XFA: Upgrade libpng to 1.6.20.

third_party/libpng/pngtrans.c

+
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in 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)
 /* Turn on BGR-to-RGB mapping */
 void PNGAPI
 png_set_bgr(png_structrp png_ptr)
 {
    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)
-/* Turn on 16 bit byte swapping */
+/* Turn on 16-bit byte swapping */
 void PNGAPI
 png_set_swap(png_structrp png_ptr)
 {
    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)
 /* Turn on pixel packing */
 void PNGAPI
 png_set_packing(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packing");
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
-      png_ptr->usr_bit_depth = 8;
+#     ifdef PNG_WRITE_SUPPORTED
+         png_ptr->usr_bit_depth = 8;
+#     endif
    }
 }
 #endif
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 /* Turn on packed pixel swapping */
 void PNGAPI
 png_set_packswap(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packswap");
@@ skipping 20 matching lines @@
 }
 #endif
 
 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
     defined(PNG_WRITE_INTERLACING_SUPPORTED)
 int PNGAPI
 png_set_interlace_handling(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_interlace handling");
 
-   if (png_ptr && png_ptr->interlaced)
+   if (png_ptr != 0 && png_ptr->interlaced != 0)
    {
       png_ptr->transformations |= PNG_INTERLACE;
       return (7);
    }
 
    return (1);
 }
 #endif
 
 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
 /* Add a filler byte on read, or remove a filler or alpha byte on write.
  * The filler type has changed in v0.95 to allow future 2-byte fillers
  * for 48-bit input data, as well as to avoid problems with some compilers
  * that don't like bytes as parameters.
  */
 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;
 
    /* In libpng 1.6 it is possible to determine whether this is a read or write
     * operation and therefore to do more checking here for a valid call.
     */
-   if (png_ptr->mode & PNG_IS_READ_STRUCT)
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
    {
 #     ifdef PNG_READ_FILLER_SUPPORTED
          /* On read png_set_filler is always valid, regardless of the base PNG
           * format, because other transformations can give a format where the
           * filler code can execute (basically an 8 or 16-bit component RGB or G
           * format.)
           *
           * NOTE: usr_channels is not used by the read code!  (This has led to
           * confusion in the past.)  The filler is only used in the read code.
           */
@@ skipping 62 matching lines @@
 void PNGAPI
 png_set_add_alpha(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);
    /* The above may fail to do anything. */
-   if (png_ptr->transformations & PNG_FILLER)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
 #endif
 
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 void PNGAPI
 png_set_swap_alpha(png_structrp png_ptr)
 {
@@ skipping 82 matching lines @@
          *(rp + 1) = (png_byte)(~(*(rp + 1)));
          rp += 4;
       }
    }
 #endif
 }
 #endif
 
 #ifdef PNG_16BIT_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)
 {
    png_debug(1, "in png_do_swap");
 
    if (row_info->bit_depth == 16)
    {
       png_bytep rp = row;
       png_uint_32 i;
       png_uint_32 istop= row_info->width * row_info->channels;
 
       for (i = 0; i < istop; i++, rp += 2)
       {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+         /* Feature added to libpng-1.6.11 for testing purposes, not
+          * enabled by default.
+          */
+         *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
          png_byte t = *rp;
          *rp = *(rp + 1);
          *(rp + 1) = t;
+#endif
       }
    }
 }
 #endif
 #endif
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 static PNG_CONST png_byte onebppswaptable[256] = {
    0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
    0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
@@ skipping 121 matching lines @@
       else if (row_info->bit_depth == 4)
          table = fourbppswaptable;
 
       else
          return;
 
       for (rp = row; rp < end; rp++)
          *rp = table[*rp];
    }
 }
-#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+#endif /* PACKSWAP || WRITE_PACKSWAP */
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
 /* 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.
@@ skipping 11 matching lines @@
     *
     * 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->bit_depth == 8)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* 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;
 
          row_info->pixel_depth = 8;
       }
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* 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 */
+         if (at_start != 0) /* 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->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             sp += 2;
          else          /* Skip initial channels and, for sp, the filler */
             sp += 8, dp += 6;
 
          while (sp < ep)
          {
             /* Copy 6 bytes, skip 2 */
             *dp++ = *sp++, *dp++ = *sp++;
             *dp++ = *sp++, *dp++ = *sp++;
             *dp++ = *sp++, *dp++ = *sp, sp += 3;
@@ skipping 20 matching lines @@
 }
 #endif
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* Swaps red and blue bytes within a pixel */
 void /* PRIVATE */
 png_do_bgr(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_bgr");
 
-   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)
       {
          if (row_info->color_type == PNG_COLOR_TYPE_RGB)
          {
             png_bytep rp;
             png_uint_32 i;
 
             for (i = 0, rp = row; i < row_width; i++, rp += 3)
@@ skipping 49 matching lines @@
                *(rp + 4) = save;
                save = *(rp + 1);
                *(rp + 1) = *(rp + 5);
                *(rp + 5) = save;
             }
          }
       }
 #endif
    }
 }
-#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+#endif /* READ_BGR || WRITE_BGR */
 
 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
 /* Added at libpng-1.5.10 */
 void /* PRIVATE */
 png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
 {
    if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
       png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
    {
       /* Calculations moved outside switch in an attempt to stop different
        * compiler warnings.  'padding' is in *bits* within the last byte, it is
        * an 'int' because pixel_depth becomes an 'int' in the expression below,
        * and this calculation is used because it avoids warnings that other
        * forms produced on either GCC or MSVC.
        */
       int padding = (-row_info->pixel_depth * row_info->width) & 7;
       png_bytep rp = png_ptr->row_buf + row_info->rowbytes;
 
       switch (row_info->bit_depth)
       {
          case 1:
          {
             /* in this case, all bytes must be 0 so we don't need
              * to unpack the pixels except for the rightmost one.
              */
             for (; rp > png_ptr->row_buf; rp--)
             {
-              if (*rp >> padding != 0)
+              if ((*rp >> padding) != 0)
                  png_ptr->num_palette_max = 1;
               padding = 0;
             }
 
             break;
          }
 
          case 2:
          {
             for (; rp > png_ptr->row_buf; rp--)
@@ skipping 53 matching lines @@
             }
 
             break;
          }
 
          default:
             break;
       }
    }
 }
-#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */
+#endif /* CHECK_FOR_INVALID_INDEX */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 void PNGAPI
 png_set_user_transform_info(png_structrp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {
    png_debug(1, "in png_set_user_transform_info");
 
@@ skipping 29 matching lines @@
       return (NULL);
 
    return png_ptr->user_transform_ptr;
 }
 #endif
 
 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
 png_uint_32 PNGAPI
 png_get_current_row_number(png_const_structrp png_ptr)
 {
-   /* See the comments in png.h - this is the sub-image row when reading and
+   /* See the comments in png.h - this is the sub-image row when reading an
     * 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_structrp 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 */
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */