tzdata 2022a

contrib/tzdata/CONTRIBUTING

@@ -1,50 +1,58 @@
-Contributing to the tz code and data
+# Contributing to the tz code and data
+
+Please do not create issues or pull requests on GitHub, as the
+proper procedure for proposing and distributing patches is via
+email as described below.
 
 The time zone database is by no means authoritative: governments
 change timekeeping rules erratically and sometimes with little
 warning, the data entries do not cover all of civil time before
 1970, and undoubtedly errors remain in the code and data.  Feel
 free to fill gaps or fix mistakes, and please email improvements
-to [email protected] for use in the future.  In your email, please give
+to <[email protected]> for use in the future.  In your email, please give
 reliable sources that reviewers can check.
 
------
-
-Developers can contribute technical changes to the source code and
-data as follows.
+## Contributing technical changes
 
 To email small changes, please run a POSIX shell command like
 'diff -u old/europe new/europe >myfix.patch', and attach
-myfix.patch to the email.
+'myfix.patch' to the email.
 
 For more-elaborate or possibly-controversial changes,
 such as renaming, adding or removing zones, please read
-<https://www.iana.org/time-zones/repository/theory.html> or the file
-theory.html.  It is also good to browse the mailing list archives
+"Theory and pragmatics of the tz code and data"
+<https://www.iana.org/time-zones/repository/theory.html>.
+It is also good to browse the mailing list archives
 <https://mm.icann.org/pipermail/tz/> for examples of patches that tend
 to work well.  Additions to data should contain commentary citing
-reliable sources as justification.  Citations should use https: URLs
+reliable sources as justification.  Citations should use "https:" URLs
 if available.
 
-Please submit changes against either the latest release in
-<https://www.iana.org/time-zones> or the master branch of the development
-repository.  The latter is preferred.  If you use Git the following
-workflow may be helpful:
+For changes that fix sensitive security-related bugs, please see the
+distribution's 'SECURITY' file.
+
+Please submit changes against either the latest release
+<https://www.iana.org/time-zones> or the main branch of the development
+repository.  The latter is preferred.
+
+## Sample Git workflow for developing contributions
+
+If you use Git the following workflow may be helpful:
 
   * Copy the development repository.
 
-      git clone https://github.com/eggert/tz.git
-      cd tz
+        git clone https://github.com/eggert/tz.git
+        cd tz
 
-  * Get current with the master branch.
+  * Get current with the main branch.
 
-      git checkout master
-      git pull
+        git checkout main
+        git pull
 
   * Switch to a new branch for the changes.  Choose a different
     branch name for each change set.
 
-      git checkout -b mybranch
+        git checkout -b mybranch
 
   * Sleuth by using 'git blame'.  For example, when fixing data for
     Africa/Sao_Tome, if the command 'git blame africa' outputs a line
@@ -57,36 +65,33 @@ workflow may be helpful:
 
   * Debug the changes, e.g.:
 
-      make check
-      make install
-      ./zdump -v America/Los_Angeles
+        make check
+        make install
+        ./zdump -v America/Los_Angeles
 
   * For each separable change, commit it in the new branch, e.g.:
 
-      git add northamerica
-      git commit
+        git add northamerica
+        git commit
 
     See recent 'git log' output for the commit-message style.
 
-  * Create patch files 0001-*, 0002-*, ...
+  * Create patch files 0001-..., 0002-..., ...
 
-      git format-patch master
+        git format-patch main
 
-  * After reviewing the patch files, send the patches to [email protected]
+  * After reviewing the patch files, send the patches to <[email protected]>
     for others to review.
 
-      git send-email master
+        git send-email main
 
     For an archived example of such an email, see
+    "[PROPOSED] Fix off-by-1 error for Jamaica and T&C before 1913"
     <https://mm.icann.org/pipermail/tz/2018-February/026122.html>.
 
-  * Start anew by getting current with the master branch again
+  * Start anew by getting current with the main branch again
     (the second step above).
 
-Please do not create issues or pull requests on GitHub, as the
-proper procedure for proposing and distributing patches is via
-email as illustrated above.
-
 -----
 
 This file is in the public domain.

contrib/tzdata/Makefile

@@ -45,9 +45,9 @@ LOCALTIME=	GMT
 #
 # Any other value for POSIXRULES is obsolete and should not be relied on, as:
 # * It does not work correctly in popular implementations such as GNU/Linux.
-# * It does not work in the tzdb implementation for timestamps after 2037.
-# * It is incompatible with 'zic -b slim' if POSIXRULES specifies transitions
-#   at standard time or UT rather than at local time.
+# * It does not work even in tzcode, except for historical timestamps
+#   that precede the last explicit transition in the POSIXRULES file.
+#   Hence it typically does not work for current and future timestamps.
 # In short, software should avoid ruleless settings like TZ='EET-2EEST'
 # and so should not depend on the value of POSIXRULES.
 #
@@ -122,8 +122,8 @@ LIBDIR = $(TOPDIR)/$(USRDIR)/lib
 
 # Types to try, as an alternative to time_t.
 TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL)
-TIME_T_ALTERNATIVES_HEAD = int64_t
-TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t
+TIME_T_ALTERNATIVES_HEAD = int_least64_t
+TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t
 
 # What kind of TZif data files to generate.  (TZif is the binary time
 # zone data format that zic generates; see Internet RFC 8536.)
@@ -152,8 +152,10 @@ REDO=		posix_right
 # The EXPIRES_LINE value matters only if REDO's value contains "right".
 # If you change EXPIRES_LINE, remove the leapseconds file before running "make".
 # zic's support for the Expires line was introduced in tzdb 2020a,
-# and EXPIRES_LINE defaults to 0 for now so that the leapseconds file
-# can be given to older zic implementations.
+# and was modified in tzdb 2021b to generate version 4 TZif files.
+# EXPIRES_LINE defaults to 0 for now so that the leapseconds file
+# can be given to pre-2020a zic implementations and so that TZif files
+# built by newer zic implementations can be read by pre-2021b libraries.
 EXPIRES_LINE=	0
 
 # To install data in text form that has all the information of the TZif data,
@@ -210,6 +212,7 @@ LDLIBS=
 #  -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function
 #  -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
 #	localtime_rz can make zdump significantly faster, but is nonstandard.
+#  -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure.
 #  -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
 #	functions like 'link' or variables like 'tzname' required by POSIX
 #  -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
@@ -220,7 +223,6 @@ LDLIBS=
 #  -DHAVE_STRTOLL=0 if your system lacks the strtoll function
 #  -DHAVE_SYMLINK=0 if your system lacks the symlink function
 #  -DHAVE_SYS_STAT_H=0 if your compiler lacks a <sys/stat.h>
-#  -DHAVE_SYS_WAIT_H=0 if your compiler lacks a <sys/wait.h>
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
 #  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>
 #  -Dlocale_t=XXX if your system uses XXX instead of locale_t
@@ -257,22 +259,26 @@ LDLIBS=
 GCC_INSTRUMENT = \
   -fsanitize=undefined -fsanitize-address-use-after-scope \
   -fsanitize-undefined-trap-on-error -fstack-protector
+# Omit -fanalyzer from GCC_DEBUG_FLAGS, as it makes GCC too slow.
 GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
   $(GCC_INSTRUMENT) \
   -Wall -Wextra \
   -Walloc-size-larger-than=100000 -Warray-bounds=2 \
   -Wbad-function-cast -Wcast-align=strict -Wdate-time \
   -Wdeclaration-after-statement -Wdouble-promotion \
+  -Wduplicated-branches -Wduplicated-cond \
   -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
-  -Winit-self -Wjump-misses-init -Wlogical-op \
+  -Winit-self -Wlogical-op \
   -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
+  -Wnull-dereference \
   -Wold-style-definition -Woverlength-strings -Wpointer-arith \
-  -Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=4 \
+  -Wshadow -Wshift-overflow=2 -Wstrict-overflow \
+  -Wstrict-prototypes -Wstringop-overflow=4 \
   -Wstringop-truncation -Wsuggest-attribute=cold \
   -Wsuggest-attribute=const -Wsuggest-attribute=format \
   -Wsuggest-attribute=malloc \
   -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
-  -Wtrampolines -Wundef -Wuninitialized -Wunused \
+  -Wtrampolines -Wundef -Wuninitialized -Wunused-macros \
   -Wvariadic-macros -Wvla -Wwrite-strings \
   -Wno-address -Wno-format-nonliteral -Wno-sign-compare \
   -Wno-type-limits -Wno-unused-parameter
@@ -393,9 +399,10 @@ ZFLAGS=
 ZIC_INSTALL=	$(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS)
 
 # The name of a Posix-compliant 'awk' on your system.
-# Older 'mawk' versions, such as the 'mawk' in Ubuntu 16.04, might dump core;
-# on Ubuntu you can work around this with
-#	AWK=		gawk
+# mawk 1.3.3 and Solaris 10 /usr/bin/awk do not work.
+# Also, it is better (though not essential) if 'awk' supports UTF-8,
+# and unfortunately mawk and busybox awk do not support UTF-8.
+# Try AWK=gawk or AWK=nawk if your awk has the abovementioned problems.
 AWK=		awk
 
 # The full path name of a Posix-compliant shell, preferably one that supports
@@ -460,7 +467,9 @@ OK_LINE=	'^'$(OK_CHAR)'*$$'
 
 # Flags to give 'tar' when making a distribution.
 # Try to use flags appropriate for GNU tar.
-GNUTARFLAGS= --numeric-owner --owner=0 --group=0 --mode=go+u,go-w --sort=name
+GNUTARFLAGS= --format=pax --pax-option='delete=atime,delete=ctime' \
+  --numeric-owner --owner=0 --group=0 \
+  --mode=go+u,go-w --sort=name
 TARFLAGS=	`if tar $(GNUTARFLAGS) --version >/dev/null 2>&1; \
 		 then echo $(GNUTARFLAGS); \
 		 else :; \
@@ -498,7 +507,7 @@ MANTXTS=	newctime.3.txt newstrftime.3.txt newtzset.3.txt \
 			tzfile.5.txt tzselect.8.txt zic.8.txt zdump.8.txt \
 			date.1.txt
 COMMON=		calendars CONTRIBUTING LICENSE Makefile \
-			NEWS README theory.html version
+			NEWS README SECURITY theory.html version
 WEB_PAGES=	tz-art.html tz-how-to.html tz-link.html
 CHECK_WEB_PAGES=check_theory.html check_tz-art.html \
 			check_tz-how-to.html check_tz-link.html
@@ -523,7 +532,7 @@ TZS_YEAR=	2050
 TZS_CUTOFF_FLAG=	-c $(TZS_YEAR)
 TZS=		to$(TZS_YEAR).tzs
 TZS_NEW=	to$(TZS_YEAR)new.tzs
-TZS_DEPS=	$(PRIMARY_YDATA) asctime.c localtime.c \
+TZS_DEPS=	$(YDATA) asctime.c localtime.c \
 			private.h tzfile.h zdump.c zic.c
 # EIGHT_YARDS is just a yard short of the whole ENCHILADA.
 EIGHT_YARDS = $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) tzdata.zi
@@ -533,7 +542,7 @@ ENCHILADA = $(EIGHT_YARDS) $(TZS)
 # This list is not the same as the output of 'git ls-files', since
 # .gitignore is not distributed.
 VERSION_DEPS= \
-		calendars CONTRIBUTING LICENSE Makefile NEWS README \
+		calendars CONTRIBUTING LICENSE Makefile NEWS README SECURITY \
 		africa antarctica asctime.c asia australasia \
 		backward backzone \
 		checklinks.awk checktab.awk \
@@ -736,7 +745,7 @@ date:		$(DATEOBJS)
 tzselect:	tzselect.ksh version
 		VERSION=`cat version` && sed \
 			-e 's|#!/bin/bash|#!$(KSHELL)|g' \
-			-e 's|AWK=[^}]*|AWK=$(AWK)|g' \
+			-e 's|AWK=[^}]*|AWK='\''$(AWK)'\''|g' \
 			-e 's|\(PKGVERSION\)=.*|\1='\''($(PACKAGE)) '\''|' \
 			-e 's|\(REPORT_BUGS_TO\)=.*|\1=$(BUGEMAIL)|' \
 			-e 's|TZDIR=[^}]*|TZDIR=$(TZDIR)|' \
@@ -757,7 +766,7 @@ check_character_set: $(ENCHILADA)
 		sharp='#' && \
 		! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \
 			$(MISC) $(SOURCES) $(WEB_PAGES) \
-			CONTRIBUTING LICENSE README \
+			CONTRIBUTING LICENSE README SECURITY \
 			version tzdata.zi && \
 		! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \
 			Makefile && \
@@ -796,9 +805,10 @@ check_links:	checklinks.awk $(TDATA_TO_CHECK) tzdata.zi
 		$(AWK) -f checklinks.awk tzdata.zi
 		touch $@
 
-check_tables:	checktab.awk $(PRIMARY_YDATA) $(ZONETABLES)
+check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)
 		for tab in $(ZONETABLES); do \
-		  $(AWK) -f checktab.awk -v zone_table=$$tab $(PRIMARY_YDATA) \
+		  test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \
+		  $(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \
 		    || exit; \
 		done
 		touch $@
@@ -952,6 +962,12 @@ check_public: $(VERSION_DEPS)
 		  public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \
 		done
 		public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK)
+		:
+		: Also check 'backzone' syntax.
+		rm public.dir/main.zi
+		cd public.dir && $(MAKE) PACKRATDATA=backzone main.zi
+		public.dir/zic -d public.dir/zoneinfo main.zi
+		:
 		rm -fr public.dir
 		touch $@
 
@@ -964,7 +980,7 @@ $(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
 		mkdir [email protected]
 		ln $(VERSION_DEPS) [email protected]
 		case $@ in \
-		  int32_t) range=-2147483648,2147483648;; \
+		  int*32_t) range=-2147483648,2147483648;; \
 		  u*) range=0,4294967296;; \
 		  *) range=-4294967296,4294967296;; \
 		esac && \