Imported from libpng-1.0.3.tar

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "January 6, 1999"
+.TH LIBPNG 3 "January 14, 1999"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.0.2b - January 6, 1999
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.3 - January 14, 1999
 .SH SYNOPSIS
 
 #include <png.h>
@@ -423,10 +423,10 @@ Following is a copy of the libpng.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.0.2b - January 6, 1999
+ libpng version 1.0.3 - January 14, 1999
  Updated and distributed by Glenn Randers-Pehrson
  <randeg@alumni.rpi.edu>
- Copyright (c) 1998, 1999, Glenn Randers-Pehrson
+ Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
@@ -2437,6 +2437,58 @@ png_set_error_fn(), which is essentially the same function, but with a
 new name to force compilation errors with applications that try to use
 the old method.
 
+.SH VII. Y2K Compliance in libpng
+
+January 13, 1999
+
+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 0.81 and
+upward are Y2K compliant.  It is my belief that earlier versions were
+also Y2K compliant.
+
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+    "png_uint_16 year" in png_time_struct.
+
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+    png_convert_to_rfc_1123() in png.c 
+      (formerly png_convert_to_rfc_1152() in error)
+    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 appear to 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 applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or 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.
+
+
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group
+
 .SH NOTE
 
 Note about libpng version numbers:
@@ -2522,7 +2574,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
   
-Libpng version 1.0.2b - January 6, 1999:
+Libpng version 1.0.3 - January 14, 1999:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (randeg@alumni.rpi.edu).
 
@@ -2534,7 +2586,7 @@ Supported by the PNG development group
 
 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
 Copyright (c) 1996, 1997 Andreas Dilger
-Copyright (c) 1998, 1999, Glenn Randers-Pehrson
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson
 
 The PNG Reference Library (libpng) is supplied "AS IS".  The Contributing
 Authors and Group 42, Inc. disclaim all warranties, expressed or implied,