From b729fff4a3e1fcadf581a525af6b09b4f5696228 Mon Sep 17 00:00:00 2001
From: Cosmin Truta <ctruta@gmail.com>
Date: Sat, 28 Jul 2018 23:39:55 -0400
Subject: [PATCH] Remove the Y2K compliance statement

As of July 2018, this statement is no longer necessary.
---
 README                       |  1 -
 png.h                        | 57 ------------------------------------
 scripts/makefile.32sunu      |  2 +-
 scripts/makefile.64sunu      |  2 +-
 scripts/makefile.darwin      |  2 +-
 scripts/makefile.freebsd     |  2 +-
 scripts/makefile.hp64        |  2 +-
 scripts/makefile.hpgcc       |  2 +-
 scripts/makefile.hpux        |  2 +-
 scripts/makefile.knr         |  2 +-
 scripts/makefile.linux       |  2 +-
 scripts/makefile.linux-opt   |  2 +-
 scripts/makefile.mips        |  2 +-
 scripts/makefile.openbsd     |  2 +-
 scripts/makefile.sco         |  2 +-
 scripts/makefile.sggcc       |  2 +-
 scripts/makefile.sgi         |  2 +-
 scripts/makefile.so9         |  2 +-
 scripts/makefile.solaris     |  2 +-
 scripts/makefile.solaris-x86 |  2 +-
 scripts/makefile.std         |  2 +-
 scripts/makefile.sunos       |  2 +-
 22 files changed, 20 insertions(+), 78 deletions(-)

diff --git a/README b/README
index bf63f70f0..925fd8c6b 100644
--- a/README
+++ b/README
@@ -147,7 +147,6 @@ Files in this distribution:
       LICENSE       =>  License to use and redistribute libpng
       README        =>  This file
       TODO          =>  Things not implemented in the current library
-      Y2KINFO       =>  Statement of Y2K compliance
       example.c     =>  Example code for using libpng functions
       libpng.3      =>  manual page for libpng (includes libpng-manual.txt)
       libpng-manual.txt  =>  Description of libpng and its functions
diff --git a/png.h b/png.h
index e6985a315..1e1b45eaa 100644
--- a/png.h
+++ b/png.h
@@ -243,63 +243,6 @@
  * <https://www.w3.org/TR/2003/REC-PNG-20031110/
  */
 
-/*
- * Y2K compliance in libpng:
- * =========================
- *
- *    July 15, 2018
- *
- *    Since the PNG Development group is an ad-hoc body, we can't make
- *    an official declaration.
- *
- *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.35 are Y2K compliant.  It is my belief that
- *    earlier versions were also Y2K compliant.
- *
- *    Libpng only has two year fields.  One is a 2-byte unsigned integer
- *    that will hold years up to 65535.  The other, which is deprecated,
- *    holds the date in text format, and will hold years up to 9999.
- *
- *    The integer is
- *        "png_uint_16 year" in png_time_struct.
- *
- *    The string is
- *        "char time_buffer[29]" in png_struct.  This is no longer used
- *    in libpng-1.6.x and will be removed from libpng-1.7.0.
- *
- *    There are seven time-related functions:
- *        png.c: png_convert_to_rfc_1123_buffer() in png.c
- *          (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
- *          png_convert_to_rfc_1152() in error prior to libpng-0.98)
- *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
- *        png_convert_from_time_t() in pngwrite.c
- *        png_get_tIME() in pngget.c
- *        png_handle_tIME() in pngrutil.c, called in pngread.c
- *        png_set_tIME() in pngset.c
- *        png_write_tIME() in pngwutil.c, called in pngwrite.c
- *
- *    All handle dates properly in a Y2K environment.  The
- *    png_convert_from_time_t() function calls gmtime() to convert from system
- *    clock time, which returns (year - 1900), which we properly convert to
- *    the full 4-digit year.  There is a possibility that libpng applications
- *    are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
- *    function, or that they are incorrectly passing only a 2-digit year
- *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
- *    but this is not under our control.  The libpng documentation has always
- *    stated that it works with 4-digit years, and the APIs have been
- *    documented as such.
- *
- *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
- *    integer to hold the year, and can hold years as large as 65535.
- *
- *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
- *    no date-related code.
- *
- *       Glenn Randers-Pehrson
- *       libpng maintainer
- *       PNG Development Group
- */
-
 #ifndef PNG_H
 #define PNG_H
 
diff --git a/scripts/makefile.32sunu b/scripts/makefile.32sunu
index 7d4b7c53a..c849ecd27 100644
--- a/scripts/makefile.32sunu
+++ b/scripts/makefile.32sunu
@@ -219,7 +219,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.64sunu b/scripts/makefile.64sunu
index 341fce969..8880fa9b9 100644
--- a/scripts/makefile.64sunu
+++ b/scripts/makefile.64sunu
@@ -219,7 +219,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.darwin b/scripts/makefile.darwin
index be3f92c54..33c27cc1f 100644
--- a/scripts/makefile.darwin
+++ b/scripts/makefile.darwin
@@ -200,7 +200,7 @@ clean:
 	$(RM_F) *.o libpng.a pngtest pngout.png libpng-config \
 	libpng.pc $(LIBNAME).*dylib pngtesti pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.freebsd b/scripts/makefile.freebsd
index cad1a5aa8..5fec61e35 100644
--- a/scripts/makefile.freebsd
+++ b/scripts/makefile.freebsd
@@ -62,7 +62,7 @@ test: pngtest
 pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 	cp $(PNGLIBCONF_H_PREBUILT) $@
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.hp64 b/scripts/makefile.hp64
index 5948be8ec..cde0d1553 100644
--- a/scripts/makefile.hp64
+++ b/scripts/makefile.hp64
@@ -206,7 +206,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.hpgcc b/scripts/makefile.hpgcc
index 5c8791b13..efef1f3fb 100644
--- a/scripts/makefile.hpgcc
+++ b/scripts/makefile.hpgcc
@@ -209,7 +209,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.hpux b/scripts/makefile.hpux
index b07612dc7..448975741 100644
--- a/scripts/makefile.hpux
+++ b/scripts/makefile.hpux
@@ -204,7 +204,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.knr b/scripts/makefile.knr
index d8de064c4..307453fb5 100644
--- a/scripts/makefile.knr
+++ b/scripts/makefile.knr
@@ -91,7 +91,7 @@ install: libpng.a png.h pngconf.h pnglibconf.h
 clean:
 	$(RM_F) *.o libpng.a pngtest pngout.png ansi2knr pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.linux b/scripts/makefile.linux
index 7b6f5a7f9..f4ed37f68 100644
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -222,7 +222,7 @@ clean:
 	$(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.linux-opt b/scripts/makefile.linux-opt
index f7ef4bc53..76f6d1afc 100644
--- a/scripts/makefile.linux-opt
+++ b/scripts/makefile.linux-opt
@@ -232,7 +232,7 @@ clean:
 	$(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.mips b/scripts/makefile.mips
index 5633608c8..0357ae81c 100644
--- a/scripts/makefile.mips
+++ b/scripts/makefile.mips
@@ -78,7 +78,7 @@ install: libpng.a
 clean:
 	rm -f *.o libpng.a pngtest pngout.png pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.openbsd b/scripts/makefile.openbsd
index c4cfb2b4a..4057b2ee8 100644
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -28,7 +28,7 @@ NOPROFILE= Yes
 CLEANFILES+= pngtest.o pngtest pnglibconf.h
 
 MAN=	libpng.3 libpngpf.3 png.5
-DOCS=	ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
+DOCS=	ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO \
 	libpng-manual.txt
 
 # Pre-built configuration
diff --git a/scripts/makefile.sco b/scripts/makefile.sco
index 67d84aaac..01d7eaaaa 100644
--- a/scripts/makefile.sco
+++ b/scripts/makefile.sco
@@ -201,7 +201,7 @@ clean:
 	$(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
 	pnglibconf.h libpng.pc
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.sggcc b/scripts/makefile.sggcc
index a0d051dbd..82efe7a22 100644
--- a/scripts/makefile.sggcc
+++ b/scripts/makefile.sggcc
@@ -211,7 +211,7 @@ clean:
 	$(RM_F) libpng.a pngtest pngtesti pngout.png libpng.pc \
 	so_locations libpng-config $(LIBSO) $(LIBSOMAJ)* pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.sgi b/scripts/makefile.sgi
index 7df090222..5d9c23fa9 100644
--- a/scripts/makefile.sgi
+++ b/scripts/makefile.sgi
@@ -212,7 +212,7 @@ clean:
 	$(LIBSO) $(LIBSOMAJ)* \
 	so_locations pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.so9 b/scripts/makefile.so9
index ba9308c8a..93166f30e 100644
--- a/scripts/makefile.so9
+++ b/scripts/makefile.so9
@@ -222,7 +222,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.solaris b/scripts/makefile.solaris
index 8a450d371..6f4ba6418 100644
--- a/scripts/makefile.solaris
+++ b/scripts/makefile.solaris
@@ -219,7 +219,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.solaris-x86 b/scripts/makefile.solaris-x86
index 2ee3c14a5..4c07b0670 100644
--- a/scripts/makefile.solaris-x86
+++ b/scripts/makefile.solaris-x86
@@ -218,7 +218,7 @@ clean:
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.std b/scripts/makefile.std
index ee6a86835..30ab46701 100644
--- a/scripts/makefile.std
+++ b/scripts/makefile.std
@@ -109,7 +109,7 @@ clean:
 	$(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.h pnglibconf.c \
 	pnglibconf.out
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*
 
diff --git a/scripts/makefile.sunos b/scripts/makefile.sunos
index efe308c47..9a0e28e72 100644
--- a/scripts/makefile.sunos
+++ b/scripts/makefile.sunos
@@ -90,7 +90,7 @@ install: libpng.a
 clean:
 	$(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.h
 
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO
 writelock:
 	chmod a-w *.[ch35] $(DOCS) scripts/*