Imported from libpng-1.0.1.tarv1.0.1

28 files changed, 74 insertions, 87 deletions

diff --git a/CHANGES b/CHANGES
index b29c65b1c..9cb33a1e8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -281,3 +281,8 @@ version 1.0.0a [March 9, 1998]
 version 1.0.0b [March 13, 1998]
    Quieted compiler complaints about two empty "for" loops in pngrutil.c
    Minor changes to makefile.s2x
+   Removed #ifdef/#endif around a png_free() in pngread.c
+version 1.0.1 [March 14, 1998]
+   Changes makefile.s2x to reduce security risk of using a relative pathname
+   Fixed some typos in the documentation (Greg).
+   Fixed a problem with value of "channels" returned by png_read_update_info()
diff --git a/INSTALL b/INSTALL
index f1ecdffca..497874099 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,5 +1,5 @@
 
-Installing libpng version 1.0.0b March 13, 1998
+Installing libpng version 1.0.1 March 15, 1998
 
 Before installing libpng, you must first install zlib.  zlib
 can usually be found wherever you got libpng.  zlib can be
@@ -10,7 +10,7 @@ zlib.h and zconf.h include files that correspond to the
 version of zlib that's installed.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-1.0.0b or "lpng100" and "zlib-1.1.1"
+might be called "libpng-1.0.1 or "lpng100" and "zlib-1.1.1"
 or "zlib111") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
diff --git a/README b/README
index 93744158f..ea463cd9c 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-README for libpng 1.0.0b (shared library 2.1)
+README for libpng 1.0.1 (shared library 2.1)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
diff --git a/TODO b/TODO
index 21f963a8c..562859a22 100644
--- a/TODO
+++ b/TODO
@@ -2,6 +2,7 @@ TODO - list of things to do for libpng
 
 fix problem with C++ and EXTERN "C"
 add "grayscale->palette" transformation and "palette->grayscale" detection
+add "grayscale" -> "grayscale+alpha" and "grayscale+FILLER" transformations
 improved dithering
 multi-lingual error and warning message support
 sPLT chunk handling
diff --git a/libpng-1.0.0b b/libpng-1.0.0b
deleted file mode 120000
index 848ef9fd1..000000000
--- a/libpng-1.0.0b
+++ /dev/null
@@ -1 +0,0 @@
-libpng-1.0.0b
\ No newline at end of file
diff --git a/libpng.3 b/libpng.3
index 56d3e9c2a..88d8c9642 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "March 13, 1998"
+.TH LIBPNG 3 "March 15, 1998"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library
 .SH SYNOPSIS
@@ -396,7 +396,7 @@ 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 1.0.0b March 13, 1998
+ libpng version 1.0.1 March 15, 1998
  Updated and distributed by Glenn Randers-Pehrson
  <randeg@alumni.rpi.edu>
  Copyright (c) 1998, Glenn Randers-Pehrson
@@ -2298,13 +2298,13 @@ the first widely used release:
    0.90       0.90        90  0.90  [should be 2.0.90]
    0.95       0.95        95  0.95  [should be 2.0.95]
    0.96       0.96        96  0.96  [should be 2.0.96]
-   0.97b 7")  1.00.97     97  1.0.1 [should be 2.0.97]
+   0.97b      1.00.97     97  1.0.1 [should be 2.0.97]
    0.97c      0.97        97  2.0.97
    0.98       0.98        98  2.0.98
    0.99       0.99        98  2.0.99
    0.99a-m    0.99        99  2.0.99
-   1.00       1.00       100  2.1.0 [should be 10000]
-   1.0.0      1.0.0      100  2.1.0 [should be 10000]
+   1.00       1.00       100  2.1.0 [int should be 10000]
+   1.0.0      1.0.0      100  2.1.0 [int should be 10000]
    1.0.1      1.0.1    10001  2.1.0
 
 Henceforth the source version will match the shared-library
@@ -2312,7 +2312,7 @@ minor and patch numbers; the shared-library major version number will be
 used for changes in backward compatibility, as it is intended.
 The PNG_PNGLIB_VER macro, which is not used within libpng but
 is available for applications, is an unsigned integer of the form
-xyyzz corresponding to the source version x.y.z (leading zeros in y and z)
+xyyzz corresponding to the source version x.y.z (leading zeros in y and z).
  
 .SH "SEE ALSO"
 libpngpf(3), png(5)
@@ -2366,7 +2366,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
   
-Libpng version 1.0.0b March 13, 1998:
+Libpng version 1.0.1 March 15, 1998:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (randeg@alumni.rpi.edu).
 
diff --git a/libpng.txt b/libpng.txt
index cc580117b..df8f4e642 100644
--- a/libpng.txt
+++ b/libpng.txt
@@ -1,6 +1,6 @@
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.0.0b March 13, 1998
+ libpng version 1.0.1 March 15, 1998
  Updated and distributed by Glenn Randers-Pehrson
  <randeg@alumni.rpi.edu>
  Copyright (c) 1998, Glenn Randers-Pehrson
diff --git a/libpngpf.3 b/libpngpf.3
index 4458ba882..7ba582ebe 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,4 +1,4 @@
-.TH LIBPNGPF 3 "March 13, 1998"
+.TH LIBPNGPF 3 "March 15, 1998"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library
 (private functions)
diff --git a/png.5 b/png.5
index cc2149f63..30244aabb 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "March 13, 1998"
+.TH PNG 5 "March 15, 1998"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index 0b72600d1..127b47b68 100644
--- a/png.c
+++ b/png.c
@@ -1,12 +1,12 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
@@ -16,7 +16,7 @@
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
  */
-char png_libpng_ver[12] = "1.0.0b";
+char png_libpng_ver[12] = "1.0.1";
 
 /* Place to hold the signature string for a PNG file. */
 png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
diff --git a/png.h b/png.h
index 0b6ab7b62..36541e916 100644
--- a/png.h
+++ b/png.h
@@ -1,12 +1,12 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see the COPYRIGHT NOTICE below.
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998 Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * Note about libpng version numbers:
  *
@@ -37,7 +37,7 @@
  *    used for changes in backward compatibility, as it is intended.
  *    The PNG_PNGLIB_VER macro, which is not used within libpng but
  *    is available for applications, is an unsigned integer of the form
- *    xyyzz corresponding to the source version x.y.z (leading zeros in y and z)
+ *    xyyzz corresponding to the source version x.y.z (leading zeros in y and z).
  *    
  *
  * See libpng.txt for more information.  The PNG specification is available
@@ -118,13 +118,13 @@ extern "C" {
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.0.0b"
+#define PNG_LIBPNG_VER_STRING "1.0.1"
 
-/* Gareful here.  At one time, Guy wanted to use 082, but that would be octal.
- * We must not include leading zeroes.
+/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
+ * We must not include leading zeros.
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
- * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z-bugfix*/
+ * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=bugfix */
 #define PNG_LIBPNG_VER    10001  /* 1.0.1 */
 
 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
diff --git a/pngconf.h b/pngconf.h
index 9331a2c1b..675f292ba 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,12 +1,12 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 /* Any machine specific code is near the front of this file, so if you
diff --git a/pngerror.c b/pngerror.c
index 74b27334a..9bf58a4a5 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -1,12 +1,12 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file provides a location for all error handling.  Users which
  * need special error handling are expected to write replacement functions
diff --git a/pngget.c b/pngget.c
index 3c066792c..eb2f64fad 100644
--- a/pngget.c
+++ b/pngget.c
@@ -1,12 +1,12 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
diff --git a/pngmem.c b/pngmem.c
index 53d5c17c8..2fa3627dc 100644
--- a/pngmem.c
+++ b/pngmem.c
@@ -1,12 +1,12 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file provides a location for all memory allocation.  Users which
  * need special memory handling are expected to modify the code in this file
diff --git a/pngpread.c b/pngpread.c
index dad9a91fb..0f0d466fa 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,12 +1,12 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
diff --git a/pngread.c b/pngread.c
index 92c068a5a..1618b7309 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1,12 +1,12 @@
 
 /* pngread.c - read a PNG file
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file contains routines that an application calls directly to
  * read a PNG file or stream.
@@ -123,7 +123,7 @@ png_read_init(png_structp png_ptr)
 }
 
 /* Read the information before the actual image data.  This has been
- * changed in v0.90 to allow reading a file which already has the magic
+ * changed in v0.90 to allow reading a file that already has the magic
  * bytes read from the stream.  You can tell libpng how many bytes have
  * been read from the beginning of the stream (up to the maxumum of 8)
  * via png_set_sig_bytes(), and we will only check the remaining bytes
diff --git a/pngrio.c b/pngrio.c
index 0d9bd8a6e..7adb48f54 100644
--- a/pngrio.c
+++ b/pngrio.c
@@ -1,12 +1,12 @@
 
 /* pngrio.c - functions for data input
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file provides a location for all input.  Users which need
  * special handling are expected to write a function which has the same
diff --git a/pngrtran.c b/pngrtran.c
index 3db732634..885af5390 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,12 +1,12 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file contains functions optionally called by an application 
  * in order to tell libpng how to handle data when reading a PNG.
@@ -665,7 +665,6 @@ png_init_read_transformations(png_structp png_ptr)
         if (png_ptr->transformations & PNG_INVERT_ALPHA)
         {
 #if defined(PNG_READ_EXPAND_SUPPORTED)
-           /* GRR BUG #1:  was (png_ptr->transformations & !PNG_EXPAND) */
            if (!(png_ptr->transformations & PNG_EXPAND))
 #endif
            {
@@ -715,11 +714,6 @@ png_init_read_transformations(png_structp png_ptr)
             {
                double g, gs;
 
-/*
-               GRR BUG #3:  inconsistent with handling of full RGBA below
-               g = 1.0 / png_ptr->background_gamma;
-               gs = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
- */
                switch (png_ptr->background_gamma_type)
                {
                   case PNG_BACKGROUND_GAMMA_SCREEN:
@@ -740,17 +734,7 @@ png_init_read_transformations(png_structp png_ptr)
                      gs = 1.0;   /* back */
                }
 
-               if (
-/*
-                   GRR BUG #2:  This creates self-inconsistent images--fully
-                     transparent and fully opaque look fine, but translucent
-                     pixels are wrong (too bright if XV's code can be trusted).
-                     Commenting it out makes an internally self-consistent
-                     image, but still not consistent with RGBA version of same
-                     thing (again, too bright in XV).
-                   png_ptr->background_gamma_type==PNG_BACKGROUND_GAMMA_SCREEN||
- */
-                   fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
+               if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
                {
                   back.red   = (png_byte)png_ptr->background.red;
                   back.green = (png_byte)png_ptr->background.green;
@@ -1005,8 +989,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 #endif
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
-      !(info_ptr->color_type & PNG_COLOR_MASK_COLOR))
+   if (png_ptr->transformations & PNG_GRAY_TO_RGB)
       info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
 #endif
 
@@ -1018,12 +1001,8 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
       info_ptr->channels = 1;
 
 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
-       info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
-   {
-      info_ptr->channels--;
+   if (png_ptr->transformations & PNG_STRIP_ALPHA)
       info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
-   }
 #endif
 
 #if defined(PNG_READ_FILLER_SUPPORTED)
diff --git a/pngrutil.c b/pngrutil.c
index 3591b0e8c..1c3790693 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -1,12 +1,12 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file contains routines which are only called from within
  * libpng itself during the course of reading an image.
@@ -1114,7 +1114,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 
    for (buf = units; *buf != 0x00; buf++)
-   /* Empty loop to move past the units string. */ ;
+      /* Empty loop to move past the units string. */ ;
 
    png_debug(3, "Allocating pCAL parameters array\n");
    params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams
@@ -1127,7 +1127,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
       png_debug1(3, "Reading pCAL parameter %d\n", i);
       for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
-      /* Empty loop to move past each parameter string */ ;
+         /* Empty loop to move past each parameter string */ ;
 
       /* Make sure we haven't run out of data yet */
       if (buf > endptr)
diff --git a/pngset.c b/pngset.c
index c68431b0c..aa85f24b6 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,12 +1,12 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * The functions here are used during reads to store data from the file
  * into the info struct, and during writes to store application data
diff --git a/pngtest.c b/pngtest.c
index 215c3ad2e..22cbcb3ea 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,12 +1,12 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This program reads in a PNG image, writes it out again, and then
  * compares the two files.  If the files are identical, this shows that
diff --git a/pngtrans.c b/pngtrans.c
index 2d83ca8fd..d38dbd19d 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -1,12 +1,12 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
diff --git a/pngwio.c b/pngwio.c
index 17a087f1f..444a123b5 100644
--- a/pngwio.c
+++ b/pngwio.c
@@ -1,12 +1,12 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  *
  * This file provides a location for all output.  Users which need
  * special handling are expected to write functions which have the same
diff --git a/pngwrite.c b/pngwrite.c
index c2f9d6a31..9980027e3 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,12 +1,12 @@
    
 /* pngwrite.c - general routines to write a PNG file
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 /* get internal access to png.h */
diff --git a/pngwtran.c b/pngwtran.c
index fa2750654..d85e01536 100644
--- a/pngwtran.c
+++ b/pngwtran.c
@@ -1,12 +1,12 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
diff --git a/pngwutil.c b/pngwutil.c
index 775f3da8b..492bde7bb 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1,12 +1,12 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * libpng 1.0.0b
+ * libpng 1.0.1
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 13, 1998
+ * March 15, 1998
  */
 
 #define PNG_INTERNAL
diff --git a/scripts/makefile.s2x b/scripts/makefile.s2x
index 1a34a17f9..163f36382 100644
--- a/scripts/makefile.s2x
+++ b/scripts/makefile.s2x
@@ -7,10 +7,13 @@
 CC=gcc
 
 # Where the zlib library and include files are located
-# ZLIBLIB=/usr/local/lib
-# ZLIBINC=/usr/local/include
-ZLIBLIB=../zlib
-ZLIBINC=../zlib
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
 
 
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \