+		** set correctly).
+		*/
+		{
+			register int	mrudst, mrustd, hidst, histd, type;
+
+			hidst = histd = mrudst = mrustd = -1;
+			for (i = thistimei; i < thistimelim; ++i)
+				if (isdsts[types[i]])
+					mrudst = types[i];
+				else	mrustd = types[i];
+			for (i = 0; i < typecnt; ++i)
+				if (writetype[i]) {
+					if (isdsts[i])
+						hidst = i;
+					else	histd = i;
+				}
+			if (hidst >= 0 && mrudst >= 0 && hidst != mrudst &&
+				gmtoffs[hidst] != gmtoffs[mrudst]) {
+					isdsts[mrudst] = -1;
+					type = addtype(gmtoffs[mrudst],
+						&chars[abbrinds[mrudst]],
+						TRUE,
+						ttisstds[mrudst],
+						ttisgmts[mrudst]);
+					isdsts[mrudst] = TRUE;
+					writetype[type] = TRUE;
+			}
+			if (histd >= 0 && mrustd >= 0 && histd != mrustd &&
+				gmtoffs[histd] != gmtoffs[mrustd]) {
+					isdsts[mrustd] = -1;
+					type = addtype(gmtoffs[mrustd],
+						&chars[abbrinds[mrustd]],
+						FALSE,
+						ttisstds[mrustd],
+						ttisgmts[mrustd]);
+					isdsts[mrustd] = FALSE;
+					writetype[type] = TRUE;
+			}
+		}
+#endif /* !defined LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH */
 		thistypecnt = 0;
 		for (i = 0; i < typecnt; ++i)
 			typemap[i] = writetype[i] ?  thistypecnt++ : -1;