Fixed interface typo breaking wxRibbonBar docs (from r72495).

[wxWidgets.git] / src / png / pngtrans.c

diff --git a/src/png/pngtrans.c b/src/png/pngtrans.c
index d850ee7ac2bcdce6ee53b570f6f564db1fed4bb7..6a6908dcd26892635ec6b1dd31d55ed848f9736c 100644 (file)
--- a/src/png/pngtrans.c
+++ b/src/png/pngtrans.c
@@ -1,43 +1,59 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *

- * libpng 1.2.4 - July 8, 2002
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2002 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.4 [July 7, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson

  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)

+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h

  */
 
  */
 

-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)

-/* turn on BGR-to-RGB mapping */
+/* Turn on BGR-to-RGB mapping */

 void PNGAPI
 png_set_bgr(png_structp png_ptr)
 {
 void PNGAPI
 png_set_bgr(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_bgr\n");
+   png_debug(1, "in png_set_bgr");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_BGR;
 }
 #endif
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
    png_ptr->transformations |= PNG_BGR;
 }
 #endif
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)

-/* turn on 16 bit byte swapping */
+/* Turn on 16 bit byte swapping */

 void PNGAPI
 png_set_swap(png_structp png_ptr)
 {
 void PNGAPI
 png_set_swap(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_swap\n");
+   png_debug(1, "in png_set_swap");
+
+   if (png_ptr == NULL)
+      return;
+

    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

-/* turn on pixel packing */
+/* Turn on pixel packing */

 void PNGAPI
 png_set_packing(png_structp png_ptr)
 {
 void PNGAPI
 png_set_packing(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_packing\n");
+   png_debug(1, "in png_set_packing");
+
+   if (png_ptr == NULL)
+      return;
+

    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;


@@ -47,11 +63,15 @@ png_set_packing(png_structp png_ptr)
 #endif
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 #endif
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)

-/* turn on packed pixel swapping */
+/* Turn on packed pixel swapping */

 void PNGAPI
 png_set_packswap(png_structp png_ptr)
 {
 void PNGAPI
 png_set_packswap(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_packswap\n");
+   png_debug(1, "in png_set_packswap");
+
+   if (png_ptr == NULL)
+      return;
+

    if (png_ptr->bit_depth < 8)
       png_ptr->transformations |= PNG_PACKSWAP;
 }
    if (png_ptr->bit_depth < 8)
       png_ptr->transformations |= PNG_PACKSWAP;
 }


@@ -59,9 +79,13 @@ png_set_packswap(png_structp png_ptr)
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI

-png_set_shift(png_structp png_ptr, png_color_8p true_bits)
+png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)

 {
 {

-   png_debug(1, "in png_set_shift\n");
+   png_debug(1, "in png_set_shift");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }
    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }


@@ -72,8 +96,9 @@ png_set_shift(png_structp png_ptr, png_color_8p true_bits)
 int PNGAPI
 png_set_interlace_handling(png_structp png_ptr)
 {
 int PNGAPI
 png_set_interlace_handling(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_interlace handling\n");
-   if (png_ptr->interlaced)
+   png_debug(1, "in png_set_interlace handling");
+
+   if (png_ptr && png_ptr->interlaced)

    {
       png_ptr->transformations |= PNG_INTERLACE;
       return (7);
    {
       png_ptr->transformations |= PNG_INTERLACE;
       return (7);


@@ -92,15 +117,21 @@ png_set_interlace_handling(png_structp png_ptr)
 void PNGAPI
 png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 {
 void PNGAPI
 png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 {

-   png_debug(1, "in png_set_filler\n");
+   png_debug(1, "in png_set_filler");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_FILLER;
    png_ptr->transformations |= PNG_FILLER;

-   png_ptr->filler = (png_byte)filler;
+   png_ptr->filler = (png_uint_16)filler;
+

    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;

+

    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
 

-   /* This should probably go in the "do_filler" routine.
+   /* This should probably go in the "do_read_filler" routine.

     * I attempted to do that in libpng-1.0.1a but that caused problems
     * so I restored it in libpng-1.0.2a
    */
     * I attempted to do that in libpng-1.0.1a but that caused problems
     * so I restored it in libpng-1.0.2a
    */


@@ -111,13 +142,27 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
    }
 
    /* Also I added this in libpng-1.0.2a (what happens when we expand
    }
 
    /* Also I added this in libpng-1.0.2a (what happens when we expand

-    * a less-than-8-bit grayscale to GA? */
+    * a less-than-8-bit grayscale to GA?) */

 
    if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
    {
       png_ptr->usr_channels = 2;
    }
 }
 
    if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
    {
       png_ptr->usr_channels = 2;
    }
 }

+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structp 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_ptr->transformations |= PNG_ADD_ALPHA;
+}
+

 #endif
 
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
 #endif
 
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \


@@ -125,7 +170,11 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 void PNGAPI
 png_set_swap_alpha(png_structp png_ptr)
 {
 void PNGAPI
 png_set_swap_alpha(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_swap_alpha\n");
+   png_debug(1, "in png_set_swap_alpha");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_SWAP_ALPHA;
 }
 #endif
    png_ptr->transformations |= PNG_SWAP_ALPHA;
 }
 #endif


@@ -135,7 +184,11 @@ png_set_swap_alpha(png_structp png_ptr)
 void PNGAPI
 png_set_invert_alpha(png_structp png_ptr)
 {
 void PNGAPI
 png_set_invert_alpha(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_invert_alpha\n");
+   png_debug(1, "in png_set_invert_alpha");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif
    png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif


@@ -144,27 +197,28 @@ png_set_invert_alpha(png_structp png_ptr)
 void PNGAPI
 png_set_invert_mono(png_structp png_ptr)
 {
 void PNGAPI
 png_set_invert_mono(png_structp png_ptr)
 {

-   png_debug(1, "in png_set_invert_mono\n");
+   png_debug(1, "in png_set_invert_mono");
+
+   if (png_ptr == NULL)
+      return;
+

    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 

-/* invert monochrome grayscale data */
+/* Invert monochrome grayscale data */

 void /* PRIVATE */
 png_do_invert(png_row_infop row_info, png_bytep row)
 {
 void /* PRIVATE */
 png_do_invert(png_row_infop row_info, png_bytep row)
 {

-   png_debug(1, "in png_do_invert\n");
+   png_debug(1, "in png_do_invert");
+

   /* This test removed from libpng version 1.0.13 and 1.2.0:
    *   if (row_info->bit_depth == 1 &&
    */
   /* This test removed from libpng version 1.0.13 and 1.2.0:
    *   if (row_info->bit_depth == 1 &&
    */

-#if defined(PNG_USELESS_TESTS_SUPPORTED)
-   if (row == NULL || row_info == NULL)
-     return;
-#endif

    if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
       png_bytep rp = row;
    if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
       for (i = 0; i < istop; i++)
       {
 
       for (i = 0; i < istop; i++)
       {


@@ -172,47 +226,49 @@ png_do_invert(png_row_infop row_info, png_bytep row)
          rp++;
       }
    }
          rp++;
       }
    }

+

    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 8)
    {
       png_bytep rp = row;
    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 8)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
 

-      for (i = 0; i < istop; i+=2)
+      for (i = 0; i < istop; i += 2)

       {
          *rp = (png_byte)(~(*rp));
       {
          *rp = (png_byte)(~(*rp));

-         rp+=2;
+         rp += 2;

       }
    }
       }
    }

+
+#ifdef PNG_16BIT_SUPPORTED

    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 16)
    {
       png_bytep rp = row;
    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 16)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
 

-      for (i = 0; i < istop; i+=4)
+      for (i = 0; i < istop; i += 4)

       {
          *rp = (png_byte)(~(*rp));
       {
          *rp = (png_byte)(~(*rp));

-         *(rp+1) = (png_byte)(~(*(rp+1)));
-         rp+=4;
+         *(rp + 1) = (png_byte)(~(*(rp + 1)));
+         rp += 4;

       }
    }
       }
    }

+#endif

 }
 #endif
 
 }
 #endif
 

+#ifdef PNG_16BIT_SUPPORTED

 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)

-/* swaps byte order on 16 bit depth images */
+/* Swaps byte order on 16 bit depth images */

 void /* PRIVATE */
 png_do_swap(png_row_infop row_info, png_bytep row)
 {
 void /* PRIVATE */
 png_do_swap(png_row_infop row_info, png_bytep row)
 {

-   png_debug(1, "in png_do_swap\n");
-   if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
-       row != NULL && row_info != NULL &&
-#endif
-       row_info->bit_depth == 16)
+   png_debug(1, "in png_do_swap");
+
+   if (row_info->bit_depth == 16)

    {
       png_bytep rp = row;
       png_uint_32 i;
    {
       png_bytep rp = row;
       png_uint_32 i;


@@ -227,9 +283,10 @@ png_do_swap(png_row_infop row_info, png_bytep row)
    }
 }
 #endif
    }
 }
 #endif

+#endif

 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)

-static png_byte onebppswaptable[256] = {
+static PNG_CONST png_byte onebppswaptable[256] = {

    0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
    0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
    0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
    0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
    0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
    0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,


@@ -264,7 +321,7 @@ static png_byte onebppswaptable[256] = {
    0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
 };
 
    0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
 };
 

-static png_byte twobppswaptable[256] = {
+static PNG_CONST png_byte twobppswaptable[256] = {

    0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
    0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
    0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
    0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
    0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
    0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,


@@ -299,7 +356,7 @@ static png_byte twobppswaptable[256] = {
    0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
 };
 
    0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
 };
 

-static png_byte fourbppswaptable[256] = {
+static PNG_CONST png_byte fourbppswaptable[256] = {

    0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
    0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
    0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
    0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
    0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
    0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,


@@ -334,27 +391,28 @@ static png_byte fourbppswaptable[256] = {
    0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
 };
 
    0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
 };
 

-/* swaps pixel packing order within bytes */
+/* Swaps pixel packing order within bytes */

 void /* PRIVATE */
 png_do_packswap(png_row_infop row_info, png_bytep row)
 {
 void /* PRIVATE */
 png_do_packswap(png_row_infop row_info, png_bytep row)
 {

-   png_debug(1, "in png_do_packswap\n");
-   if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
-       row != NULL && row_info != NULL &&
-#endif
-       row_info->bit_depth < 8)
+   png_debug(1, "in png_do_packswap");
+
+   if (row_info->bit_depth < 8)

    {
    {

-      png_bytep rp, end, table;
+      png_bytep rp;
+      png_const_bytep end, table;

 
       end = row + row_info->rowbytes;
 
       if (row_info->bit_depth == 1)
          table = onebppswaptable;
 
       end = row + row_info->rowbytes;
 
       if (row_info->bit_depth == 1)
          table = onebppswaptable;

+

       else if (row_info->bit_depth == 2)
          table = twobppswaptable;
       else if (row_info->bit_depth == 2)
          table = twobppswaptable;

+

       else if (row_info->bit_depth == 4)
          table = fourbppswaptable;
       else if (row_info->bit_depth == 4)
          table = fourbppswaptable;

+

       else
          return;
 
       else
          return;
 


@@ -366,176 +424,130 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)

-/* remove filler or alpha byte(s) */
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do.  All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */

 void /* PRIVATE */
 void /* PRIVATE */

-png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags)
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)

 {
 {

-   png_debug(1, "in png_do_strip_filler\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
-   if (row != NULL && row_info != NULL)
-#endif
+   png_bytep sp = row; /* source pointer */
+   png_bytep dp = row; /* destination pointer */
+   png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+   /* At the start sp will point to the first byte to copy and dp to where
+    * it is copied to.  ep always points just beyond the end of the row, so
+    * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+    */
+
+   /* GA, GX, XG cases */
+   if (row_info->channels == 2)

    {
    {

-/*
-      if (row_info->color_type == PNG_COLOR_TYPE_RGB ||
-          row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-*/
-      png_bytep sp=row;
-      png_bytep dp=row;
-      png_uint_32 row_width=row_info->width;
-      png_uint_32 i;
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 2, ++dp;
+
+         /* For a 1 pixel wide image there is nothing to do */
+         while (sp < ep)
+            *dp++ = *sp, sp += 2;

 
 

-      if (row_info->channels == 4)
+         row_info->pixel_depth = 8;
+      }
+
+      else if (row_info->bit_depth == 16)

       {
       {

-         if (row_info->bit_depth == 8)
-         {
-            /* This converts from RGBX or RGBA to RGB */
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               dp+=3; sp+=4;
-               for (i = 1; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp++;
-               }
-            }
-            /* This converts from XRGB or ARGB to RGB */
-            else
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 24;
-            row_info->rowbytes = row_width * 3;
-         }
-         else /* if (row_info->bit_depth == 16) */
-         {
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */
-               sp += 8; dp += 6;
-               for (i = 1; i < row_width; i++)
-               {
-                  /* This could be (although png_memcpy is probably slower):
-                  png_memcpy(dp, sp, 6);
-                  sp += 8;
-                  dp += 6;
-                  */
-
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp += 2;
-               }
-            }
-            else
-            {
-               /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */
-               for (i = 0; i < row_width; i++)
-               {
-                  /* This could be (although png_memcpy is probably slower):
-                  png_memcpy(dp, sp, 6);
-                  sp += 8;
-                  dp += 6;
-                  */
-
-                  sp+=2;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 48;
-            row_info->rowbytes = row_width * 6;
-         }
-         row_info->channels = 3;
-         row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 4, dp += 2;
+
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;
+
+         row_info->pixel_depth = 16;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 1;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_GRAY;
+   }
+
+   /* RGBA, RGBX, XRGB cases */
+   else if (row_info->channels == 4)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 4, dp += 3;
+
+         /* Note that the loop adds 3 to dp and 4 to sp each time. */
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
+
+         row_info->pixel_depth = 24;

       }
       }

-/*
-      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY ||
-               row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-*/
-      else if (row_info->channels == 2)
+
+      else if (row_info->bit_depth == 16)

       {
       {

-         if (row_info->bit_depth == 8)
-         {
-            /* This converts from GX or GA to G */
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  sp++;
-               }
-            }
-            /* This converts from XG or AG to G */
-            else
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 8;
-            row_info->rowbytes = row_width;
-         }
-         else /* if (row_info->bit_depth == 16) */
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 8, dp += 6;
+
+         while (sp < ep)

          {
          {

-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               /* This converts from GGXX or GGAA to GG */
-               sp += 4; dp += 2;
-               for (i = 1; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp += 2;
-               }
-            }
-            else
-            {
-               /* This converts from XXGG or AAGG to GG */
-               for (i = 0; i < row_width; i++)
-               {
-                  sp += 2;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 16;
-            row_info->rowbytes = row_width * 2;
+            /* Copy 6 bytes, skip 2 */
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;

          }
          }

-         row_info->channels = 1;
-         row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+
+         row_info->pixel_depth = 48;

       }
       }

+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 3;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_RGB;

    }
    }

+
+   else
+      return; /* The filler channel has gone already */
+
+   /* Fix the rowbytes value. */
+   row_info->rowbytes = dp-row;

 }
 #endif
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 }
 #endif
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)

-/* swaps red and blue bytes within a pixel */
+/* Swaps red and blue bytes within a pixel */

 void /* PRIVATE */
 png_do_bgr(png_row_infop row_info, png_bytep row)
 {
 void /* PRIVATE */
 png_do_bgr(png_row_infop row_info, png_bytep row)
 {

-   png_debug(1, "in png_do_bgr\n");
-   if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
-       row != NULL && row_info != NULL &&
-#endif
-       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   png_debug(1, "in png_do_bgr");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))

    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)
    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)


@@ -552,6 +564,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
                *(rp + 2) = save;
             }
          }
                *(rp + 2) = save;
             }
          }

+

          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;
          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;


@@ -565,6 +578,8 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
             }
          }
       }
             }
          }
       }

+
+#ifdef PNG_16BIT_SUPPORTED

       else if (row_info->bit_depth == 16)
       {
          if (row_info->color_type == PNG_COLOR_TYPE_RGB)
       else if (row_info->bit_depth == 16)
       {
          if (row_info->color_type == PNG_COLOR_TYPE_RGB)


@@ -582,6 +597,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
                *(rp + 5) = save;
             }
          }
                *(rp + 5) = save;
             }
          }

+

          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;
          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;


@@ -598,27 +614,25 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
             }
          }
       }
             }
          }
       }

+#endif

    }
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
    }
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \

-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_LEGACY_SUPPORTED)
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

 void PNGAPI
 png_set_user_transform_info(png_structp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {
 void PNGAPI
 png_set_user_transform_info(png_structp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {

-   png_debug(1, "in png_set_user_transform_info\n");
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+   png_debug(1, "in png_set_user_transform_info");
+
+   if (png_ptr == NULL)
+      return;

    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;

-#else
-   if(user_transform_ptr || user_transform_depth || user_transform_channels)
-      png_warning(png_ptr,
-        "This version of libpng does not support user transform info");
-#endif

 }
 #endif
 
 }
 #endif
 


@@ -627,14 +641,38 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
  * associated with this pointer before png_write_destroy and png_read_destroy
  * are called.
  */
  * associated with this pointer before png_write_destroy and png_read_destroy
  * are called.
  */

+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

 png_voidp PNGAPI
 png_voidp PNGAPI

-png_get_user_transform_ptr(png_structp png_ptr)
+png_get_user_transform_ptr(png_const_structp png_ptr)

 {
 {

-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+   if (png_ptr == NULL)
+      return (NULL);
+

    return ((png_voidp)png_ptr->user_transform_ptr);
    return ((png_voidp)png_ptr->user_transform_ptr);

-#else
-   if(png_ptr)
-     return (NULL);
-   return (NULL);
+}

 #endif
 #endif

+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structp png_ptr)
+{
+   /* See the comments in png.h - this is the sub-image row when reading and
+    * interlaced image.
+    */
+   if (png_ptr != NULL)
+      return png_ptr->row_number;
+
+   return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structp png_ptr)
+{
+   if (png_ptr != NULL)
+      return png_ptr->pass;
+   return 8; /* invalid */

 }
 }

+#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
+#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
+          PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */