[libpng16] Reverted the fix of byte order in png_do_read_filler() with 16-bit

input that was made in version 1.6.17beta01, to preserve legacy
behavior even though it was incorrect.  Instead, added new API
png_set_filter_16() and png_set_add_alpha_16() that set a flag to
make png_do_read_filter() interpret the filler bytes properly.

13 files changed, 141 insertions, 65 deletions

diff --git a/ANNOUNCE b/ANNOUNCE
index 5658bbc98..191a07c4d 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.19beta03 - September 20, 2015
+Libpng 1.6.19beta03 - September 24, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -64,7 +64,7 @@ Version 1.6.19beta02 [August 19, 2015]
     in ANSI-C (unlike 0x80000000 in the signed case) the checking that
     occurs later can catch them (John Bowler).
 
-Version 1.6.19beta03 [September 20, 2015]
+Version 1.6.19beta03 [September 24, 2015]
   Fixed png_save_int_32 when int is not 2's complement (John Bowler).
   Updated libpng16 with all the recent test changes from libpng17,
     including changes to pngvalid.c to ensure that the original,
@@ -83,6 +83,11 @@ Version 1.6.19beta03 [September 20, 2015]
     slightly different error limits this simplifies maintenance. The
     makepngs.sh script has also been updated to more accurately reflect
     current problems in libpng 1.7 (John Bowler).
+  Reverted the fix of byte order in png_do_read_filler() with 16-bit
+    input that was made in version 1.6.17beta01, to preserve legacy
+    behavior even though it was incorrect.  Instead, added new API
+    png_set_filter_16() and png_set_add_alpha_16() that set a flag to
+    make png_do_read_filter() interpret the filler bytes properly.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 735123cd7..36c3bcddc 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5347,7 +5347,7 @@ Version 1.6.19beta02 [August 19, 2015]
     in ANSI-C (unlike 0x80000000 in the signed case) the checking that
     occurs later can catch them (John Bowler).
 
-Version 1.6.19beta03 [September 20, 2015]
+Version 1.6.19beta03 [September 24, 2015]
   Fixed png_save_int_32 when int is not 2's complement (John Bowler).
   Updated libpng16 with all the recent test changes from libpng17,
     including changes to pngvalid.c to ensure that the original,
@@ -5366,6 +5366,11 @@ Version 1.6.19beta03 [September 20, 2015]
     slightly different error limits this simplifies maintenance. The
     makepngs.sh script has also been updated to more accurately reflect
     current problems in libpng 1.7 (John Bowler).
+  Reverted the fix of byte order in png_do_read_filler() with 16-bit
+    input that was made in version 1.6.17beta01, to preserve legacy
+    behavior even though it was incorrect.  Instead, added new API
+    png_set_filter_16() and png_set_add_alpha_16() that set a flag to
+    make png_do_read_filter() interpret the filler bytes properly.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 5fa363a66..37f508363 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.24 [(PENDING RELEASE)]
  * Copyright (c) 2014-2015 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -3578,7 +3578,7 @@ check_interlace_type(int const interlace_type)
 #define CAN_WRITE_INTERLACE\
    PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
 
-/* Make a standardized image given a an image colour type, bit depth and
+/* Make a standardized image given an image colour type, bit depth and
  * interlace type.  The standard images have a very restricted range of
  * rows and heights and are used for testing transforms rather than image
  * layout details.  See make_size_images below for a way to make images
@@ -8039,7 +8039,7 @@ image_transform_png_set_filler_set(const image_transform *this,
    RANDOMIZE(data.filler);
    data.flags = random_choice();
 
-   png_set_filler(pp, data.filler, data.flags);
+   png_set_filler_16(pp, data.filler, data.flags);
 
    /* The standard display handling stuff also needs to know that
     * there is a filler, so set that here.
@@ -8112,7 +8112,7 @@ image_transform_png_set_add_alpha_set(const image_transform *this,
    RANDOMIZE(data.filler);
    data.flags = random_choice();
 
-   png_set_add_alpha(pp, data.filler, data.flags);
+   png_set_add_alpha_16(pp, data.filler, data.flags);
    this->next->set(this->next, that, pp, pi);
 }
 
diff --git a/example.c b/example.c
index 0a241413b..902b6c584 100644
--- a/example.c
+++ b/example.c
@@ -522,7 +522,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
    png_set_swap(png_ptr);
 
    /* Add filler (or alpha) byte (before/after each RGB triplet) */
-   png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+   png_set_filler_16(png_ptr, 0xffff, PNG_FILLER_AFTER);
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Turn on interlace handling.  REQUIRED if you are not using
@@ -958,7 +958,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
     * RGB (4 channels -> 3 channels). The second parameter is not used.
     */
-   png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+   png_set_filler_16(png_ptr, 0, PNG_FILLER_BEFORE);
 
    /* Flip BGR pixels to RGB */
    png_set_bgr(png_ptr);
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 90b5610c1..7ff1b675b 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.19beta03 - August 19, 2015
+ libpng version 1.6.19beta03 - September 24, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.19beta03 - August 19, 2015
+ libpng versions 0.97, January 1998, through 1.6.19beta03 - September 24, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -1685,17 +1685,21 @@ described below.
 Data will be decoded into the supplied row buffers packed into bytes
 unless the library has been told to transform it into another format.
 For example, 4 bit/pixel paletted or grayscale data will be returned
-2 pixels/byte with the leftmost pixel in the high-order bits of the
-byte, unless png_set_packing() is called.  8-bit RGB data will be stored
-in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+2 pixels/byte with the leftmost pixel in the high-order bits of the byte,
+unless png_set_packing() is called.  8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler_16() or png_set_add_alpha_16()
 is called to insert filler bytes, either before or after each RGB triplet.
+
 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
 byte of the color value first, unless png_set_scale_16() is called to
-transform it to regular RGB RGB triplets, or png_set_filler() or
-png_set_add alpha() is called to insert filler bytes, either before or
-after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
-be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
-or png_set_scale_16().
+transform it to regular RGB RGB triplets, or png_set_filler_16() or
+png_set_add alpha_16() is called to insert trwo filler bytes, either before
+or after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data
+can be modified with png_set_filler_16(), png_set_add_alpha_16(),
+png_set_strip_16(), or png_set_scale_16().  Note that png_set_filler_16()
+and png_set_add_alpha_16(), which can be used with either 8-bit or 16-bit
+images have replaced the png_set_filler() and png_set_add_alpha() functions,
+which only work properly with 8-bit data.
 
 The following code transforms grayscale images of less than 8 to 8 bits,
 changes paletted images to RGB, and adds a full alpha channel if there is
@@ -1785,7 +1789,7 @@ Within the matrix,
      "-" means the transformation is not supported.
      "." means nothing is necessary (a tRNS chunk can just be ignored).
      "t" means the transformation is obtained by png_set_tRNS.
-     "A" means the transformation is obtained by png_set_add_alpha().
+     "A" means the transformation is obtained by png_set_add_alpha_16().
      "X" means the transformation is obtained by png_set_expand().
      "1" means the transformation is obtained by
          png_set_expand_gray_1_2_4_to_8() (and by png_set_expand()
@@ -1848,24 +1852,26 @@ PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
 into 4 or 8 bytes for windowing systems that need them in this format:
 
     if (color_type == PNG_COLOR_TYPE_RGB)
-       png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+       png_set_filler_16(png_ptr, filler, PNG_FILLER_BEFORE);
 
-where "filler" is the 8 or 16-bit number to fill with, and the location is
-either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+where "filler" is the 8-bit or 16-bit number to fill with, and the location
+is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
 you want the filler before the RGB or after.  This transformation
 does not affect images that already have full alpha channels.  To add an
-opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+opaque alpha channel, use filler=0xffff and PNG_FILLER_AFTER which
 will generate RGBA pixels.
 
-Note that png_set_filler() does not change the color type.  If you want
+Note that png_set_filler_16() does not change the color type.  If you want
 to do that, you can add a true alpha channel with
 
     if (color_type == PNG_COLOR_TYPE_RGB ||
        color_type == PNG_COLOR_TYPE_GRAY)
-       png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+       png_set_add_alpha_16(png_ptr, filler, PNG_FILLER_AFTER);
 
 where "filler" contains the alpha value to assign to each pixel.
-This function was added in libpng-1.2.7.
+The png_set_alpha() function was added in libpng-1.2.7 and the
+png_set_alpha_16() function, which can be used for either 8-bit or
+16-bit images, was added in libpng-1.5.24.
 
 If you are reading an image with an alpha channel, and you need the
 data as ARGB instead of the normal PNG format RGBA:
@@ -4904,7 +4910,13 @@ limits are now
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
 The png_set_option() function (and the "options" member of the png struct) was
-added to libpng-1.5.15.
+added to libpng-1.5.15, with option PNG_ARM_NEON.
+
+The png_set_filler_16() and png_set_add_alpha_16() functions were added
+at libpng-1.5.24 and libpng-1.6.19.  These replace the png_set_filler(() and
+the png_set_add_alpha() functions, which did not work properly with 16-bit
+images.  The new functions can be used with either 8-bit or 16-bit images,
+while the old functions are still available for use only with 8-bit images.
 
 The library now supports a complete fixed point implementation and can
 thus be used on systems that have no floating point support or very
@@ -5312,7 +5324,7 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVI. Y2K Compliance in libpng
 
-August 19, 2015
+September 24, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
diff --git a/libpng.3 b/libpng.3
index c71ff4822..82802642d 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "August 19, 2015"
+.TH LIBPNG 3 "September 24, 2015"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.6.19beta03
 .SH SYNOPSIS
@@ -277,6 +277,8 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.19beta03
 
 \fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
 
+\fBvoid png_set_add_alpha_16 (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+
 \fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP
 
 \fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP
@@ -325,6 +327,8 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.19beta03
 
 \fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
 
+\fBvoid png_set_filler_16 (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+
 \fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
 
 \fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
@@ -508,7 +512,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.19beta03 - August 19, 2015
+ libpng version 1.6.19beta03 - September 24, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
@@ -519,7 +523,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.19beta03 - August 19, 2015
+ libpng versions 0.97, January 1998, through 1.6.19beta03 - September 24, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -2193,17 +2197,21 @@ described below.
 Data will be decoded into the supplied row buffers packed into bytes
 unless the library has been told to transform it into another format.
 For example, 4 bit/pixel paletted or grayscale data will be returned
-2 pixels/byte with the leftmost pixel in the high-order bits of the
-byte, unless png_set_packing() is called.  8-bit RGB data will be stored
-in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+2 pixels/byte with the leftmost pixel in the high-order bits of the byte,
+unless png_set_packing() is called.  8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler_16() or png_set_add_alpha_16()
 is called to insert filler bytes, either before or after each RGB triplet.
+
 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
 byte of the color value first, unless png_set_scale_16() is called to
-transform it to regular RGB RGB triplets, or png_set_filler() or
-png_set_add alpha() is called to insert filler bytes, either before or
-after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
-be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
-or png_set_scale_16().
+transform it to regular RGB RGB triplets, or png_set_filler_16() or
+png_set_add alpha_16() is called to insert trwo filler bytes, either before
+or after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data
+can be modified with png_set_filler_16(), png_set_add_alpha_16(),
+png_set_strip_16(), or png_set_scale_16().  Note that png_set_filler_16()
+and png_set_add_alpha_16(), which can be used with either 8-bit or 16-bit
+images have replaced the png_set_filler() and png_set_add_alpha() functions,
+which only work properly with 8-bit data.
 
 The following code transforms grayscale images of less than 8 to 8 bits,
 changes paletted images to RGB, and adds a full alpha channel if there is
@@ -2293,7 +2301,7 @@ Within the matrix,
      "-" means the transformation is not supported.
      "." means nothing is necessary (a tRNS chunk can just be ignored).
      "t" means the transformation is obtained by png_set_tRNS.
-     "A" means the transformation is obtained by png_set_add_alpha().
+     "A" means the transformation is obtained by png_set_add_alpha_16().
      "X" means the transformation is obtained by png_set_expand().
      "1" means the transformation is obtained by
          png_set_expand_gray_1_2_4_to_8() (and by png_set_expand()
@@ -2356,24 +2364,26 @@ PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
 into 4 or 8 bytes for windowing systems that need them in this format:
 
     if (color_type == PNG_COLOR_TYPE_RGB)
-       png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+       png_set_filler_16(png_ptr, filler, PNG_FILLER_BEFORE);
 
-where "filler" is the 8 or 16-bit number to fill with, and the location is
-either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+where "filler" is the 8-bit or 16-bit number to fill with, and the location
+is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
 you want the filler before the RGB or after.  This transformation
 does not affect images that already have full alpha channels.  To add an
-opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+opaque alpha channel, use filler=0xffff and PNG_FILLER_AFTER which
 will generate RGBA pixels.
 
-Note that png_set_filler() does not change the color type.  If you want
+Note that png_set_filler_16() does not change the color type.  If you want
 to do that, you can add a true alpha channel with
 
     if (color_type == PNG_COLOR_TYPE_RGB ||
        color_type == PNG_COLOR_TYPE_GRAY)
-       png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+       png_set_add_alpha_16(png_ptr, filler, PNG_FILLER_AFTER);
 
 where "filler" contains the alpha value to assign to each pixel.
-This function was added in libpng-1.2.7.
+The png_set_alpha() function was added in libpng-1.2.7 and the
+png_set_alpha_16() function, which can be used for either 8-bit or
+16-bit images, was added in libpng-1.5.24.
 
 If you are reading an image with an alpha channel, and you need the
 data as ARGB instead of the normal PNG format RGBA:
@@ -5412,7 +5422,13 @@ limits are now
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
 The png_set_option() function (and the "options" member of the png struct) was
-added to libpng-1.5.15.
+added to libpng-1.5.15, with option PNG_ARM_NEON.
+
+The png_set_filler_16() and png_set_add_alpha_16() functions were added
+at libpng-1.5.24 and libpng-1.6.19.  These replace the png_set_filler(() and
+the png_set_add_alpha() functions, which did not work properly with 16-bit
+images.  The new functions can be used with either 8-bit or 16-bit images,
+while the old functions are still available for use only with 8-bit images.
 
 The library now supports a complete fixed point implementation and can
 thus be used on systems that have no floating point support or very
@@ -5820,7 +5836,7 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVI. Y2K Compliance in libpng
 
-August 19, 2015
+September 24, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
@@ -6141,7 +6157,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.19beta03 - August 19, 2015:
+Libpng version 1.6.19beta03 - September 24, 2015:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6164,7 +6180,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.6.19beta03, August 19, 2015, are
+libpng versions 1.0.7, July 1, 2000, through 1.6.19beta03, September 24, 2015, are
 Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.0.6
 with the following individuals added to the list of Contributing Authors:
@@ -6258,7 +6274,7 @@ the additional disclaimers inserted at version 1.0.7.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 19, 2015
+September 24, 2015
 
 .\" end of man page
 
diff --git a/png.h b/png.h
index 04638e4de..34fa0254c 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.19beta03, August 19, 2015
+ * libpng version 1.6.19beta03, September 24, 2015
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.19beta03, August 19, 2015: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.19beta03, September 24, 2015: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -251,7 +251,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.0.7, July 1, 2000, through 1.6.19beta03, August 19, 2015, are
+ * libpng versions 1.0.7, July 1, 2000, through 1.6.19beta03, September 24, 2015, are
  * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.0.6
  * with the following individuals added to the list of Contributing Authors:
@@ -360,7 +360,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    August 19, 2015
+ *    September 24, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -430,7 +430,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.19beta03"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.19beta03 - August 19, 2015\n"
+     " libpng version 1.6.19beta03 - September 24, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -1396,12 +1396,18 @@ PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
     int flags));
+/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(245, void, png_set_filler_16, (png_structrp png_ptr,
+    png_uint_32 filler, int flags));
 /* The values of the PNG_FILLER_ defines should NOT be changed */
 #  define PNG_FILLER_BEFORE 0
 #  define PNG_FILLER_AFTER 1
 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
     png_uint_32 filler, int flags));
+/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(246, void, png_set_add_alpha_16, (png_structrp png_ptr,
+    png_uint_32 filler, int flags));
 #endif /* READ_FILLER || WRITE_FILLER */
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
@@ -3264,7 +3270,7 @@ PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
  * one to use is one more than this.)
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(244);
+  PNG_EXPORT_LAST_ORDINAL(246);
 #endif
 
 #ifdef __cplusplus
diff --git a/pngpriv.h b/pngpriv.h
index c466d4bfe..7a549140c 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -599,6 +599,7 @@
 #define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000 /* Added to libpng-1.4.0 */
 #define PNG_FLAG_APP_WARNINGS_WARN      0x200000 /* Added to libpng-1.6.0 */
 #define PNG_FLAG_APP_ERRORS_WARN        0x400000 /* Added to libpng-1.6.0 */
+#define PNG_FLAG_FILLER_16              0x800000 /* old filler byte order */
                                   /*    0x800000    unused */
                                   /*   0x1000000    unused */
                                   /*   0x2000000    unused */
diff --git a/pngread.c b/pngread.c
index 48aae8488..1b1bdbfe5 100644
--- a/pngread.c
+++ b/pngread.c
@@ -3860,7 +3860,7 @@ png_image_read_direct(png_voidp argument)
 #           endif
                where = PNG_FILLER_AFTER;
 
-            png_set_add_alpha(png_ptr, filler, where);
+            png_set_add_alpha_16(png_ptr, filler, where);
          }
 
          /* This stops the (irrelevant) call to swap_alpha below. */
diff --git a/pngrtran.c b/pngrtran.c
index 284226aeb..208f4ceab 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -2660,10 +2660,17 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    png_uint_32 i;
    png_uint_32 row_width = row_info->width;
 
+   png_byte lo_filler = (png_byte)filler;
+
 #ifdef PNG_READ_16BIT_SUPPORTED
    png_byte hi_filler = (png_byte)(filler>>8);
+   if (((flags & PNG_FLAG_FILLER_16) == 0) && row_info->bit_depth == 16)
+   {
+      /* filler bytes were read in the wrong order prior to libpng-1.5.24 */
+      lo_filler = hi_filler;
+      hi_filler = (png_byte)filler;
+   }
 #endif
-   png_byte lo_filler = (png_byte)filler;
 
    png_debug(1, "in png_do_read_filler");
 
diff --git a/pngtrans.c b/pngtrans.c
index 0c0d92d8f..4e184067d 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -119,7 +119,17 @@ png_set_interlace_handling(png_structrp png_ptr)
 void PNGAPI
 png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
-   png_debug(1, "in png_set_filler");
+   if (png_ptr == NULL)
+      return;
+   png_set_filler_16(png_ptr, filler, filler_loc);
+   png_ptr->flags &= ~PNG_FLAG_FILLER_16; /* Wrong byte order */
+}
+
+/* Added to libpng-1.5.24 */
+void PNGAPI
+png_set_filler_16(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_filler_16");
 
    if (png_ptr == NULL)
       return;
@@ -139,6 +149,7 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
           * confusion in the past.)  The filler is only used in the read code.
           */
          png_ptr->filler = (png_uint_16)filler;
+         png_ptr->flags |= PNG_FLAG_FILLER_16; /* Correct byte order */
 #     else
          png_app_error(png_ptr, "png_set_filler not supported on read");
          PNG_UNUSED(filler) /* not used in the write case */
@@ -203,12 +214,23 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 void PNGAPI
 png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
+   if (png_ptr == NULL)
+      return;
+
+   png_set_add_alpha_16(png_ptr, filler, filler_loc);
+   png_ptr->flags &= ~PNG_FLAG_FILLER_16; /* Wrong byte order */
+}
+
+/* Added to libpng-1.5.24 */
+void PNGAPI
+png_set_add_alpha_16(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
    png_debug(1, "in png_set_add_alpha");
 
    if (png_ptr == NULL)
       return;
 
-   png_set_filler(png_ptr, filler, filler_loc);
+   png_set_filler_16(png_ptr, filler, filler_loc);
    /* The above may fail to do anything. */
    if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_ptr->transformations |= PNG_ADD_ALPHA;
diff --git a/pngwrite.c b/pngwrite.c
index 2da3f01f3..992f48b77 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1396,11 +1396,11 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
                 "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
 
          /* Continue if ignored - this is the pre-1.6.10 behavior */
-         png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+         png_set_filler_16(png_ptr, 0, PNG_FILLER_AFTER);
       }
 
       else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
-         png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+         png_set_filler_16(png_ptr, 0, PNG_FILLER_BEFORE);
 #else
       png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
 #endif
diff --git a/scripts/symbols.def b/scripts/symbols.def
index d36b59035..f4e90092f 100644
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -249,3 +249,5 @@ EXPORTS
  png_set_check_for_invalid_index @242
  png_get_palette_max @243
  png_set_option @244
+ png_set_filler_16 @245
+ png_set_add_alpha_16 @246