1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/libpng/pngrutil.c	Thu Sep 08 06:28:38 2011 +0300
     1.3 @@ -0,0 +1,3234 @@
     1.4 +
     1.5 +/* pngrutil.c - utilities to read a PNG file
     1.6 + *
     1.7 + * Last changed in libpng 1.2.33 [October 31, 2008]
     1.8 + * For conditions of distribution and use, see copyright notice in png.h
     1.9 + * Copyright (c) 1998-2008 Glenn Randers-Pehrson
    1.10 + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
    1.11 + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
    1.12 + *
    1.13 + * This file contains routines that are only called from within
    1.14 + * libpng itself during the course of reading an image.
    1.15 + */
    1.16 +
    1.17 +#define PNG_INTERNAL
    1.18 +#include "png.h"
    1.19 +#if defined(PNG_READ_SUPPORTED)
    1.20 +
    1.21 +#if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
    1.22 +#  define WIN32_WCE_OLD
    1.23 +#endif
    1.24 +
    1.25 +#ifdef PNG_FLOATING_POINT_SUPPORTED
    1.26 +#  if defined(WIN32_WCE_OLD)
    1.27 +/* strtod() function is not supported on WindowsCE */
    1.28 +__inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **endptr)
    1.29 +{
    1.30 +   double result = 0;
    1.31 +   int len;
    1.32 +   wchar_t *str, *end;
    1.33 +
    1.34 +   len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
    1.35 +   str = (wchar_t *)png_malloc(png_ptr, len * png_sizeof(wchar_t));
    1.36 +   if ( NULL != str )
    1.37 +   {
    1.38 +      MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
    1.39 +      result = wcstod(str, &end);
    1.40 +      len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
    1.41 +      *endptr = (char *)nptr + (png_strlen(nptr) - len + 1);
    1.42 +      png_free(png_ptr, str);
    1.43 +   }
    1.44 +   return result;
    1.45 +}
    1.46 +#  else
    1.47 +#    define png_strtod(p,a,b) strtod(a,b)
    1.48 +#  endif
    1.49 +#endif
    1.50 +
    1.51 +png_uint_32 PNGAPI
    1.52 +png_get_uint_31(png_structp png_ptr, png_bytep buf)
    1.53 +{
    1.54 +#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
    1.55 +   png_uint_32 i = png_get_uint_32(buf);
    1.56 +#else
    1.57 +   /* Avoid an extra function call by inlining the result. */
    1.58 +   png_uint_32 i = ((png_uint_32)(*buf) << 24) +
    1.59 +      ((png_uint_32)(*(buf + 1)) << 16) +
    1.60 +      ((png_uint_32)(*(buf + 2)) << 8) +
    1.61 +      (png_uint_32)(*(buf + 3));
    1.62 +#endif
    1.63 +   if (i > PNG_UINT_31_MAX)
    1.64 +     png_error(png_ptr, "PNG unsigned integer out of range.");
    1.65 +   return (i);
    1.66 +}
    1.67 +#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
    1.68 +/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
    1.69 +png_uint_32 PNGAPI
    1.70 +png_get_uint_32(png_bytep buf)
    1.71 +{
    1.72 +   png_uint_32 i = ((png_uint_32)(*buf) << 24) +
    1.73 +      ((png_uint_32)(*(buf + 1)) << 16) +
    1.74 +      ((png_uint_32)(*(buf + 2)) << 8) +
    1.75 +      (png_uint_32)(*(buf + 3));
    1.76 +
    1.77 +   return (i);
    1.78 +}
    1.79 +
    1.80 +/* Grab a signed 32-bit integer from a buffer in big-endian format.  The
    1.81 + * data is stored in the PNG file in two's complement format, and it is
    1.82 + * assumed that the machine format for signed integers is the same. */
    1.83 +png_int_32 PNGAPI
    1.84 +png_get_int_32(png_bytep buf)
    1.85 +{
    1.86 +   png_int_32 i = ((png_int_32)(*buf) << 24) +
    1.87 +      ((png_int_32)(*(buf + 1)) << 16) +
    1.88 +      ((png_int_32)(*(buf + 2)) << 8) +
    1.89 +      (png_int_32)(*(buf + 3));
    1.90 +
    1.91 +   return (i);
    1.92 +}
    1.93 +
    1.94 +/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
    1.95 +png_uint_16 PNGAPI
    1.96 +png_get_uint_16(png_bytep buf)
    1.97 +{
    1.98 +   png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
    1.99 +      (png_uint_16)(*(buf + 1)));
   1.100 +
   1.101 +   return (i);
   1.102 +}
   1.103 +#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
   1.104 +
   1.105 +/* Read the chunk header (length + type name).
   1.106 + * Put the type name into png_ptr->chunk_name, and return the length.
   1.107 + */
   1.108 +png_uint_32 /* PRIVATE */
   1.109 +png_read_chunk_header(png_structp png_ptr)
   1.110 +{
   1.111 +   png_byte buf[8];
   1.112 +   png_uint_32 length;
   1.113 +
   1.114 +   /* read the length and the chunk name */
   1.115 +   png_read_data(png_ptr, buf, 8);
   1.116 +   length = png_get_uint_31(png_ptr, buf);
   1.117 +
   1.118 +   /* put the chunk name into png_ptr->chunk_name */
   1.119 +   png_memcpy(png_ptr->chunk_name, buf + 4, 4);
   1.120 +
   1.121 +   png_debug2(0, "Reading %s chunk, length = %lu\n",
   1.122 +      png_ptr->chunk_name, length);
   1.123 +
   1.124 +   /* reset the crc and run it over the chunk name */
   1.125 +   png_reset_crc(png_ptr);
   1.126 +   png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
   1.127 +
   1.128 +   /* check to see if chunk name is valid */
   1.129 +   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
   1.130 +
   1.131 +   return length;
   1.132 +}
   1.133 +
   1.134 +/* Read data, and (optionally) run it through the CRC. */
   1.135 +void /* PRIVATE */
   1.136 +png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
   1.137 +{
   1.138 +   if (png_ptr == NULL) return;
   1.139 +   png_read_data(png_ptr, buf, length);
   1.140 +   png_calculate_crc(png_ptr, buf, length);
   1.141 +}
   1.142 +
   1.143 +/* Optionally skip data and then check the CRC.  Depending on whether we
   1.144 +   are reading a ancillary or critical chunk, and how the program has set
   1.145 +   things up, we may calculate the CRC on the data and print a message.
   1.146 +   Returns '1' if there was a CRC error, '0' otherwise. */
   1.147 +int /* PRIVATE */
   1.148 +png_crc_finish(png_structp png_ptr, png_uint_32 skip)
   1.149 +{
   1.150 +   png_size_t i;
   1.151 +   png_size_t istop = png_ptr->zbuf_size;
   1.152 +
   1.153 +   for (i = (png_size_t)skip; i > istop; i -= istop)
   1.154 +   {
   1.155 +      png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
   1.156 +   }
   1.157 +   if (i)
   1.158 +   {
   1.159 +      png_crc_read(png_ptr, png_ptr->zbuf, i);
   1.160 +   }
   1.161 +
   1.162 +   if (png_crc_error(png_ptr))
   1.163 +   {
   1.164 +      if (((png_ptr->chunk_name[0] & 0x20) &&                /* Ancillary */
   1.165 +           !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
   1.166 +          (!(png_ptr->chunk_name[0] & 0x20) &&             /* Critical  */
   1.167 +          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
   1.168 +      {
   1.169 +         png_chunk_warning(png_ptr, "CRC error");
   1.170 +      }
   1.171 +      else
   1.172 +      {
   1.173 +         png_chunk_error(png_ptr, "CRC error");
   1.174 +      }
   1.175 +      return (1);
   1.176 +   }
   1.177 +
   1.178 +   return (0);
   1.179 +}
   1.180 +
   1.181 +/* Compare the CRC stored in the PNG file with that calculated by libpng from
   1.182 +   the data it has read thus far. */
   1.183 +int /* PRIVATE */
   1.184 +png_crc_error(png_structp png_ptr)
   1.185 +{
   1.186 +   png_byte crc_bytes[4];
   1.187 +   png_uint_32 crc;
   1.188 +   int need_crc = 1;
   1.189 +
   1.190 +   if (png_ptr->chunk_name[0] & 0x20)                     /* ancillary */
   1.191 +   {
   1.192 +      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
   1.193 +          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
   1.194 +         need_crc = 0;
   1.195 +   }
   1.196 +   else                                                    /* critical */
   1.197 +   {
   1.198 +      if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
   1.199 +         need_crc = 0;
   1.200 +   }
   1.201 +
   1.202 +   png_read_data(png_ptr, crc_bytes, 4);
   1.203 +
   1.204 +   if (need_crc)
   1.205 +   {
   1.206 +      crc = png_get_uint_32(crc_bytes);
   1.207 +      return ((int)(crc != png_ptr->crc));
   1.208 +   }
   1.209 +   else
   1.210 +      return (0);
   1.211 +}
   1.212 +
   1.213 +#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
   1.214 +    defined(PNG_READ_iCCP_SUPPORTED)
   1.215 +/*
   1.216 + * Decompress trailing data in a chunk.  The assumption is that chunkdata
   1.217 + * points at an allocated area holding the contents of a chunk with a
   1.218 + * trailing compressed part.  What we get back is an allocated area
   1.219 + * holding the original prefix part and an uncompressed version of the
   1.220 + * trailing part (the malloc area passed in is freed).
   1.221 + */
   1.222 +void /* PRIVATE */
   1.223 +png_decompress_chunk(png_structp png_ptr, int comp_type,
   1.224 +                              png_size_t chunklength,
   1.225 +                              png_size_t prefix_size, png_size_t *newlength)
   1.226 +{
   1.227 +   static PNG_CONST char msg[] = "Error decoding compressed text";
   1.228 +   png_charp text;
   1.229 +   png_size_t text_size;
   1.230 +
   1.231 +   if (comp_type == PNG_COMPRESSION_TYPE_BASE)
   1.232 +   {
   1.233 +      int ret = Z_OK;
   1.234 +      png_ptr->zstream.next_in = (png_bytep)(png_ptr->chunkdata + prefix_size);
   1.235 +      png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
   1.236 +      png_ptr->zstream.next_out = png_ptr->zbuf;
   1.237 +      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
   1.238 +
   1.239 +      text_size = 0;
   1.240 +      text = NULL;
   1.241 +
   1.242 +      while (png_ptr->zstream.avail_in)
   1.243 +      {
   1.244 +         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
   1.245 +         if (ret != Z_OK && ret != Z_STREAM_END)
   1.246 +         {
   1.247 +            if (png_ptr->zstream.msg != NULL)
   1.248 +               png_warning(png_ptr, png_ptr->zstream.msg);
   1.249 +            else
   1.250 +               png_warning(png_ptr, msg);
   1.251 +            inflateReset(&png_ptr->zstream);
   1.252 +            png_ptr->zstream.avail_in = 0;
   1.253 +
   1.254 +            if (text ==  NULL)
   1.255 +            {
   1.256 +               text_size = prefix_size + png_sizeof(msg) + 1;
   1.257 +               text = (png_charp)png_malloc_warn(png_ptr, text_size);
   1.258 +               if (text ==  NULL)
   1.259 +                 {
   1.260 +                    png_free(png_ptr, png_ptr->chunkdata);
   1.261 +                    png_ptr->chunkdata = NULL;
   1.262 +                    png_error(png_ptr, "Not enough memory to decompress chunk");
   1.263 +                 }
   1.264 +               png_memcpy(text, png_ptr->chunkdata, prefix_size);
   1.265 +            }
   1.266 +
   1.267 +            text[text_size - 1] = 0x00;
   1.268 +
   1.269 +            /* Copy what we can of the error message into the text chunk */
   1.270 +            text_size = (png_size_t)(chunklength -
   1.271 +              (text - png_ptr->chunkdata) - 1);
   1.272 +            if (text_size > png_sizeof(msg))
   1.273 +               text_size = png_sizeof(msg);
   1.274 +            png_memcpy(text + prefix_size, msg, text_size);
   1.275 +            break;
   1.276 +         }
   1.277 +         if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
   1.278 +         {
   1.279 +            if (text == NULL)
   1.280 +            {
   1.281 +               text_size = prefix_size +
   1.282 +                   png_ptr->zbuf_size - png_ptr->zstream.avail_out;
   1.283 +               text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
   1.284 +               if (text ==  NULL)
   1.285 +               {
   1.286 +                  png_free(png_ptr, png_ptr->chunkdata);
   1.287 +                  png_ptr->chunkdata = NULL;
   1.288 +                  png_error(png_ptr,
   1.289 +                    "Not enough memory to decompress chunk.");
   1.290 +               }
   1.291 +               png_memcpy(text + prefix_size, png_ptr->zbuf,
   1.292 +                    text_size - prefix_size);
   1.293 +               png_memcpy(text, png_ptr->chunkdata, prefix_size);
   1.294 +               *(text + text_size) = 0x00;
   1.295 +            }
   1.296 +            else
   1.297 +            {
   1.298 +               png_charp tmp;
   1.299 +
   1.300 +               tmp = text;
   1.301 +               text = (png_charp)png_malloc_warn(png_ptr,
   1.302 +                  (png_uint_32)(text_size +
   1.303 +                  png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
   1.304 +               if (text == NULL)
   1.305 +               {
   1.306 +                  png_free(png_ptr, tmp);
   1.307 +                  png_free(png_ptr, png_ptr->chunkdata);
   1.308 +                  png_ptr->chunkdata = NULL;
   1.309 +                  png_error(png_ptr,
   1.310 +                    "Not enough memory to decompress chunk..");
   1.311 +               }
   1.312 +               png_memcpy(text, tmp, text_size);
   1.313 +               png_free(png_ptr, tmp);
   1.314 +               png_memcpy(text + text_size, png_ptr->zbuf,
   1.315 +                  (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
   1.316 +               text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
   1.317 +               *(text + text_size) = 0x00;
   1.318 +            }
   1.319 +            if (ret == Z_STREAM_END)
   1.320 +               break;
   1.321 +            else
   1.322 +            {
   1.323 +               png_ptr->zstream.next_out = png_ptr->zbuf;
   1.324 +               png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
   1.325 +            }
   1.326 +         }
   1.327 +      }
   1.328 +      if (ret != Z_STREAM_END)
   1.329 +      {
   1.330 +#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
   1.331 +         char umsg[52];
   1.332 +
   1.333 +         if (ret == Z_BUF_ERROR)
   1.334 +            png_snprintf(umsg, 52,
   1.335 +                "Buffer error in compressed datastream in %s chunk",
   1.336 +                png_ptr->chunk_name);
   1.337 +         else if (ret == Z_DATA_ERROR)
   1.338 +            png_snprintf(umsg, 52,
   1.339 +                "Data error in compressed datastream in %s chunk",
   1.340 +                png_ptr->chunk_name);
   1.341 +         else
   1.342 +            png_snprintf(umsg, 52,
   1.343 +                "Incomplete compressed datastream in %s chunk",
   1.344 +                png_ptr->chunk_name);
   1.345 +         png_warning(png_ptr, umsg);
   1.346 +#else
   1.347 +         png_warning(png_ptr,
   1.348 +            "Incomplete compressed datastream in chunk other than IDAT");
   1.349 +#endif
   1.350 +         text_size = prefix_size;
   1.351 +         if (text ==  NULL)
   1.352 +         {
   1.353 +            text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
   1.354 +            if (text == NULL)
   1.355 +              {
   1.356 +                png_free(png_ptr, png_ptr->chunkdata);
   1.357 +                png_ptr->chunkdata = NULL;
   1.358 +                png_error(png_ptr, "Not enough memory for text.");
   1.359 +              }
   1.360 +            png_memcpy(text, png_ptr->chunkdata, prefix_size);
   1.361 +         }
   1.362 +         *(text + text_size) = 0x00;
   1.363 +      }
   1.364 +
   1.365 +      inflateReset(&png_ptr->zstream);
   1.366 +      png_ptr->zstream.avail_in = 0;
   1.367 +
   1.368 +      png_free(png_ptr, png_ptr->chunkdata);
   1.369 +      png_ptr->chunkdata = text;
   1.370 +      *newlength=text_size;
   1.371 +   }
   1.372 +   else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
   1.373 +   {
   1.374 +#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
   1.375 +      char umsg[50];
   1.376 +
   1.377 +      png_snprintf(umsg, 50, "Unknown zTXt compression type %d", comp_type);
   1.378 +      png_warning(png_ptr, umsg);
   1.379 +#else
   1.380 +      png_warning(png_ptr, "Unknown zTXt compression type");
   1.381 +#endif
   1.382 +
   1.383 +      *(png_ptr->chunkdata + prefix_size) = 0x00;
   1.384 +      *newlength = prefix_size;
   1.385 +   }
   1.386 +}
   1.387 +#endif
   1.388 +
   1.389 +/* read and check the IDHR chunk */
   1.390 +void /* PRIVATE */
   1.391 +png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.392 +{
   1.393 +   png_byte buf[13];
   1.394 +   png_uint_32 width, height;
   1.395 +   int bit_depth, color_type, compression_type, filter_type;
   1.396 +   int interlace_type;
   1.397 +
   1.398 +   png_debug(1, "in png_handle_IHDR\n");
   1.399 +
   1.400 +   if (png_ptr->mode & PNG_HAVE_IHDR)
   1.401 +      png_error(png_ptr, "Out of place IHDR");
   1.402 +
   1.403 +   /* check the length */
   1.404 +   if (length != 13)
   1.405 +      png_error(png_ptr, "Invalid IHDR chunk");
   1.406 +
   1.407 +   png_ptr->mode |= PNG_HAVE_IHDR;
   1.408 +
   1.409 +   png_crc_read(png_ptr, buf, 13);
   1.410 +   png_crc_finish(png_ptr, 0);
   1.411 +
   1.412 +   width = png_get_uint_31(png_ptr, buf);
   1.413 +   height = png_get_uint_31(png_ptr, buf + 4);
   1.414 +   bit_depth = buf[8];
   1.415 +   color_type = buf[9];
   1.416 +   compression_type = buf[10];
   1.417 +   filter_type = buf[11];
   1.418 +   interlace_type = buf[12];
   1.419 +
   1.420 +   /* set internal variables */
   1.421 +   png_ptr->width = width;
   1.422 +   png_ptr->height = height;
   1.423 +   png_ptr->bit_depth = (png_byte)bit_depth;
   1.424 +   png_ptr->interlaced = (png_byte)interlace_type;
   1.425 +   png_ptr->color_type = (png_byte)color_type;
   1.426 +#if defined(PNG_MNG_FEATURES_SUPPORTED)
   1.427 +   png_ptr->filter_type = (png_byte)filter_type;
   1.428 +#endif
   1.429 +   png_ptr->compression_type = (png_byte)compression_type;
   1.430 +
   1.431 +   /* find number of channels */
   1.432 +   switch (png_ptr->color_type)
   1.433 +   {
   1.434 +      case PNG_COLOR_TYPE_GRAY:
   1.435 +      case PNG_COLOR_TYPE_PALETTE:
   1.436 +         png_ptr->channels = 1;
   1.437 +         break;
   1.438 +      case PNG_COLOR_TYPE_RGB:
   1.439 +         png_ptr->channels = 3;
   1.440 +         break;
   1.441 +      case PNG_COLOR_TYPE_GRAY_ALPHA:
   1.442 +         png_ptr->channels = 2;
   1.443 +         break;
   1.444 +      case PNG_COLOR_TYPE_RGB_ALPHA:
   1.445 +         png_ptr->channels = 4;
   1.446 +         break;
   1.447 +   }
   1.448 +
   1.449 +   /* set up other useful info */
   1.450 +   png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
   1.451 +   png_ptr->channels);
   1.452 +   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
   1.453 +   png_debug1(3, "bit_depth = %d\n", png_ptr->bit_depth);
   1.454 +   png_debug1(3, "channels = %d\n", png_ptr->channels);
   1.455 +   png_debug1(3, "rowbytes = %lu\n", png_ptr->rowbytes);
   1.456 +   png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
   1.457 +      color_type, interlace_type, compression_type, filter_type);
   1.458 +}
   1.459 +
   1.460 +/* read and check the palette */
   1.461 +void /* PRIVATE */
   1.462 +png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.463 +{
   1.464 +   png_color palette[PNG_MAX_PALETTE_LENGTH];
   1.465 +   int num, i;
   1.466 +#ifndef PNG_NO_POINTER_INDEXING
   1.467 +   png_colorp pal_ptr;
   1.468 +#endif
   1.469 +
   1.470 +   png_debug(1, "in png_handle_PLTE\n");
   1.471 +
   1.472 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
   1.473 +      png_error(png_ptr, "Missing IHDR before PLTE");
   1.474 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
   1.475 +   {
   1.476 +      png_warning(png_ptr, "Invalid PLTE after IDAT");
   1.477 +      png_crc_finish(png_ptr, length);
   1.478 +      return;
   1.479 +   }
   1.480 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
   1.481 +      png_error(png_ptr, "Duplicate PLTE chunk");
   1.482 +
   1.483 +   png_ptr->mode |= PNG_HAVE_PLTE;
   1.484 +
   1.485 +   if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
   1.486 +   {
   1.487 +      png_warning(png_ptr,
   1.488 +        "Ignoring PLTE chunk in grayscale PNG");
   1.489 +      png_crc_finish(png_ptr, length);
   1.490 +      return;
   1.491 +   }
   1.492 +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
   1.493 +   if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
   1.494 +   {
   1.495 +      png_crc_finish(png_ptr, length);
   1.496 +      return;
   1.497 +   }
   1.498 +#endif
   1.499 +
   1.500 +   if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
   1.501 +   {
   1.502 +      if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
   1.503 +      {
   1.504 +         png_warning(png_ptr, "Invalid palette chunk");
   1.505 +         png_crc_finish(png_ptr, length);
   1.506 +         return;
   1.507 +      }
   1.508 +      else
   1.509 +      {
   1.510 +         png_error(png_ptr, "Invalid palette chunk");
   1.511 +      }
   1.512 +   }
   1.513 +
   1.514 +   num = (int)length / 3;
   1.515 +
   1.516 +#ifndef PNG_NO_POINTER_INDEXING
   1.517 +   for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
   1.518 +   {
   1.519 +      png_byte buf[3];
   1.520 +
   1.521 +      png_crc_read(png_ptr, buf, 3);
   1.522 +      pal_ptr->red = buf[0];
   1.523 +      pal_ptr->green = buf[1];
   1.524 +      pal_ptr->blue = buf[2];
   1.525 +   }
   1.526 +#else
   1.527 +   for (i = 0; i < num; i++)
   1.528 +   {
   1.529 +      png_byte buf[3];
   1.530 +
   1.531 +      png_crc_read(png_ptr, buf, 3);
   1.532 +      /* don't depend upon png_color being any order */
   1.533 +      palette[i].red = buf[0];
   1.534 +      palette[i].green = buf[1];
   1.535 +      palette[i].blue = buf[2];
   1.536 +   }
   1.537 +#endif
   1.538 +
   1.539 +   /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
   1.540 +      whatever the normal CRC configuration tells us.  However, if we
   1.541 +      have an RGB image, the PLTE can be considered ancillary, so
   1.542 +      we will act as though it is. */
   1.543 +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
   1.544 +   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
   1.545 +#endif
   1.546 +   {
   1.547 +      png_crc_finish(png_ptr, 0);
   1.548 +   }
   1.549 +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
   1.550 +   else if (png_crc_error(png_ptr))  /* Only if we have a CRC error */
   1.551 +   {
   1.552 +      /* If we don't want to use the data from an ancillary chunk,
   1.553 +         we have two options: an error abort, or a warning and we
   1.554 +         ignore the data in this chunk (which should be OK, since
   1.555 +         it's considered ancillary for a RGB or RGBA image). */
   1.556 +      if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
   1.557 +      {
   1.558 +         if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
   1.559 +         {
   1.560 +            png_chunk_error(png_ptr, "CRC error");
   1.561 +         }
   1.562 +         else
   1.563 +         {
   1.564 +            png_chunk_warning(png_ptr, "CRC error");
   1.565 +            return;
   1.566 +         }
   1.567 +      }
   1.568 +      /* Otherwise, we (optionally) emit a warning and use the chunk. */
   1.569 +      else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
   1.570 +      {
   1.571 +         png_chunk_warning(png_ptr, "CRC error");
   1.572 +      }
   1.573 +   }
   1.574 +#endif
   1.575 +
   1.576 +   png_set_PLTE(png_ptr, info_ptr, palette, num);
   1.577 +
   1.578 +#if defined(PNG_READ_tRNS_SUPPORTED)
   1.579 +   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
   1.580 +   {
   1.581 +      if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
   1.582 +      {
   1.583 +         if (png_ptr->num_trans > (png_uint_16)num)
   1.584 +         {
   1.585 +            png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
   1.586 +            png_ptr->num_trans = (png_uint_16)num;
   1.587 +         }
   1.588 +         if (info_ptr->num_trans > (png_uint_16)num)
   1.589 +         {
   1.590 +            png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
   1.591 +            info_ptr->num_trans = (png_uint_16)num;
   1.592 +         }
   1.593 +      }
   1.594 +   }
   1.595 +#endif
   1.596 +
   1.597 +}
   1.598 +
   1.599 +void /* PRIVATE */
   1.600 +png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.601 +{
   1.602 +   png_debug(1, "in png_handle_IEND\n");
   1.603 +
   1.604 +   if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
   1.605 +   {
   1.606 +      png_error(png_ptr, "No image in file");
   1.607 +   }
   1.608 +
   1.609 +   png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
   1.610 +
   1.611 +   if (length != 0)
   1.612 +   {
   1.613 +      png_warning(png_ptr, "Incorrect IEND chunk length");
   1.614 +   }
   1.615 +   png_crc_finish(png_ptr, length);
   1.616 +
   1.617 +   info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
   1.618 +}
   1.619 +
   1.620 +#if defined(PNG_READ_gAMA_SUPPORTED)
   1.621 +void /* PRIVATE */
   1.622 +png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.623 +{
   1.624 +   png_fixed_point igamma;
   1.625 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.626 +   float file_gamma;
   1.627 +#endif
   1.628 +   png_byte buf[4];
   1.629 +
   1.630 +   png_debug(1, "in png_handle_gAMA\n");
   1.631 +
   1.632 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
   1.633 +      png_error(png_ptr, "Missing IHDR before gAMA");
   1.634 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
   1.635 +   {
   1.636 +      png_warning(png_ptr, "Invalid gAMA after IDAT");
   1.637 +      png_crc_finish(png_ptr, length);
   1.638 +      return;
   1.639 +   }
   1.640 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
   1.641 +      /* Should be an error, but we can cope with it */
   1.642 +      png_warning(png_ptr, "Out of place gAMA chunk");
   1.643 +
   1.644 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
   1.645 +#if defined(PNG_READ_sRGB_SUPPORTED)
   1.646 +      && !(info_ptr->valid & PNG_INFO_sRGB)
   1.647 +#endif
   1.648 +      )
   1.649 +   {
   1.650 +      png_warning(png_ptr, "Duplicate gAMA chunk");
   1.651 +      png_crc_finish(png_ptr, length);
   1.652 +      return;
   1.653 +   }
   1.654 +
   1.655 +   if (length != 4)
   1.656 +   {
   1.657 +      png_warning(png_ptr, "Incorrect gAMA chunk length");
   1.658 +      png_crc_finish(png_ptr, length);
   1.659 +      return;
   1.660 +   }
   1.661 +
   1.662 +   png_crc_read(png_ptr, buf, 4);
   1.663 +   if (png_crc_finish(png_ptr, 0))
   1.664 +      return;
   1.665 +
   1.666 +   igamma = (png_fixed_point)png_get_uint_32(buf);
   1.667 +   /* check for zero gamma */
   1.668 +   if (igamma == 0)
   1.669 +      {
   1.670 +         png_warning(png_ptr,
   1.671 +           "Ignoring gAMA chunk with gamma=0");
   1.672 +         return;
   1.673 +      }
   1.674 +
   1.675 +#if defined(PNG_READ_sRGB_SUPPORTED)
   1.676 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
   1.677 +      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
   1.678 +      {
   1.679 +         png_warning(png_ptr,
   1.680 +           "Ignoring incorrect gAMA value when sRGB is also present");
   1.681 +#ifndef PNG_NO_CONSOLE_IO
   1.682 +         fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma);
   1.683 +#endif
   1.684 +         return;
   1.685 +      }
   1.686 +#endif /* PNG_READ_sRGB_SUPPORTED */
   1.687 +
   1.688 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.689 +   file_gamma = (float)igamma / (float)100000.0;
   1.690 +#  ifdef PNG_READ_GAMMA_SUPPORTED
   1.691 +     png_ptr->gamma = file_gamma;
   1.692 +#  endif
   1.693 +     png_set_gAMA(png_ptr, info_ptr, file_gamma);
   1.694 +#endif
   1.695 +#ifdef PNG_FIXED_POINT_SUPPORTED
   1.696 +   png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
   1.697 +#endif
   1.698 +}
   1.699 +#endif
   1.700 +
   1.701 +#if defined(PNG_READ_sBIT_SUPPORTED)
   1.702 +void /* PRIVATE */
   1.703 +png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.704 +{
   1.705 +   png_size_t truelen;
   1.706 +   png_byte buf[4];
   1.707 +
   1.708 +   png_debug(1, "in png_handle_sBIT\n");
   1.709 +
   1.710 +   buf[0] = buf[1] = buf[2] = buf[3] = 0;
   1.711 +
   1.712 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
   1.713 +      png_error(png_ptr, "Missing IHDR before sBIT");
   1.714 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
   1.715 +   {
   1.716 +      png_warning(png_ptr, "Invalid sBIT after IDAT");
   1.717 +      png_crc_finish(png_ptr, length);
   1.718 +      return;
   1.719 +   }
   1.720 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
   1.721 +   {
   1.722 +      /* Should be an error, but we can cope with it */
   1.723 +      png_warning(png_ptr, "Out of place sBIT chunk");
   1.724 +   }
   1.725 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
   1.726 +   {
   1.727 +      png_warning(png_ptr, "Duplicate sBIT chunk");
   1.728 +      png_crc_finish(png_ptr, length);
   1.729 +      return;
   1.730 +   }
   1.731 +
   1.732 +   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
   1.733 +      truelen = 3;
   1.734 +   else
   1.735 +      truelen = (png_size_t)png_ptr->channels;
   1.736 +
   1.737 +   if (length != truelen || length > 4)
   1.738 +   {
   1.739 +      png_warning(png_ptr, "Incorrect sBIT chunk length");
   1.740 +      png_crc_finish(png_ptr, length);
   1.741 +      return;
   1.742 +   }
   1.743 +
   1.744 +   png_crc_read(png_ptr, buf, truelen);
   1.745 +   if (png_crc_finish(png_ptr, 0))
   1.746 +      return;
   1.747 +
   1.748 +   if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
   1.749 +   {
   1.750 +      png_ptr->sig_bit.red = buf[0];
   1.751 +      png_ptr->sig_bit.green = buf[1];
   1.752 +      png_ptr->sig_bit.blue = buf[2];
   1.753 +      png_ptr->sig_bit.alpha = buf[3];
   1.754 +   }
   1.755 +   else
   1.756 +   {
   1.757 +      png_ptr->sig_bit.gray = buf[0];
   1.758 +      png_ptr->sig_bit.red = buf[0];
   1.759 +      png_ptr->sig_bit.green = buf[0];
   1.760 +      png_ptr->sig_bit.blue = buf[0];
   1.761 +      png_ptr->sig_bit.alpha = buf[1];
   1.762 +   }
   1.763 +   png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
   1.764 +}
   1.765 +#endif
   1.766 +
   1.767 +#if defined(PNG_READ_cHRM_SUPPORTED)
   1.768 +void /* PRIVATE */
   1.769 +png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.770 +{
   1.771 +   png_byte buf[32];
   1.772 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.773 +   float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
   1.774 +#endif
   1.775 +   png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
   1.776 +      int_y_green, int_x_blue, int_y_blue;
   1.777 +
   1.778 +   png_uint_32 uint_x, uint_y;
   1.779 +
   1.780 +   png_debug(1, "in png_handle_cHRM\n");
   1.781 +
   1.782 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
   1.783 +      png_error(png_ptr, "Missing IHDR before cHRM");
   1.784 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
   1.785 +   {
   1.786 +      png_warning(png_ptr, "Invalid cHRM after IDAT");
   1.787 +      png_crc_finish(png_ptr, length);
   1.788 +      return;
   1.789 +   }
   1.790 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
   1.791 +      /* Should be an error, but we can cope with it */
   1.792 +      png_warning(png_ptr, "Missing PLTE before cHRM");
   1.793 +
   1.794 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
   1.795 +#if defined(PNG_READ_sRGB_SUPPORTED)
   1.796 +      && !(info_ptr->valid & PNG_INFO_sRGB)
   1.797 +#endif
   1.798 +      )
   1.799 +   {
   1.800 +      png_warning(png_ptr, "Duplicate cHRM chunk");
   1.801 +      png_crc_finish(png_ptr, length);
   1.802 +      return;
   1.803 +   }
   1.804 +
   1.805 +   if (length != 32)
   1.806 +   {
   1.807 +      png_warning(png_ptr, "Incorrect cHRM chunk length");
   1.808 +      png_crc_finish(png_ptr, length);
   1.809 +      return;
   1.810 +   }
   1.811 +
   1.812 +   png_crc_read(png_ptr, buf, 32);
   1.813 +   if (png_crc_finish(png_ptr, 0))
   1.814 +      return;
   1.815 +
   1.816 +   uint_x = png_get_uint_32(buf);
   1.817 +   uint_y = png_get_uint_32(buf + 4);
   1.818 +   if (uint_x > 80000L || uint_y > 80000L ||
   1.819 +      uint_x + uint_y > 100000L)
   1.820 +   {
   1.821 +      png_warning(png_ptr, "Invalid cHRM white point");
   1.822 +      return;
   1.823 +   }
   1.824 +   int_x_white = (png_fixed_point)uint_x;
   1.825 +   int_y_white = (png_fixed_point)uint_y;
   1.826 +
   1.827 +   uint_x = png_get_uint_32(buf + 8);
   1.828 +   uint_y = png_get_uint_32(buf + 12);
   1.829 +   if (uint_x + uint_y > 100000L)
   1.830 +   {
   1.831 +      png_warning(png_ptr, "Invalid cHRM red point");
   1.832 +      return;
   1.833 +   }
   1.834 +   int_x_red = (png_fixed_point)uint_x;
   1.835 +   int_y_red = (png_fixed_point)uint_y;
   1.836 +
   1.837 +   uint_x = png_get_uint_32(buf + 16);
   1.838 +   uint_y = png_get_uint_32(buf + 20);
   1.839 +   if (uint_x + uint_y > 100000L)
   1.840 +   {
   1.841 +      png_warning(png_ptr, "Invalid cHRM green point");
   1.842 +      return;
   1.843 +   }
   1.844 +   int_x_green = (png_fixed_point)uint_x;
   1.845 +   int_y_green = (png_fixed_point)uint_y;
   1.846 +
   1.847 +   uint_x = png_get_uint_32(buf + 24);
   1.848 +   uint_y = png_get_uint_32(buf + 28);
   1.849 +   if (uint_x + uint_y > 100000L)
   1.850 +   {
   1.851 +      png_warning(png_ptr, "Invalid cHRM blue point");
   1.852 +      return;
   1.853 +   }
   1.854 +   int_x_blue = (png_fixed_point)uint_x;
   1.855 +   int_y_blue = (png_fixed_point)uint_y;
   1.856 +
   1.857 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.858 +   white_x = (float)int_x_white / (float)100000.0;
   1.859 +   white_y = (float)int_y_white / (float)100000.0;
   1.860 +   red_x   = (float)int_x_red   / (float)100000.0;
   1.861 +   red_y   = (float)int_y_red   / (float)100000.0;
   1.862 +   green_x = (float)int_x_green / (float)100000.0;
   1.863 +   green_y = (float)int_y_green / (float)100000.0;
   1.864 +   blue_x  = (float)int_x_blue  / (float)100000.0;
   1.865 +   blue_y  = (float)int_y_blue  / (float)100000.0;
   1.866 +#endif
   1.867 +
   1.868 +#if defined(PNG_READ_sRGB_SUPPORTED)
   1.869 +   if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
   1.870 +      {
   1.871 +      if (PNG_OUT_OF_RANGE(int_x_white, 31270,  1000) ||
   1.872 +          PNG_OUT_OF_RANGE(int_y_white, 32900,  1000) ||
   1.873 +          PNG_OUT_OF_RANGE(int_x_red,   64000L, 1000) ||
   1.874 +          PNG_OUT_OF_RANGE(int_y_red,   33000,  1000) ||
   1.875 +          PNG_OUT_OF_RANGE(int_x_green, 30000,  1000) ||
   1.876 +          PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
   1.877 +          PNG_OUT_OF_RANGE(int_x_blue,  15000,  1000) ||
   1.878 +          PNG_OUT_OF_RANGE(int_y_blue,   6000,  1000))
   1.879 +         {
   1.880 +            png_warning(png_ptr,
   1.881 +              "Ignoring incorrect cHRM value when sRGB is also present");
   1.882 +#ifndef PNG_NO_CONSOLE_IO
   1.883 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.884 +            fprintf(stderr, "wx=%f, wy=%f, rx=%f, ry=%f\n",
   1.885 +               white_x, white_y, red_x, red_y);
   1.886 +            fprintf(stderr, "gx=%f, gy=%f, bx=%f, by=%f\n",
   1.887 +               green_x, green_y, blue_x, blue_y);
   1.888 +#else
   1.889 +            fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
   1.890 +               int_x_white, int_y_white, int_x_red, int_y_red);
   1.891 +            fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
   1.892 +               int_x_green, int_y_green, int_x_blue, int_y_blue);
   1.893 +#endif
   1.894 +#endif /* PNG_NO_CONSOLE_IO */
   1.895 +         }
   1.896 +         return;
   1.897 +      }
   1.898 +#endif /* PNG_READ_sRGB_SUPPORTED */
   1.899 +
   1.900 +#ifdef PNG_FLOATING_POINT_SUPPORTED
   1.901 +   png_set_cHRM(png_ptr, info_ptr,
   1.902 +      white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
   1.903 +#endif
   1.904 +#ifdef PNG_FIXED_POINT_SUPPORTED
   1.905 +   png_set_cHRM_fixed(png_ptr, info_ptr,
   1.906 +      int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
   1.907 +      int_y_green, int_x_blue, int_y_blue);
   1.908 +#endif
   1.909 +}
   1.910 +#endif
   1.911 +
   1.912 +#if defined(PNG_READ_sRGB_SUPPORTED)
   1.913 +void /* PRIVATE */
   1.914 +png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
   1.915 +{
   1.916 +   int intent;
   1.917 +   png_byte buf[1];
   1.918 +
   1.919 +   png_debug(1, "in png_handle_sRGB\n");
   1.920 +
   1.921 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
   1.922 +      png_error(png_ptr, "Missing IHDR before sRGB");
   1.923 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
   1.924 +   {
   1.925 +      png_warning(png_ptr, "Invalid sRGB after IDAT");
   1.926 +      png_crc_finish(png_ptr, length);
   1.927 +      return;
   1.928 +   }
   1.929 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
   1.930 +      /* Should be an error, but we can cope with it */
   1.931 +      png_warning(png_ptr, "Out of place sRGB chunk");
   1.932 +
   1.933 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
   1.934 +   {
   1.935 +      png_warning(png_ptr, "Duplicate sRGB chunk");
   1.936 +      png_crc_finish(png_ptr, length);
   1.937 +      return;
   1.938 +   }
   1.939 +
   1.940 +   if (length != 1)
   1.941 +   {
   1.942 +      png_warning(png_ptr, "Incorrect sRGB chunk length");
   1.943 +      png_crc_finish(png_ptr, length);
   1.944 +      return;
   1.945 +   }
   1.946 +
   1.947 +   png_crc_read(png_ptr, buf, 1);
   1.948 +   if (png_crc_finish(png_ptr, 0))
   1.949 +      return;
   1.950 +
   1.951 +   intent = buf[0];
   1.952 +   /* check for bad intent */
   1.953 +   if (intent >= PNG_sRGB_INTENT_LAST)
   1.954 +   {
   1.955 +      png_warning(png_ptr, "Unknown sRGB intent");
   1.956 +      return;
   1.957 +   }
   1.958 +
   1.959 +#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
   1.960 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
   1.961 +   {
   1.962 +   png_fixed_point igamma;
   1.963 +#ifdef PNG_FIXED_POINT_SUPPORTED
   1.964 +      igamma=info_ptr->int_gamma;
   1.965 +#else
   1.966 +#  ifdef PNG_FLOATING_POINT_SUPPORTED
   1.967 +      igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
   1.968 +#  endif
   1.969 +#endif
   1.970 +      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
   1.971 +      {
   1.972 +         png_warning(png_ptr,
   1.973 +           "Ignoring incorrect gAMA value when sRGB is also present");
   1.974 +#ifndef PNG_NO_CONSOLE_IO
   1.975 +#  ifdef PNG_FIXED_POINT_SUPPORTED
   1.976 +         fprintf(stderr, "incorrect gamma=(%d/100000)\n",
   1.977 +            (int)png_ptr->int_gamma);
   1.978 +#  else
   1.979 +#    ifdef PNG_FLOATING_POINT_SUPPORTED
   1.980 +         fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
   1.981 +#    endif
   1.982 +#  endif
   1.983 +#endif
   1.984 +      }
   1.985 +   }
   1.986 +#endif /* PNG_READ_gAMA_SUPPORTED */
   1.987 +
   1.988 +#ifdef PNG_READ_cHRM_SUPPORTED
   1.989 +#ifdef PNG_FIXED_POINT_SUPPORTED
   1.990 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
   1.991 +      if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270,  1000) ||
   1.992 +          PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900,  1000) ||
   1.993 +          PNG_OUT_OF_RANGE(info_ptr->int_x_red,   64000L, 1000) ||
   1.994 +          PNG_OUT_OF_RANGE(info_ptr->int_y_red,   33000,  1000) ||
   1.995 +          PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000,  1000) ||
   1.996 +          PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
   1.997 +          PNG_OUT_OF_RANGE(info_ptr->int_x_blue,  15000,  1000) ||
   1.998 +          PNG_OUT_OF_RANGE(info_ptr->int_y_blue,   6000,  1000))
   1.999 +         {
  1.1000 +            png_warning(png_ptr,
  1.1001 +              "Ignoring incorrect cHRM value when sRGB is also present");
  1.1002 +         }
  1.1003 +#endif /* PNG_FIXED_POINT_SUPPORTED */
  1.1004 +#endif /* PNG_READ_cHRM_SUPPORTED */
  1.1005 +
  1.1006 +   png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
  1.1007 +}
  1.1008 +#endif /* PNG_READ_sRGB_SUPPORTED */
  1.1009 +
  1.1010 +#if defined(PNG_READ_iCCP_SUPPORTED)
  1.1011 +void /* PRIVATE */
  1.1012 +png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1013 +/* Note: this does not properly handle chunks that are > 64K under DOS */
  1.1014 +{
  1.1015 +   png_byte compression_type;
  1.1016 +   png_bytep pC;
  1.1017 +   png_charp profile;
  1.1018 +   png_uint_32 skip = 0;
  1.1019 +   png_uint_32 profile_size, profile_length;
  1.1020 +   png_size_t slength, prefix_length, data_length;
  1.1021 +
  1.1022 +   png_debug(1, "in png_handle_iCCP\n");
  1.1023 +
  1.1024 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1025 +      png_error(png_ptr, "Missing IHDR before iCCP");
  1.1026 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1027 +   {
  1.1028 +      png_warning(png_ptr, "Invalid iCCP after IDAT");
  1.1029 +      png_crc_finish(png_ptr, length);
  1.1030 +      return;
  1.1031 +   }
  1.1032 +   else if (png_ptr->mode & PNG_HAVE_PLTE)
  1.1033 +      /* Should be an error, but we can cope with it */
  1.1034 +      png_warning(png_ptr, "Out of place iCCP chunk");
  1.1035 +
  1.1036 +   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
  1.1037 +   {
  1.1038 +      png_warning(png_ptr, "Duplicate iCCP chunk");
  1.1039 +      png_crc_finish(png_ptr, length);
  1.1040 +      return;
  1.1041 +   }
  1.1042 +
  1.1043 +#ifdef PNG_MAX_MALLOC_64K
  1.1044 +   if (length > (png_uint_32)65535L)
  1.1045 +   {
  1.1046 +      png_warning(png_ptr, "iCCP chunk too large to fit in memory");
  1.1047 +      skip = length - (png_uint_32)65535L;
  1.1048 +      length = (png_uint_32)65535L;
  1.1049 +   }
  1.1050 +#endif
  1.1051 +
  1.1052 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1053 +   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
  1.1054 +   slength = (png_size_t)length;
  1.1055 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.1056 +
  1.1057 +   if (png_crc_finish(png_ptr, skip))
  1.1058 +   {
  1.1059 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1060 +      png_ptr->chunkdata = NULL;
  1.1061 +      return;
  1.1062 +   }
  1.1063 +
  1.1064 +   png_ptr->chunkdata[slength] = 0x00;
  1.1065 +
  1.1066 +   for (profile = png_ptr->chunkdata; *profile; profile++)
  1.1067 +      /* empty loop to find end of name */ ;
  1.1068 +
  1.1069 +   ++profile;
  1.1070 +
  1.1071 +   /* there should be at least one zero (the compression type byte)
  1.1072 +      following the separator, and we should be on it  */
  1.1073 +   if ( profile >= png_ptr->chunkdata + slength - 1)
  1.1074 +   {
  1.1075 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1076 +      png_ptr->chunkdata = NULL;
  1.1077 +      png_warning(png_ptr, "Malformed iCCP chunk");
  1.1078 +      return;
  1.1079 +   }
  1.1080 +
  1.1081 +   /* compression_type should always be zero */
  1.1082 +   compression_type = *profile++;
  1.1083 +   if (compression_type)
  1.1084 +   {
  1.1085 +      png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
  1.1086 +      compression_type = 0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
  1.1087 +                                 wrote nonzero) */
  1.1088 +   }
  1.1089 +
  1.1090 +   prefix_length = profile - png_ptr->chunkdata;
  1.1091 +   png_decompress_chunk(png_ptr, compression_type,
  1.1092 +     slength, prefix_length, &data_length);
  1.1093 +
  1.1094 +   profile_length = data_length - prefix_length;
  1.1095 +
  1.1096 +   if ( prefix_length > data_length || profile_length < 4)
  1.1097 +   {
  1.1098 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1099 +      png_ptr->chunkdata = NULL;
  1.1100 +      png_warning(png_ptr, "Profile size field missing from iCCP chunk");
  1.1101 +      return;
  1.1102 +   }
  1.1103 +
  1.1104 +   /* Check the profile_size recorded in the first 32 bits of the ICC profile */
  1.1105 +   pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
  1.1106 +   profile_size = ((*(pC    ))<<24) |
  1.1107 +                  ((*(pC + 1))<<16) |
  1.1108 +                  ((*(pC + 2))<< 8) |
  1.1109 +                  ((*(pC + 3))    );
  1.1110 +
  1.1111 +   if (profile_size < profile_length)
  1.1112 +      profile_length = profile_size;
  1.1113 +
  1.1114 +   if (profile_size > profile_length)
  1.1115 +   {
  1.1116 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1117 +      png_ptr->chunkdata = NULL;
  1.1118 +      png_warning(png_ptr, "Ignoring truncated iCCP profile.");
  1.1119 +      return;
  1.1120 +   }
  1.1121 +
  1.1122 +   png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
  1.1123 +     compression_type, png_ptr->chunkdata + prefix_length, profile_length);
  1.1124 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1125 +   png_ptr->chunkdata = NULL;
  1.1126 +}
  1.1127 +#endif /* PNG_READ_iCCP_SUPPORTED */
  1.1128 +
  1.1129 +#if defined(PNG_READ_sPLT_SUPPORTED)
  1.1130 +void /* PRIVATE */
  1.1131 +png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1132 +/* Note: this does not properly handle chunks that are > 64K under DOS */
  1.1133 +{
  1.1134 +   png_bytep entry_start;
  1.1135 +   png_sPLT_t new_palette;
  1.1136 +#ifdef PNG_NO_POINTER_INDEXING
  1.1137 +   png_sPLT_entryp pp;
  1.1138 +#endif
  1.1139 +   int data_length, entry_size, i;
  1.1140 +   png_uint_32 skip = 0;
  1.1141 +   png_size_t slength;
  1.1142 +
  1.1143 +   png_debug(1, "in png_handle_sPLT\n");
  1.1144 +
  1.1145 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1146 +      png_error(png_ptr, "Missing IHDR before sPLT");
  1.1147 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1148 +   {
  1.1149 +      png_warning(png_ptr, "Invalid sPLT after IDAT");
  1.1150 +      png_crc_finish(png_ptr, length);
  1.1151 +      return;
  1.1152 +   }
  1.1153 +
  1.1154 +#ifdef PNG_MAX_MALLOC_64K
  1.1155 +   if (length > (png_uint_32)65535L)
  1.1156 +   {
  1.1157 +      png_warning(png_ptr, "sPLT chunk too large to fit in memory");
  1.1158 +      skip = length - (png_uint_32)65535L;
  1.1159 +      length = (png_uint_32)65535L;
  1.1160 +   }
  1.1161 +#endif
  1.1162 +
  1.1163 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1164 +   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
  1.1165 +   slength = (png_size_t)length;
  1.1166 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.1167 +
  1.1168 +   if (png_crc_finish(png_ptr, skip))
  1.1169 +   {
  1.1170 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1171 +      png_ptr->chunkdata = NULL;
  1.1172 +      return;
  1.1173 +   }
  1.1174 +
  1.1175 +   png_ptr->chunkdata[slength] = 0x00;
  1.1176 +
  1.1177 +   for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; entry_start++)
  1.1178 +      /* empty loop to find end of name */ ;
  1.1179 +   ++entry_start;
  1.1180 +
  1.1181 +   /* a sample depth should follow the separator, and we should be on it  */
  1.1182 +   if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
  1.1183 +   {
  1.1184 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1185 +      png_ptr->chunkdata = NULL;
  1.1186 +      png_warning(png_ptr, "malformed sPLT chunk");
  1.1187 +      return;
  1.1188 +   }
  1.1189 +
  1.1190 +   new_palette.depth = *entry_start++;
  1.1191 +   entry_size = (new_palette.depth == 8 ? 6 : 10);
  1.1192 +   data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));
  1.1193 +
  1.1194 +   /* integrity-check the data length */
  1.1195 +   if (data_length % entry_size)
  1.1196 +   {
  1.1197 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1198 +      png_ptr->chunkdata = NULL;
  1.1199 +      png_warning(png_ptr, "sPLT chunk has bad length");
  1.1200 +      return;
  1.1201 +   }
  1.1202 +
  1.1203 +   new_palette.nentries = (png_int_32) ( data_length / entry_size);
  1.1204 +   if ((png_uint_32) new_palette.nentries >
  1.1205 +       (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
  1.1206 +   {
  1.1207 +       png_warning(png_ptr, "sPLT chunk too long");
  1.1208 +       return;
  1.1209 +   }
  1.1210 +   new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
  1.1211 +       png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
  1.1212 +   if (new_palette.entries == NULL)
  1.1213 +   {
  1.1214 +       png_warning(png_ptr, "sPLT chunk requires too much memory");
  1.1215 +       return;
  1.1216 +   }
  1.1217 +
  1.1218 +#ifndef PNG_NO_POINTER_INDEXING
  1.1219 +   for (i = 0; i < new_palette.nentries; i++)
  1.1220 +   {
  1.1221 +      png_sPLT_entryp pp = new_palette.entries + i;
  1.1222 +
  1.1223 +      if (new_palette.depth == 8)
  1.1224 +      {
  1.1225 +          pp->red = *entry_start++;
  1.1226 +          pp->green = *entry_start++;
  1.1227 +          pp->blue = *entry_start++;
  1.1228 +          pp->alpha = *entry_start++;
  1.1229 +      }
  1.1230 +      else
  1.1231 +      {
  1.1232 +          pp->red   = png_get_uint_16(entry_start); entry_start += 2;
  1.1233 +          pp->green = png_get_uint_16(entry_start); entry_start += 2;
  1.1234 +          pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
  1.1235 +          pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
  1.1236 +      }
  1.1237 +      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
  1.1238 +   }
  1.1239 +#else
  1.1240 +   pp = new_palette.entries;
  1.1241 +   for (i = 0; i < new_palette.nentries; i++)
  1.1242 +   {
  1.1243 +
  1.1244 +      if (new_palette.depth == 8)
  1.1245 +      {
  1.1246 +          pp[i].red   = *entry_start++;
  1.1247 +          pp[i].green = *entry_start++;
  1.1248 +          pp[i].blue  = *entry_start++;
  1.1249 +          pp[i].alpha = *entry_start++;
  1.1250 +      }
  1.1251 +      else
  1.1252 +      {
  1.1253 +          pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
  1.1254 +          pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
  1.1255 +          pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
  1.1256 +          pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
  1.1257 +      }
  1.1258 +      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
  1.1259 +   }
  1.1260 +#endif
  1.1261 +
  1.1262 +   /* discard all chunk data except the name and stash that */
  1.1263 +   new_palette.name = png_ptr->chunkdata;
  1.1264 +
  1.1265 +   png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
  1.1266 +
  1.1267 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1268 +   png_ptr->chunkdata = NULL;
  1.1269 +   png_free(png_ptr, new_palette.entries);
  1.1270 +}
  1.1271 +#endif /* PNG_READ_sPLT_SUPPORTED */
  1.1272 +
  1.1273 +#if defined(PNG_READ_tRNS_SUPPORTED)
  1.1274 +void /* PRIVATE */
  1.1275 +png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1276 +{
  1.1277 +   png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
  1.1278 +
  1.1279 +   png_debug(1, "in png_handle_tRNS\n");
  1.1280 +
  1.1281 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1282 +      png_error(png_ptr, "Missing IHDR before tRNS");
  1.1283 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1284 +   {
  1.1285 +      png_warning(png_ptr, "Invalid tRNS after IDAT");
  1.1286 +      png_crc_finish(png_ptr, length);
  1.1287 +      return;
  1.1288 +   }
  1.1289 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
  1.1290 +   {
  1.1291 +      png_warning(png_ptr, "Duplicate tRNS chunk");
  1.1292 +      png_crc_finish(png_ptr, length);
  1.1293 +      return;
  1.1294 +   }
  1.1295 +
  1.1296 +   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
  1.1297 +   {
  1.1298 +      png_byte buf[2];
  1.1299 +
  1.1300 +      if (length != 2)
  1.1301 +      {
  1.1302 +         png_warning(png_ptr, "Incorrect tRNS chunk length");
  1.1303 +         png_crc_finish(png_ptr, length);
  1.1304 +         return;
  1.1305 +      }
  1.1306 +
  1.1307 +      png_crc_read(png_ptr, buf, 2);
  1.1308 +      png_ptr->num_trans = 1;
  1.1309 +      png_ptr->trans_values.gray = png_get_uint_16(buf);
  1.1310 +   }
  1.1311 +   else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
  1.1312 +   {
  1.1313 +      png_byte buf[6];
  1.1314 +
  1.1315 +      if (length != 6)
  1.1316 +      {
  1.1317 +         png_warning(png_ptr, "Incorrect tRNS chunk length");
  1.1318 +         png_crc_finish(png_ptr, length);
  1.1319 +         return;
  1.1320 +      }
  1.1321 +      png_crc_read(png_ptr, buf, (png_size_t)length);
  1.1322 +      png_ptr->num_trans = 1;
  1.1323 +      png_ptr->trans_values.red = png_get_uint_16(buf);
  1.1324 +      png_ptr->trans_values.green = png_get_uint_16(buf + 2);
  1.1325 +      png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
  1.1326 +   }
  1.1327 +   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
  1.1328 +   {
  1.1329 +      if (!(png_ptr->mode & PNG_HAVE_PLTE))
  1.1330 +      {
  1.1331 +         /* Should be an error, but we can cope with it. */
  1.1332 +         png_warning(png_ptr, "Missing PLTE before tRNS");
  1.1333 +      }
  1.1334 +      if (length > (png_uint_32)png_ptr->num_palette ||
  1.1335 +          length > PNG_MAX_PALETTE_LENGTH)
  1.1336 +      {
  1.1337 +         png_warning(png_ptr, "Incorrect tRNS chunk length");
  1.1338 +         png_crc_finish(png_ptr, length);
  1.1339 +         return;
  1.1340 +      }
  1.1341 +      if (length == 0)
  1.1342 +      {
  1.1343 +         png_warning(png_ptr, "Zero length tRNS chunk");
  1.1344 +         png_crc_finish(png_ptr, length);
  1.1345 +         return;
  1.1346 +      }
  1.1347 +      png_crc_read(png_ptr, readbuf, (png_size_t)length);
  1.1348 +      png_ptr->num_trans = (png_uint_16)length;
  1.1349 +   }
  1.1350 +   else
  1.1351 +   {
  1.1352 +      png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
  1.1353 +      png_crc_finish(png_ptr, length);
  1.1354 +      return;
  1.1355 +   }
  1.1356 +
  1.1357 +   if (png_crc_finish(png_ptr, 0))
  1.1358 +   {
  1.1359 +      png_ptr->num_trans = 0;
  1.1360 +      return;
  1.1361 +   }
  1.1362 +
  1.1363 +   png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
  1.1364 +      &(png_ptr->trans_values));
  1.1365 +}
  1.1366 +#endif
  1.1367 +
  1.1368 +#if defined(PNG_READ_bKGD_SUPPORTED)
  1.1369 +void /* PRIVATE */
  1.1370 +png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1371 +{
  1.1372 +   png_size_t truelen;
  1.1373 +   png_byte buf[6];
  1.1374 +
  1.1375 +   png_debug(1, "in png_handle_bKGD\n");
  1.1376 +
  1.1377 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1378 +      png_error(png_ptr, "Missing IHDR before bKGD");
  1.1379 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1380 +   {
  1.1381 +      png_warning(png_ptr, "Invalid bKGD after IDAT");
  1.1382 +      png_crc_finish(png_ptr, length);
  1.1383 +      return;
  1.1384 +   }
  1.1385 +   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
  1.1386 +            !(png_ptr->mode & PNG_HAVE_PLTE))
  1.1387 +   {
  1.1388 +      png_warning(png_ptr, "Missing PLTE before bKGD");
  1.1389 +      png_crc_finish(png_ptr, length);
  1.1390 +      return;
  1.1391 +   }
  1.1392 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
  1.1393 +   {
  1.1394 +      png_warning(png_ptr, "Duplicate bKGD chunk");
  1.1395 +      png_crc_finish(png_ptr, length);
  1.1396 +      return;
  1.1397 +   }
  1.1398 +
  1.1399 +   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
  1.1400 +      truelen = 1;
  1.1401 +   else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
  1.1402 +      truelen = 6;
  1.1403 +   else
  1.1404 +      truelen = 2;
  1.1405 +
  1.1406 +   if (length != truelen)
  1.1407 +   {
  1.1408 +      png_warning(png_ptr, "Incorrect bKGD chunk length");
  1.1409 +      png_crc_finish(png_ptr, length);
  1.1410 +      return;
  1.1411 +   }
  1.1412 +
  1.1413 +   png_crc_read(png_ptr, buf, truelen);
  1.1414 +   if (png_crc_finish(png_ptr, 0))
  1.1415 +      return;
  1.1416 +
  1.1417 +   /* We convert the index value into RGB components so that we can allow
  1.1418 +    * arbitrary RGB values for background when we have transparency, and
  1.1419 +    * so it is easy to determine the RGB values of the background color
  1.1420 +    * from the info_ptr struct. */
  1.1421 +   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
  1.1422 +   {
  1.1423 +      png_ptr->background.index = buf[0];
  1.1424 +      if (info_ptr && info_ptr->num_palette)
  1.1425 +      {
  1.1426 +          if (buf[0] > info_ptr->num_palette)
  1.1427 +          {
  1.1428 +             png_warning(png_ptr, "Incorrect bKGD chunk index value");
  1.1429 +             return;
  1.1430 +          }
  1.1431 +          png_ptr->background.red =
  1.1432 +             (png_uint_16)png_ptr->palette[buf[0]].red;
  1.1433 +          png_ptr->background.green =
  1.1434 +             (png_uint_16)png_ptr->palette[buf[0]].green;
  1.1435 +          png_ptr->background.blue =
  1.1436 +             (png_uint_16)png_ptr->palette[buf[0]].blue;
  1.1437 +      }
  1.1438 +   }
  1.1439 +   else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
  1.1440 +   {
  1.1441 +      png_ptr->background.red =
  1.1442 +      png_ptr->background.green =
  1.1443 +      png_ptr->background.blue =
  1.1444 +      png_ptr->background.gray = png_get_uint_16(buf);
  1.1445 +   }
  1.1446 +   else
  1.1447 +   {
  1.1448 +      png_ptr->background.red = png_get_uint_16(buf);
  1.1449 +      png_ptr->background.green = png_get_uint_16(buf + 2);
  1.1450 +      png_ptr->background.blue = png_get_uint_16(buf + 4);
  1.1451 +   }
  1.1452 +
  1.1453 +   png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
  1.1454 +}
  1.1455 +#endif
  1.1456 +
  1.1457 +#if defined(PNG_READ_hIST_SUPPORTED)
  1.1458 +void /* PRIVATE */
  1.1459 +png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1460 +{
  1.1461 +   unsigned int num, i;
  1.1462 +   png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
  1.1463 +
  1.1464 +   png_debug(1, "in png_handle_hIST\n");
  1.1465 +
  1.1466 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1467 +      png_error(png_ptr, "Missing IHDR before hIST");
  1.1468 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1469 +   {
  1.1470 +      png_warning(png_ptr, "Invalid hIST after IDAT");
  1.1471 +      png_crc_finish(png_ptr, length);
  1.1472 +      return;
  1.1473 +   }
  1.1474 +   else if (!(png_ptr->mode & PNG_HAVE_PLTE))
  1.1475 +   {
  1.1476 +      png_warning(png_ptr, "Missing PLTE before hIST");
  1.1477 +      png_crc_finish(png_ptr, length);
  1.1478 +      return;
  1.1479 +   }
  1.1480 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
  1.1481 +   {
  1.1482 +      png_warning(png_ptr, "Duplicate hIST chunk");
  1.1483 +      png_crc_finish(png_ptr, length);
  1.1484 +      return;
  1.1485 +   }
  1.1486 +
  1.1487 +   num = length / 2 ;
  1.1488 +   if (num != (unsigned int) png_ptr->num_palette || num >
  1.1489 +      (unsigned int) PNG_MAX_PALETTE_LENGTH)
  1.1490 +   {
  1.1491 +      png_warning(png_ptr, "Incorrect hIST chunk length");
  1.1492 +      png_crc_finish(png_ptr, length);
  1.1493 +      return;
  1.1494 +   }
  1.1495 +
  1.1496 +   for (i = 0; i < num; i++)
  1.1497 +   {
  1.1498 +      png_byte buf[2];
  1.1499 +
  1.1500 +      png_crc_read(png_ptr, buf, 2);
  1.1501 +      readbuf[i] = png_get_uint_16(buf);
  1.1502 +   }
  1.1503 +
  1.1504 +   if (png_crc_finish(png_ptr, 0))
  1.1505 +      return;
  1.1506 +
  1.1507 +   png_set_hIST(png_ptr, info_ptr, readbuf);
  1.1508 +}
  1.1509 +#endif
  1.1510 +
  1.1511 +#if defined(PNG_READ_pHYs_SUPPORTED)
  1.1512 +void /* PRIVATE */
  1.1513 +png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1514 +{
  1.1515 +   png_byte buf[9];
  1.1516 +   png_uint_32 res_x, res_y;
  1.1517 +   int unit_type;
  1.1518 +
  1.1519 +   png_debug(1, "in png_handle_pHYs\n");
  1.1520 +
  1.1521 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1522 +      png_error(png_ptr, "Missing IHDR before pHYs");
  1.1523 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1524 +   {
  1.1525 +      png_warning(png_ptr, "Invalid pHYs after IDAT");
  1.1526 +      png_crc_finish(png_ptr, length);
  1.1527 +      return;
  1.1528 +   }
  1.1529 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
  1.1530 +   {
  1.1531 +      png_warning(png_ptr, "Duplicate pHYs chunk");
  1.1532 +      png_crc_finish(png_ptr, length);
  1.1533 +      return;
  1.1534 +   }
  1.1535 +
  1.1536 +   if (length != 9)
  1.1537 +   {
  1.1538 +      png_warning(png_ptr, "Incorrect pHYs chunk length");
  1.1539 +      png_crc_finish(png_ptr, length);
  1.1540 +      return;
  1.1541 +   }
  1.1542 +
  1.1543 +   png_crc_read(png_ptr, buf, 9);
  1.1544 +   if (png_crc_finish(png_ptr, 0))
  1.1545 +      return;
  1.1546 +
  1.1547 +   res_x = png_get_uint_32(buf);
  1.1548 +   res_y = png_get_uint_32(buf + 4);
  1.1549 +   unit_type = buf[8];
  1.1550 +   png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
  1.1551 +}
  1.1552 +#endif
  1.1553 +
  1.1554 +#if defined(PNG_READ_oFFs_SUPPORTED)
  1.1555 +void /* PRIVATE */
  1.1556 +png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1557 +{
  1.1558 +   png_byte buf[9];
  1.1559 +   png_int_32 offset_x, offset_y;
  1.1560 +   int unit_type;
  1.1561 +
  1.1562 +   png_debug(1, "in png_handle_oFFs\n");
  1.1563 +
  1.1564 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1565 +      png_error(png_ptr, "Missing IHDR before oFFs");
  1.1566 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1567 +   {
  1.1568 +      png_warning(png_ptr, "Invalid oFFs after IDAT");
  1.1569 +      png_crc_finish(png_ptr, length);
  1.1570 +      return;
  1.1571 +   }
  1.1572 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
  1.1573 +   {
  1.1574 +      png_warning(png_ptr, "Duplicate oFFs chunk");
  1.1575 +      png_crc_finish(png_ptr, length);
  1.1576 +      return;
  1.1577 +   }
  1.1578 +
  1.1579 +   if (length != 9)
  1.1580 +   {
  1.1581 +      png_warning(png_ptr, "Incorrect oFFs chunk length");
  1.1582 +      png_crc_finish(png_ptr, length);
  1.1583 +      return;
  1.1584 +   }
  1.1585 +
  1.1586 +   png_crc_read(png_ptr, buf, 9);
  1.1587 +   if (png_crc_finish(png_ptr, 0))
  1.1588 +      return;
  1.1589 +
  1.1590 +   offset_x = png_get_int_32(buf);
  1.1591 +   offset_y = png_get_int_32(buf + 4);
  1.1592 +   unit_type = buf[8];
  1.1593 +   png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
  1.1594 +}
  1.1595 +#endif
  1.1596 +
  1.1597 +#if defined(PNG_READ_pCAL_SUPPORTED)
  1.1598 +/* read the pCAL chunk (described in the PNG Extensions document) */
  1.1599 +void /* PRIVATE */
  1.1600 +png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1601 +{
  1.1602 +   png_int_32 X0, X1;
  1.1603 +   png_byte type, nparams;
  1.1604 +   png_charp buf, units, endptr;
  1.1605 +   png_charpp params;
  1.1606 +   png_size_t slength;
  1.1607 +   int i;
  1.1608 +
  1.1609 +   png_debug(1, "in png_handle_pCAL\n");
  1.1610 +
  1.1611 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1612 +      png_error(png_ptr, "Missing IHDR before pCAL");
  1.1613 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1614 +   {
  1.1615 +      png_warning(png_ptr, "Invalid pCAL after IDAT");
  1.1616 +      png_crc_finish(png_ptr, length);
  1.1617 +      return;
  1.1618 +   }
  1.1619 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
  1.1620 +   {
  1.1621 +      png_warning(png_ptr, "Duplicate pCAL chunk");
  1.1622 +      png_crc_finish(png_ptr, length);
  1.1623 +      return;
  1.1624 +   }
  1.1625 +
  1.1626 +   png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n",
  1.1627 +      length + 1);
  1.1628 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1629 +   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
  1.1630 +   if (png_ptr->chunkdata == NULL)
  1.1631 +     {
  1.1632 +       png_warning(png_ptr, "No memory for pCAL purpose.");
  1.1633 +       return;
  1.1634 +     }
  1.1635 +   slength = (png_size_t)length;
  1.1636 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.1637 +
  1.1638 +   if (png_crc_finish(png_ptr, 0))
  1.1639 +   {
  1.1640 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1641 +      png_ptr->chunkdata = NULL;
  1.1642 +      return;
  1.1643 +   }
  1.1644 +
  1.1645 +   png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
  1.1646 +
  1.1647 +   png_debug(3, "Finding end of pCAL purpose string\n");
  1.1648 +   for (buf = png_ptr->chunkdata; *buf; buf++)
  1.1649 +      /* empty loop */ ;
  1.1650 +
  1.1651 +   endptr = png_ptr->chunkdata + slength;
  1.1652 +
  1.1653 +   /* We need to have at least 12 bytes after the purpose string
  1.1654 +      in order to get the parameter information. */
  1.1655 +   if (endptr <= buf + 12)
  1.1656 +   {
  1.1657 +      png_warning(png_ptr, "Invalid pCAL data");
  1.1658 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1659 +      png_ptr->chunkdata = NULL;
  1.1660 +      return;
  1.1661 +   }
  1.1662 +
  1.1663 +   png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
  1.1664 +   X0 = png_get_int_32((png_bytep)buf+1);
  1.1665 +   X1 = png_get_int_32((png_bytep)buf+5);
  1.1666 +   type = buf[9];
  1.1667 +   nparams = buf[10];
  1.1668 +   units = buf + 11;
  1.1669 +
  1.1670 +   png_debug(3, "Checking pCAL equation type and number of parameters\n");
  1.1671 +   /* Check that we have the right number of parameters for known
  1.1672 +      equation types. */
  1.1673 +   if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
  1.1674 +       (type == PNG_EQUATION_BASE_E && nparams != 3) ||
  1.1675 +       (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
  1.1676 +       (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
  1.1677 +   {
  1.1678 +      png_warning(png_ptr, "Invalid pCAL parameters for equation type");
  1.1679 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1680 +      png_ptr->chunkdata = NULL;
  1.1681 +      return;
  1.1682 +   }
  1.1683 +   else if (type >= PNG_EQUATION_LAST)
  1.1684 +   {
  1.1685 +      png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
  1.1686 +   }
  1.1687 +
  1.1688 +   for (buf = units; *buf; buf++)
  1.1689 +      /* Empty loop to move past the units string. */ ;
  1.1690 +
  1.1691 +   png_debug(3, "Allocating pCAL parameters array\n");
  1.1692 +   params = (png_charpp)png_malloc_warn(png_ptr,
  1.1693 +      (png_uint_32)(nparams * png_sizeof(png_charp))) ;
  1.1694 +   if (params == NULL)
  1.1695 +     {
  1.1696 +       png_free(png_ptr, png_ptr->chunkdata);
  1.1697 +       png_ptr->chunkdata = NULL;
  1.1698 +       png_warning(png_ptr, "No memory for pCAL params.");
  1.1699 +       return;
  1.1700 +     }
  1.1701 +
  1.1702 +   /* Get pointers to the start of each parameter string. */
  1.1703 +   for (i = 0; i < (int)nparams; i++)
  1.1704 +   {
  1.1705 +      buf++; /* Skip the null string terminator from previous parameter. */
  1.1706 +
  1.1707 +      png_debug1(3, "Reading pCAL parameter %d\n", i);
  1.1708 +      for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
  1.1709 +         /* Empty loop to move past each parameter string */ ;
  1.1710 +
  1.1711 +      /* Make sure we haven't run out of data yet */
  1.1712 +      if (buf > endptr)
  1.1713 +      {
  1.1714 +         png_warning(png_ptr, "Invalid pCAL data");
  1.1715 +         png_free(png_ptr, png_ptr->chunkdata);
  1.1716 +         png_ptr->chunkdata = NULL;
  1.1717 +         png_free(png_ptr, params);
  1.1718 +         return;
  1.1719 +      }
  1.1720 +   }
  1.1721 +
  1.1722 +   png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
  1.1723 +      units, params);
  1.1724 +
  1.1725 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1726 +   png_ptr->chunkdata = NULL;
  1.1727 +   png_free(png_ptr, params);
  1.1728 +}
  1.1729 +#endif
  1.1730 +
  1.1731 +#if defined(PNG_READ_sCAL_SUPPORTED)
  1.1732 +/* read the sCAL chunk */
  1.1733 +void /* PRIVATE */
  1.1734 +png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1735 +{
  1.1736 +   png_charp ep;
  1.1737 +#ifdef PNG_FLOATING_POINT_SUPPORTED
  1.1738 +   double width, height;
  1.1739 +   png_charp vp;
  1.1740 +#else
  1.1741 +#ifdef PNG_FIXED_POINT_SUPPORTED
  1.1742 +   png_charp swidth, sheight;
  1.1743 +#endif
  1.1744 +#endif
  1.1745 +   png_size_t slength;
  1.1746 +
  1.1747 +   png_debug(1, "in png_handle_sCAL\n");
  1.1748 +
  1.1749 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1750 +      png_error(png_ptr, "Missing IHDR before sCAL");
  1.1751 +   else if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1752 +   {
  1.1753 +      png_warning(png_ptr, "Invalid sCAL after IDAT");
  1.1754 +      png_crc_finish(png_ptr, length);
  1.1755 +      return;
  1.1756 +   }
  1.1757 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
  1.1758 +   {
  1.1759 +      png_warning(png_ptr, "Duplicate sCAL chunk");
  1.1760 +      png_crc_finish(png_ptr, length);
  1.1761 +      return;
  1.1762 +   }
  1.1763 +
  1.1764 +   png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n",
  1.1765 +      length + 1);
  1.1766 +   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
  1.1767 +   if (png_ptr->chunkdata == NULL)
  1.1768 +   {
  1.1769 +      png_warning(png_ptr, "Out of memory while processing sCAL chunk");
  1.1770 +      return;
  1.1771 +   }
  1.1772 +   slength = (png_size_t)length;
  1.1773 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.1774 +
  1.1775 +   if (png_crc_finish(png_ptr, 0))
  1.1776 +   {
  1.1777 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1778 +      png_ptr->chunkdata = NULL;
  1.1779 +      return;
  1.1780 +   }
  1.1781 +
  1.1782 +   png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
  1.1783 +
  1.1784 +   ep = png_ptr->chunkdata + 1;        /* skip unit byte */
  1.1785 +
  1.1786 +#ifdef PNG_FLOATING_POINT_SUPPORTED
  1.1787 +   width = png_strtod(png_ptr, ep, &vp);
  1.1788 +   if (*vp)
  1.1789 +   {
  1.1790 +      png_warning(png_ptr, "malformed width string in sCAL chunk");
  1.1791 +      return;
  1.1792 +   }
  1.1793 +#else
  1.1794 +#ifdef PNG_FIXED_POINT_SUPPORTED
  1.1795 +   swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
  1.1796 +   if (swidth == NULL)
  1.1797 +   {
  1.1798 +      png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
  1.1799 +      return;
  1.1800 +   }
  1.1801 +   png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
  1.1802 +#endif
  1.1803 +#endif
  1.1804 +
  1.1805 +   for (ep = png_ptr->chunkdata; *ep; ep++)
  1.1806 +      /* empty loop */ ;
  1.1807 +   ep++;
  1.1808 +
  1.1809 +   if (png_ptr->chunkdata + slength < ep)
  1.1810 +   {
  1.1811 +      png_warning(png_ptr, "Truncated sCAL chunk");
  1.1812 +#if defined(PNG_FIXED_POINT_SUPPORTED) && \
  1.1813 +    !defined(PNG_FLOATING_POINT_SUPPORTED)
  1.1814 +      png_free(png_ptr, swidth);
  1.1815 +#endif
  1.1816 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1817 +      png_ptr->chunkdata = NULL;
  1.1818 +      return;
  1.1819 +   }
  1.1820 +
  1.1821 +#ifdef PNG_FLOATING_POINT_SUPPORTED
  1.1822 +   height = png_strtod(png_ptr, ep, &vp);
  1.1823 +   if (*vp)
  1.1824 +   {
  1.1825 +      png_warning(png_ptr, "malformed height string in sCAL chunk");
  1.1826 +      return;
  1.1827 +   }
  1.1828 +#else
  1.1829 +#ifdef PNG_FIXED_POINT_SUPPORTED
  1.1830 +   sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
  1.1831 +   if (sheight == NULL)
  1.1832 +   {
  1.1833 +      png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
  1.1834 +      return;
  1.1835 +   }
  1.1836 +   png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
  1.1837 +#endif
  1.1838 +#endif
  1.1839 +
  1.1840 +   if (png_ptr->chunkdata + slength < ep
  1.1841 +#ifdef PNG_FLOATING_POINT_SUPPORTED
  1.1842 +      || width <= 0. || height <= 0.
  1.1843 +#endif
  1.1844 +      )
  1.1845 +   {
  1.1846 +      png_warning(png_ptr, "Invalid sCAL data");
  1.1847 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1848 +      png_ptr->chunkdata = NULL;
  1.1849 +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
  1.1850 +      png_free(png_ptr, swidth);
  1.1851 +      png_free(png_ptr, sheight);
  1.1852 +#endif
  1.1853 +      return;
  1.1854 +   }
  1.1855 +
  1.1856 +
  1.1857 +#ifdef PNG_FLOATING_POINT_SUPPORTED
  1.1858 +   png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height);
  1.1859 +#else
  1.1860 +#ifdef PNG_FIXED_POINT_SUPPORTED
  1.1861 +   png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight);
  1.1862 +#endif
  1.1863 +#endif
  1.1864 +
  1.1865 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1866 +   png_ptr->chunkdata = NULL;
  1.1867 +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
  1.1868 +   png_free(png_ptr, swidth);
  1.1869 +   png_free(png_ptr, sheight);
  1.1870 +#endif
  1.1871 +}
  1.1872 +#endif
  1.1873 +
  1.1874 +#if defined(PNG_READ_tIME_SUPPORTED)
  1.1875 +void /* PRIVATE */
  1.1876 +png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1877 +{
  1.1878 +   png_byte buf[7];
  1.1879 +   png_time mod_time;
  1.1880 +
  1.1881 +   png_debug(1, "in png_handle_tIME\n");
  1.1882 +
  1.1883 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1884 +      png_error(png_ptr, "Out of place tIME chunk");
  1.1885 +   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
  1.1886 +   {
  1.1887 +      png_warning(png_ptr, "Duplicate tIME chunk");
  1.1888 +      png_crc_finish(png_ptr, length);
  1.1889 +      return;
  1.1890 +   }
  1.1891 +
  1.1892 +   if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1893 +      png_ptr->mode |= PNG_AFTER_IDAT;
  1.1894 +
  1.1895 +   if (length != 7)
  1.1896 +   {
  1.1897 +      png_warning(png_ptr, "Incorrect tIME chunk length");
  1.1898 +      png_crc_finish(png_ptr, length);
  1.1899 +      return;
  1.1900 +   }
  1.1901 +
  1.1902 +   png_crc_read(png_ptr, buf, 7);
  1.1903 +   if (png_crc_finish(png_ptr, 0))
  1.1904 +      return;
  1.1905 +
  1.1906 +   mod_time.second = buf[6];
  1.1907 +   mod_time.minute = buf[5];
  1.1908 +   mod_time.hour = buf[4];
  1.1909 +   mod_time.day = buf[3];
  1.1910 +   mod_time.month = buf[2];
  1.1911 +   mod_time.year = png_get_uint_16(buf);
  1.1912 +
  1.1913 +   png_set_tIME(png_ptr, info_ptr, &mod_time);
  1.1914 +}
  1.1915 +#endif
  1.1916 +
  1.1917 +#if defined(PNG_READ_tEXt_SUPPORTED)
  1.1918 +/* Note: this does not properly handle chunks that are > 64K under DOS */
  1.1919 +void /* PRIVATE */
  1.1920 +png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.1921 +{
  1.1922 +   png_textp text_ptr;
  1.1923 +   png_charp key;
  1.1924 +   png_charp text;
  1.1925 +   png_uint_32 skip = 0;
  1.1926 +   png_size_t slength;
  1.1927 +   int ret;
  1.1928 +
  1.1929 +   png_debug(1, "in png_handle_tEXt\n");
  1.1930 +
  1.1931 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.1932 +      png_error(png_ptr, "Missing IHDR before tEXt");
  1.1933 +
  1.1934 +   if (png_ptr->mode & PNG_HAVE_IDAT)
  1.1935 +      png_ptr->mode |= PNG_AFTER_IDAT;
  1.1936 +
  1.1937 +#ifdef PNG_MAX_MALLOC_64K
  1.1938 +   if (length > (png_uint_32)65535L)
  1.1939 +   {
  1.1940 +      png_warning(png_ptr, "tEXt chunk too large to fit in memory");
  1.1941 +      skip = length - (png_uint_32)65535L;
  1.1942 +      length = (png_uint_32)65535L;
  1.1943 +   }
  1.1944 +#endif
  1.1945 +
  1.1946 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1947 +   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
  1.1948 +   if (png_ptr->chunkdata == NULL)
  1.1949 +   {
  1.1950 +     png_warning(png_ptr, "No memory to process text chunk.");
  1.1951 +     return;
  1.1952 +   }
  1.1953 +   slength = (png_size_t)length;
  1.1954 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.1955 +
  1.1956 +   if (png_crc_finish(png_ptr, skip))
  1.1957 +   {
  1.1958 +      png_free(png_ptr, png_ptr->chunkdata);
  1.1959 +      png_ptr->chunkdata = NULL;
  1.1960 +      return;
  1.1961 +   }
  1.1962 +
  1.1963 +   key = png_ptr->chunkdata;
  1.1964 +   key[slength] = 0x00;
  1.1965 +
  1.1966 +   for (text = key; *text; text++)
  1.1967 +      /* empty loop to find end of key */ ;
  1.1968 +
  1.1969 +   if (text != key + slength)
  1.1970 +      text++;
  1.1971 +
  1.1972 +   text_ptr = (png_textp)png_malloc_warn(png_ptr,
  1.1973 +      (png_uint_32)png_sizeof(png_text));
  1.1974 +   if (text_ptr == NULL)
  1.1975 +   {
  1.1976 +     png_warning(png_ptr, "Not enough memory to process text chunk.");
  1.1977 +     png_free(png_ptr, png_ptr->chunkdata);
  1.1978 +     png_ptr->chunkdata = NULL;
  1.1979 +     return;
  1.1980 +   }
  1.1981 +   text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
  1.1982 +   text_ptr->key = key;
  1.1983 +#ifdef PNG_iTXt_SUPPORTED
  1.1984 +   text_ptr->lang = NULL;
  1.1985 +   text_ptr->lang_key = NULL;
  1.1986 +   text_ptr->itxt_length = 0;
  1.1987 +#endif
  1.1988 +   text_ptr->text = text;
  1.1989 +   text_ptr->text_length = png_strlen(text);
  1.1990 +
  1.1991 +   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
  1.1992 +
  1.1993 +   png_free(png_ptr, png_ptr->chunkdata);
  1.1994 +   png_ptr->chunkdata = NULL;
  1.1995 +   png_free(png_ptr, text_ptr);
  1.1996 +   if (ret)
  1.1997 +     png_warning(png_ptr, "Insufficient memory to process text chunk.");
  1.1998 +}
  1.1999 +#endif
  1.2000 +
  1.2001 +#if defined(PNG_READ_zTXt_SUPPORTED)
  1.2002 +/* note: this does not correctly handle chunks that are > 64K under DOS */
  1.2003 +void /* PRIVATE */
  1.2004 +png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.2005 +{
  1.2006 +   png_textp text_ptr;
  1.2007 +   png_charp text;
  1.2008 +   int comp_type;
  1.2009 +   int ret;
  1.2010 +   png_size_t slength, prefix_len, data_len;
  1.2011 +
  1.2012 +   png_debug(1, "in png_handle_zTXt\n");
  1.2013 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.2014 +      png_error(png_ptr, "Missing IHDR before zTXt");
  1.2015 +
  1.2016 +   if (png_ptr->mode & PNG_HAVE_IDAT)
  1.2017 +      png_ptr->mode |= PNG_AFTER_IDAT;
  1.2018 +
  1.2019 +#ifdef PNG_MAX_MALLOC_64K
  1.2020 +   /* We will no doubt have problems with chunks even half this size, but
  1.2021 +      there is no hard and fast rule to tell us where to stop. */
  1.2022 +   if (length > (png_uint_32)65535L)
  1.2023 +   {
  1.2024 +     png_warning(png_ptr, "zTXt chunk too large to fit in memory");
  1.2025 +     png_crc_finish(png_ptr, length);
  1.2026 +     return;
  1.2027 +   }
  1.2028 +#endif
  1.2029 +
  1.2030 +   png_free(png_ptr, png_ptr->chunkdata);
  1.2031 +   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
  1.2032 +   if (png_ptr->chunkdata == NULL)
  1.2033 +   {
  1.2034 +     png_warning(png_ptr, "Out of memory processing zTXt chunk.");
  1.2035 +     return;
  1.2036 +   }
  1.2037 +   slength = (png_size_t)length;
  1.2038 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.2039 +   if (png_crc_finish(png_ptr, 0))
  1.2040 +   {
  1.2041 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2042 +      png_ptr->chunkdata = NULL;
  1.2043 +      return;
  1.2044 +   }
  1.2045 +
  1.2046 +   png_ptr->chunkdata[slength] = 0x00;
  1.2047 +
  1.2048 +   for (text = png_ptr->chunkdata; *text; text++)
  1.2049 +      /* empty loop */ ;
  1.2050 +
  1.2051 +   /* zTXt must have some text after the chunkdataword */
  1.2052 +   if (text >= png_ptr->chunkdata + slength - 2)
  1.2053 +   {
  1.2054 +      png_warning(png_ptr, "Truncated zTXt chunk");
  1.2055 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2056 +      png_ptr->chunkdata = NULL;
  1.2057 +      return;
  1.2058 +   }
  1.2059 +   else
  1.2060 +   {
  1.2061 +       comp_type = *(++text);
  1.2062 +       if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
  1.2063 +       {
  1.2064 +          png_warning(png_ptr, "Unknown compression type in zTXt chunk");
  1.2065 +          comp_type = PNG_TEXT_COMPRESSION_zTXt;
  1.2066 +       }
  1.2067 +       text++;        /* skip the compression_method byte */
  1.2068 +   }
  1.2069 +   prefix_len = text - png_ptr->chunkdata;
  1.2070 +
  1.2071 +   png_decompress_chunk(png_ptr, comp_type,
  1.2072 +     (png_size_t)length, prefix_len, &data_len);
  1.2073 +
  1.2074 +   text_ptr = (png_textp)png_malloc_warn(png_ptr,
  1.2075 +      (png_uint_32)png_sizeof(png_text));
  1.2076 +   if (text_ptr == NULL)
  1.2077 +   {
  1.2078 +     png_warning(png_ptr, "Not enough memory to process zTXt chunk.");
  1.2079 +     png_free(png_ptr, png_ptr->chunkdata);
  1.2080 +     png_ptr->chunkdata = NULL;
  1.2081 +     return;
  1.2082 +   }
  1.2083 +   text_ptr->compression = comp_type;
  1.2084 +   text_ptr->key = png_ptr->chunkdata;
  1.2085 +#ifdef PNG_iTXt_SUPPORTED
  1.2086 +   text_ptr->lang = NULL;
  1.2087 +   text_ptr->lang_key = NULL;
  1.2088 +   text_ptr->itxt_length = 0;
  1.2089 +#endif
  1.2090 +   text_ptr->text = png_ptr->chunkdata + prefix_len;
  1.2091 +   text_ptr->text_length = data_len;
  1.2092 +
  1.2093 +   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
  1.2094 +
  1.2095 +   png_free(png_ptr, text_ptr);
  1.2096 +   png_free(png_ptr, png_ptr->chunkdata);
  1.2097 +   png_ptr->chunkdata = NULL;
  1.2098 +   if (ret)
  1.2099 +     png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
  1.2100 +}
  1.2101 +#endif
  1.2102 +
  1.2103 +#if defined(PNG_READ_iTXt_SUPPORTED)
  1.2104 +/* note: this does not correctly handle chunks that are > 64K under DOS */
  1.2105 +void /* PRIVATE */
  1.2106 +png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.2107 +{
  1.2108 +   png_textp text_ptr;
  1.2109 +   png_charp key, lang, text, lang_key;
  1.2110 +   int comp_flag;
  1.2111 +   int comp_type = 0;
  1.2112 +   int ret;
  1.2113 +   png_size_t slength, prefix_len, data_len;
  1.2114 +
  1.2115 +   png_debug(1, "in png_handle_iTXt\n");
  1.2116 +
  1.2117 +   if (!(png_ptr->mode & PNG_HAVE_IHDR))
  1.2118 +      png_error(png_ptr, "Missing IHDR before iTXt");
  1.2119 +
  1.2120 +   if (png_ptr->mode & PNG_HAVE_IDAT)
  1.2121 +      png_ptr->mode |= PNG_AFTER_IDAT;
  1.2122 +
  1.2123 +#ifdef PNG_MAX_MALLOC_64K
  1.2124 +   /* We will no doubt have problems with chunks even half this size, but
  1.2125 +      there is no hard and fast rule to tell us where to stop. */
  1.2126 +   if (length > (png_uint_32)65535L)
  1.2127 +   {
  1.2128 +     png_warning(png_ptr, "iTXt chunk too large to fit in memory");
  1.2129 +     png_crc_finish(png_ptr, length);
  1.2130 +     return;
  1.2131 +   }
  1.2132 +#endif
  1.2133 +
  1.2134 +   png_free(png_ptr, png_ptr->chunkdata);
  1.2135 +   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
  1.2136 +   if (png_ptr->chunkdata == NULL)
  1.2137 +   {
  1.2138 +     png_warning(png_ptr, "No memory to process iTXt chunk.");
  1.2139 +     return;
  1.2140 +   }
  1.2141 +   slength = (png_size_t)length;
  1.2142 +   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
  1.2143 +   if (png_crc_finish(png_ptr, 0))
  1.2144 +   {
  1.2145 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2146 +      png_ptr->chunkdata = NULL;
  1.2147 +      return;
  1.2148 +   }
  1.2149 +
  1.2150 +   png_ptr->chunkdata[slength] = 0x00;
  1.2151 +
  1.2152 +   for (lang = png_ptr->chunkdata; *lang; lang++)
  1.2153 +      /* empty loop */ ;
  1.2154 +   lang++;        /* skip NUL separator */
  1.2155 +
  1.2156 +   /* iTXt must have a language tag (possibly empty), two compression bytes,
  1.2157 +      translated keyword (possibly empty), and possibly some text after the
  1.2158 +      keyword */
  1.2159 +
  1.2160 +   if (lang >= png_ptr->chunkdata + slength - 3)
  1.2161 +   {
  1.2162 +      png_warning(png_ptr, "Truncated iTXt chunk");
  1.2163 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2164 +      png_ptr->chunkdata = NULL;
  1.2165 +      return;
  1.2166 +   }
  1.2167 +   else
  1.2168 +   {
  1.2169 +       comp_flag = *lang++;
  1.2170 +       comp_type = *lang++;
  1.2171 +   }
  1.2172 +
  1.2173 +   for (lang_key = lang; *lang_key; lang_key++)
  1.2174 +      /* empty loop */ ;
  1.2175 +   lang_key++;        /* skip NUL separator */
  1.2176 +
  1.2177 +   if (lang_key >= png_ptr->chunkdata + slength)
  1.2178 +   {
  1.2179 +      png_warning(png_ptr, "Truncated iTXt chunk");
  1.2180 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2181 +      png_ptr->chunkdata = NULL;
  1.2182 +      return;
  1.2183 +   }
  1.2184 +
  1.2185 +   for (text = lang_key; *text; text++)
  1.2186 +      /* empty loop */ ;
  1.2187 +   text++;        /* skip NUL separator */
  1.2188 +   if (text >= png_ptr->chunkdata + slength)
  1.2189 +   {
  1.2190 +      png_warning(png_ptr, "Malformed iTXt chunk");
  1.2191 +      png_free(png_ptr, png_ptr->chunkdata);
  1.2192 +      png_ptr->chunkdata = NULL;
  1.2193 +      return;
  1.2194 +   }
  1.2195 +
  1.2196 +   prefix_len = text - png_ptr->chunkdata;
  1.2197 +
  1.2198 +   key=png_ptr->chunkdata;
  1.2199 +   if (comp_flag)
  1.2200 +       png_decompress_chunk(png_ptr, comp_type,
  1.2201 +         (size_t)length, prefix_len, &data_len);
  1.2202 +   else
  1.2203 +       data_len = png_strlen(png_ptr->chunkdata + prefix_len);
  1.2204 +   text_ptr = (png_textp)png_malloc_warn(png_ptr,
  1.2205 +      (png_uint_32)png_sizeof(png_text));
  1.2206 +   if (text_ptr == NULL)
  1.2207 +   {
  1.2208 +     png_warning(png_ptr, "Not enough memory to process iTXt chunk.");
  1.2209 +     png_free(png_ptr, png_ptr->chunkdata);
  1.2210 +     png_ptr->chunkdata = NULL;
  1.2211 +     return;
  1.2212 +   }
  1.2213 +   text_ptr->compression = (int)comp_flag + 1;
  1.2214 +   text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
  1.2215 +   text_ptr->lang = png_ptr->chunkdata + (lang - key);
  1.2216 +   text_ptr->itxt_length = data_len;
  1.2217 +   text_ptr->text_length = 0;
  1.2218 +   text_ptr->key = png_ptr->chunkdata;
  1.2219 +   text_ptr->text = png_ptr->chunkdata + prefix_len;
  1.2220 +
  1.2221 +   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
  1.2222 +
  1.2223 +   png_free(png_ptr, text_ptr);
  1.2224 +   png_free(png_ptr, png_ptr->chunkdata);
  1.2225 +   png_ptr->chunkdata = NULL;
  1.2226 +   if (ret)
  1.2227 +     png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
  1.2228 +}
  1.2229 +#endif
  1.2230 +
  1.2231 +/* This function is called when we haven't found a handler for a
  1.2232 +   chunk.  If there isn't a problem with the chunk itself (ie bad
  1.2233 +   chunk name, CRC, or a critical chunk), the chunk is silently ignored
  1.2234 +   -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
  1.2235 +   case it will be saved away to be written out later. */
  1.2236 +void /* PRIVATE */
  1.2237 +png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  1.2238 +{
  1.2239 +   png_uint_32 skip = 0;
  1.2240 +
  1.2241 +   png_debug(1, "in png_handle_unknown\n");
  1.2242 +
  1.2243 +   if (png_ptr->mode & PNG_HAVE_IDAT)
  1.2244 +   {
  1.2245 +#ifdef PNG_USE_LOCAL_ARRAYS
  1.2246 +      PNG_CONST PNG_IDAT;
  1.2247 +#endif
  1.2248 +      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))  /* not an IDAT */
  1.2249 +         png_ptr->mode |= PNG_AFTER_IDAT;
  1.2250 +   }
  1.2251 +
  1.2252 +   if (!(png_ptr->chunk_name[0] & 0x20))
  1.2253 +   {
  1.2254 +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
  1.2255 +      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
  1.2256 +           PNG_HANDLE_CHUNK_ALWAYS
  1.2257 +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
  1.2258 +           && png_ptr->read_user_chunk_fn == NULL
  1.2259 +#endif
  1.2260 +        )
  1.2261 +#endif
  1.2262 +          png_chunk_error(png_ptr, "unknown critical chunk");
  1.2263 +   }
  1.2264 +
  1.2265 +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
  1.2266 +   if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) ||
  1.2267 +       (png_ptr->read_user_chunk_fn != NULL))
  1.2268 +   {
  1.2269 +#ifdef PNG_MAX_MALLOC_64K
  1.2270 +       if (length > (png_uint_32)65535L)
  1.2271 +       {
  1.2272 +           png_warning(png_ptr, "unknown chunk too large to fit in memory");
  1.2273 +           skip = length - (png_uint_32)65535L;
  1.2274 +           length = (png_uint_32)65535L;
  1.2275 +       }
  1.2276 +#endif
  1.2277 +       png_memcpy((png_charp)png_ptr->unknown_chunk.name,
  1.2278 +                  (png_charp)png_ptr->chunk_name, 
  1.2279 +                  png_sizeof(png_ptr->unknown_chunk.name));
  1.2280 +       png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] = '\0';
  1.2281 +       png_ptr->unknown_chunk.size = (png_size_t)length;
  1.2282 +       if (length == 0)
  1.2283 +         png_ptr->unknown_chunk.data = NULL;
  1.2284 +       else
  1.2285 +       {
  1.2286 +         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
  1.2287 +         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
  1.2288 +       }
  1.2289 +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
  1.2290 +       if (png_ptr->read_user_chunk_fn != NULL)
  1.2291 +       {
  1.2292 +          /* callback to user unknown chunk handler */
  1.2293 +          int ret;
  1.2294 +          ret = (*(png_ptr->read_user_chunk_fn))
  1.2295 +            (png_ptr, &png_ptr->unknown_chunk);
  1.2296 +          if (ret < 0)
  1.2297 +             png_chunk_error(png_ptr, "error in user chunk");
  1.2298 +          if (ret == 0)
  1.2299 +          {
  1.2300 +             if (!(png_ptr->chunk_name[0] & 0x20))
  1.2301 +                if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
  1.2302 +                     PNG_HANDLE_CHUNK_ALWAYS)
  1.2303 +                   png_chunk_error(png_ptr, "unknown critical chunk");
  1.2304 +             png_set_unknown_chunks(png_ptr, info_ptr,
  1.2305 +               &png_ptr->unknown_chunk, 1);
  1.2306 +          }
  1.2307 +       }
  1.2308 +       else
  1.2309 +#endif
  1.2310 +       png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
  1.2311 +       png_free(png_ptr, png_ptr->unknown_chunk.data);
  1.2312 +       png_ptr->unknown_chunk.data = NULL;
  1.2313 +   }
  1.2314 +   else
  1.2315 +#endif
  1.2316 +      skip = length;
  1.2317 +
  1.2318 +   png_crc_finish(png_ptr, skip);
  1.2319 +
  1.2320 +#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
  1.2321 +   info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
  1.2322 +#endif
  1.2323 +}
  1.2324 +
  1.2325 +/* This function is called to verify that a chunk name is valid.
  1.2326 +   This function can't have the "critical chunk check" incorporated
  1.2327 +   into it, since in the future we will need to be able to call user
  1.2328 +   functions to handle unknown critical chunks after we check that
  1.2329 +   the chunk name itself is valid. */
  1.2330 +
  1.2331 +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
  1.2332 +
  1.2333 +void /* PRIVATE */
  1.2334 +png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
  1.2335 +{
  1.2336 +   png_debug(1, "in png_check_chunk_name\n");
  1.2337 +   if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
  1.2338 +       isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
  1.2339 +   {
  1.2340 +      png_chunk_error(png_ptr, "invalid chunk type");
  1.2341 +   }
  1.2342 +}
  1.2343 +
  1.2344 +/* Combines the row recently read in with the existing pixels in the
  1.2345 +   row.  This routine takes care of alpha and transparency if requested.
  1.2346 +   This routine also handles the two methods of progressive display
  1.2347 +   of interlaced images, depending on the mask value.
  1.2348 +   The mask value describes which pixels are to be combined with
  1.2349 +   the row.  The pattern always repeats every 8 pixels, so just 8
  1.2350 +   bits are needed.  A one indicates the pixel is to be combined,
  1.2351 +   a zero indicates the pixel is to be skipped.  This is in addition
  1.2352 +   to any alpha or transparency value associated with the pixel.  If
  1.2353 +   you want all pixels to be combined, pass 0xff (255) in mask.  */
  1.2354 +
  1.2355 +void /* PRIVATE */
  1.2356 +png_combine_row(png_structp png_ptr, png_bytep row, int mask)
  1.2357 +{
  1.2358 +   png_debug(1, "in png_combine_row\n");
  1.2359 +   if (mask == 0xff)
  1.2360 +   {
  1.2361 +      png_memcpy(row, png_ptr->row_buf + 1,
  1.2362 +         PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
  1.2363 +   }
  1.2364 +   else
  1.2365 +   {
  1.2366 +      switch (png_ptr->row_info.pixel_depth)
  1.2367 +      {
  1.2368 +         case 1:
  1.2369 +         {
  1.2370 +            png_bytep sp = png_ptr->row_buf + 1;
  1.2371 +            png_bytep dp = row;
  1.2372 +            int s_inc, s_start, s_end;
  1.2373 +            int m = 0x80;
  1.2374 +            int shift;
  1.2375 +            png_uint_32 i;
  1.2376 +            png_uint_32 row_width = png_ptr->width;
  1.2377 +
  1.2378 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2379 +            if (png_ptr->transformations & PNG_PACKSWAP)
  1.2380 +            {
  1.2381 +                s_start = 0;
  1.2382 +                s_end = 7;
  1.2383 +                s_inc = 1;
  1.2384 +            }
  1.2385 +            else
  1.2386 +#endif
  1.2387 +            {
  1.2388 +                s_start = 7;
  1.2389 +                s_end = 0;
  1.2390 +                s_inc = -1;
  1.2391 +            }
  1.2392 +
  1.2393 +            shift = s_start;
  1.2394 +
  1.2395 +            for (i = 0; i < row_width; i++)
  1.2396 +            {
  1.2397 +               if (m & mask)
  1.2398 +               {
  1.2399 +                  int value;
  1.2400 +
  1.2401 +                  value = (*sp >> shift) & 0x01;
  1.2402 +                  *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
  1.2403 +                  *dp |= (png_byte)(value << shift);
  1.2404 +               }
  1.2405 +
  1.2406 +               if (shift == s_end)
  1.2407 +               {
  1.2408 +                  shift = s_start;
  1.2409 +                  sp++;
  1.2410 +                  dp++;
  1.2411 +               }
  1.2412 +               else
  1.2413 +                  shift += s_inc;
  1.2414 +
  1.2415 +               if (m == 1)
  1.2416 +                  m = 0x80;
  1.2417 +               else
  1.2418 +                  m >>= 1;
  1.2419 +            }
  1.2420 +            break;
  1.2421 +         }
  1.2422 +         case 2:
  1.2423 +         {
  1.2424 +            png_bytep sp = png_ptr->row_buf + 1;
  1.2425 +            png_bytep dp = row;
  1.2426 +            int s_start, s_end, s_inc;
  1.2427 +            int m = 0x80;
  1.2428 +            int shift;
  1.2429 +            png_uint_32 i;
  1.2430 +            png_uint_32 row_width = png_ptr->width;
  1.2431 +            int value;
  1.2432 +
  1.2433 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2434 +            if (png_ptr->transformations & PNG_PACKSWAP)
  1.2435 +            {
  1.2436 +               s_start = 0;
  1.2437 +               s_end = 6;
  1.2438 +               s_inc = 2;
  1.2439 +            }
  1.2440 +            else
  1.2441 +#endif
  1.2442 +            {
  1.2443 +               s_start = 6;
  1.2444 +               s_end = 0;
  1.2445 +               s_inc = -2;
  1.2446 +            }
  1.2447 +
  1.2448 +            shift = s_start;
  1.2449 +
  1.2450 +            for (i = 0; i < row_width; i++)
  1.2451 +            {
  1.2452 +               if (m & mask)
  1.2453 +               {
  1.2454 +                  value = (*sp >> shift) & 0x03;
  1.2455 +                  *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
  1.2456 +                  *dp |= (png_byte)(value << shift);
  1.2457 +               }
  1.2458 +
  1.2459 +               if (shift == s_end)
  1.2460 +               {
  1.2461 +                  shift = s_start;
  1.2462 +                  sp++;
  1.2463 +                  dp++;
  1.2464 +               }
  1.2465 +               else
  1.2466 +                  shift += s_inc;
  1.2467 +               if (m == 1)
  1.2468 +                  m = 0x80;
  1.2469 +               else
  1.2470 +                  m >>= 1;
  1.2471 +            }
  1.2472 +            break;
  1.2473 +         }
  1.2474 +         case 4:
  1.2475 +         {
  1.2476 +            png_bytep sp = png_ptr->row_buf + 1;
  1.2477 +            png_bytep dp = row;
  1.2478 +            int s_start, s_end, s_inc;
  1.2479 +            int m = 0x80;
  1.2480 +            int shift;
  1.2481 +            png_uint_32 i;
  1.2482 +            png_uint_32 row_width = png_ptr->width;
  1.2483 +            int value;
  1.2484 +
  1.2485 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2486 +            if (png_ptr->transformations & PNG_PACKSWAP)
  1.2487 +            {
  1.2488 +               s_start = 0;
  1.2489 +               s_end = 4;
  1.2490 +               s_inc = 4;
  1.2491 +            }
  1.2492 +            else
  1.2493 +#endif
  1.2494 +            {
  1.2495 +               s_start = 4;
  1.2496 +               s_end = 0;
  1.2497 +               s_inc = -4;
  1.2498 +            }
  1.2499 +            shift = s_start;
  1.2500 +
  1.2501 +            for (i = 0; i < row_width; i++)
  1.2502 +            {
  1.2503 +               if (m & mask)
  1.2504 +               {
  1.2505 +                  value = (*sp >> shift) & 0xf;
  1.2506 +                  *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
  1.2507 +                  *dp |= (png_byte)(value << shift);
  1.2508 +               }
  1.2509 +
  1.2510 +               if (shift == s_end)
  1.2511 +               {
  1.2512 +                  shift = s_start;
  1.2513 +                  sp++;
  1.2514 +                  dp++;
  1.2515 +               }
  1.2516 +               else
  1.2517 +                  shift += s_inc;
  1.2518 +               if (m == 1)
  1.2519 +                  m = 0x80;
  1.2520 +               else
  1.2521 +                  m >>= 1;
  1.2522 +            }
  1.2523 +            break;
  1.2524 +         }
  1.2525 +         default:
  1.2526 +         {
  1.2527 +            png_bytep sp = png_ptr->row_buf + 1;
  1.2528 +            png_bytep dp = row;
  1.2529 +            png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
  1.2530 +            png_uint_32 i;
  1.2531 +            png_uint_32 row_width = png_ptr->width;
  1.2532 +            png_byte m = 0x80;
  1.2533 +
  1.2534 +
  1.2535 +            for (i = 0; i < row_width; i++)
  1.2536 +            {
  1.2537 +               if (m & mask)
  1.2538 +               {
  1.2539 +                  png_memcpy(dp, sp, pixel_bytes);
  1.2540 +               }
  1.2541 +
  1.2542 +               sp += pixel_bytes;
  1.2543 +               dp += pixel_bytes;
  1.2544 +
  1.2545 +               if (m == 1)
  1.2546 +                  m = 0x80;
  1.2547 +               else
  1.2548 +                  m >>= 1;
  1.2549 +            }
  1.2550 +            break;
  1.2551 +         }
  1.2552 +      }
  1.2553 +   }
  1.2554 +}
  1.2555 +
  1.2556 +#ifdef PNG_READ_INTERLACING_SUPPORTED
  1.2557 +/* OLD pre-1.0.9 interface:
  1.2558 +void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
  1.2559 +   png_uint_32 transformations)
  1.2560 + */
  1.2561 +void /* PRIVATE */
  1.2562 +png_do_read_interlace(png_structp png_ptr)
  1.2563 +{
  1.2564 +   png_row_infop row_info = &(png_ptr->row_info);
  1.2565 +   png_bytep row = png_ptr->row_buf + 1;
  1.2566 +   int pass = png_ptr->pass;
  1.2567 +   png_uint_32 transformations = png_ptr->transformations;
  1.2568 +#ifdef PNG_USE_LOCAL_ARRAYS
  1.2569 +   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
  1.2570 +   /* offset to next interlace block */
  1.2571 +   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
  1.2572 +#endif
  1.2573 +
  1.2574 +   png_debug(1, "in png_do_read_interlace\n");
  1.2575 +   if (row != NULL && row_info != NULL)
  1.2576 +   {
  1.2577 +      png_uint_32 final_width;
  1.2578 +
  1.2579 +      final_width = row_info->width * png_pass_inc[pass];
  1.2580 +
  1.2581 +      switch (row_info->pixel_depth)
  1.2582 +      {
  1.2583 +         case 1:
  1.2584 +         {
  1.2585 +            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
  1.2586 +            png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
  1.2587 +            int sshift, dshift;
  1.2588 +            int s_start, s_end, s_inc;
  1.2589 +            int jstop = png_pass_inc[pass];
  1.2590 +            png_byte v;
  1.2591 +            png_uint_32 i;
  1.2592 +            int j;
  1.2593 +
  1.2594 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2595 +            if (transformations & PNG_PACKSWAP)
  1.2596 +            {
  1.2597 +                sshift = (int)((row_info->width + 7) & 0x07);
  1.2598 +                dshift = (int)((final_width + 7) & 0x07);
  1.2599 +                s_start = 7;
  1.2600 +                s_end = 0;
  1.2601 +                s_inc = -1;
  1.2602 +            }
  1.2603 +            else
  1.2604 +#endif
  1.2605 +            {
  1.2606 +                sshift = 7 - (int)((row_info->width + 7) & 0x07);
  1.2607 +                dshift = 7 - (int)((final_width + 7) & 0x07);
  1.2608 +                s_start = 0;
  1.2609 +                s_end = 7;
  1.2610 +                s_inc = 1;
  1.2611 +            }
  1.2612 +
  1.2613 +            for (i = 0; i < row_info->width; i++)
  1.2614 +            {
  1.2615 +               v = (png_byte)((*sp >> sshift) & 0x01);
  1.2616 +               for (j = 0; j < jstop; j++)
  1.2617 +               {
  1.2618 +                  *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
  1.2619 +                  *dp |= (png_byte)(v << dshift);
  1.2620 +                  if (dshift == s_end)
  1.2621 +                  {
  1.2622 +                     dshift = s_start;
  1.2623 +                     dp--;
  1.2624 +                  }
  1.2625 +                  else
  1.2626 +                     dshift += s_inc;
  1.2627 +               }
  1.2628 +               if (sshift == s_end)
  1.2629 +               {
  1.2630 +                  sshift = s_start;
  1.2631 +                  sp--;
  1.2632 +               }
  1.2633 +               else
  1.2634 +                  sshift += s_inc;
  1.2635 +            }
  1.2636 +            break;
  1.2637 +         }
  1.2638 +         case 2:
  1.2639 +         {
  1.2640 +            png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
  1.2641 +            png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
  1.2642 +            int sshift, dshift;
  1.2643 +            int s_start, s_end, s_inc;
  1.2644 +            int jstop = png_pass_inc[pass];
  1.2645 +            png_uint_32 i;
  1.2646 +
  1.2647 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2648 +            if (transformations & PNG_PACKSWAP)
  1.2649 +            {
  1.2650 +               sshift = (int)(((row_info->width + 3) & 0x03) << 1);
  1.2651 +               dshift = (int)(((final_width + 3) & 0x03) << 1);
  1.2652 +               s_start = 6;
  1.2653 +               s_end = 0;
  1.2654 +               s_inc = -2;
  1.2655 +            }
  1.2656 +            else
  1.2657 +#endif
  1.2658 +            {
  1.2659 +               sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
  1.2660 +               dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
  1.2661 +               s_start = 0;
  1.2662 +               s_end = 6;
  1.2663 +               s_inc = 2;
  1.2664 +            }
  1.2665 +
  1.2666 +            for (i = 0; i < row_info->width; i++)
  1.2667 +            {
  1.2668 +               png_byte v;
  1.2669 +               int j;
  1.2670 +
  1.2671 +               v = (png_byte)((*sp >> sshift) & 0x03);
  1.2672 +               for (j = 0; j < jstop; j++)
  1.2673 +               {
  1.2674 +                  *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
  1.2675 +                  *dp |= (png_byte)(v << dshift);
  1.2676 +                  if (dshift == s_end)
  1.2677 +                  {
  1.2678 +                     dshift = s_start;
  1.2679 +                     dp--;
  1.2680 +                  }
  1.2681 +                  else
  1.2682 +                     dshift += s_inc;
  1.2683 +               }
  1.2684 +               if (sshift == s_end)
  1.2685 +               {
  1.2686 +                  sshift = s_start;
  1.2687 +                  sp--;
  1.2688 +               }
  1.2689 +               else
  1.2690 +                  sshift += s_inc;
  1.2691 +            }
  1.2692 +            break;
  1.2693 +         }
  1.2694 +         case 4:
  1.2695 +         {
  1.2696 +            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
  1.2697 +            png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
  1.2698 +            int sshift, dshift;
  1.2699 +            int s_start, s_end, s_inc;
  1.2700 +            png_uint_32 i;
  1.2701 +            int jstop = png_pass_inc[pass];
  1.2702 +
  1.2703 +#if defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2704 +            if (transformations & PNG_PACKSWAP)
  1.2705 +            {
  1.2706 +               sshift = (int)(((row_info->width + 1) & 0x01) << 2);
  1.2707 +               dshift = (int)(((final_width + 1) & 0x01) << 2);
  1.2708 +               s_start = 4;
  1.2709 +               s_end = 0;
  1.2710 +               s_inc = -4;
  1.2711 +            }
  1.2712 +            else
  1.2713 +#endif
  1.2714 +            {
  1.2715 +               sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
  1.2716 +               dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
  1.2717 +               s_start = 0;
  1.2718 +               s_end = 4;
  1.2719 +               s_inc = 4;
  1.2720 +            }
  1.2721 +
  1.2722 +            for (i = 0; i < row_info->width; i++)
  1.2723 +            {
  1.2724 +               png_byte v = (png_byte)((*sp >> sshift) & 0xf);
  1.2725 +               int j;
  1.2726 +
  1.2727 +               for (j = 0; j < jstop; j++)
  1.2728 +               {
  1.2729 +                  *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
  1.2730 +                  *dp |= (png_byte)(v << dshift);
  1.2731 +                  if (dshift == s_end)
  1.2732 +                  {
  1.2733 +                     dshift = s_start;
  1.2734 +                     dp--;
  1.2735 +                  }
  1.2736 +                  else
  1.2737 +                     dshift += s_inc;
  1.2738 +               }
  1.2739 +               if (sshift == s_end)
  1.2740 +               {
  1.2741 +                  sshift = s_start;
  1.2742 +                  sp--;
  1.2743 +               }
  1.2744 +               else
  1.2745 +                  sshift += s_inc;
  1.2746 +            }
  1.2747 +            break;
  1.2748 +         }
  1.2749 +         default:
  1.2750 +         {
  1.2751 +            png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
  1.2752 +            png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
  1.2753 +            png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
  1.2754 +
  1.2755 +            int jstop = png_pass_inc[pass];
  1.2756 +            png_uint_32 i;
  1.2757 +
  1.2758 +            for (i = 0; i < row_info->width; i++)
  1.2759 +            {
  1.2760 +               png_byte v[8];
  1.2761 +               int j;
  1.2762 +
  1.2763 +               png_memcpy(v, sp, pixel_bytes);
  1.2764 +               for (j = 0; j < jstop; j++)
  1.2765 +               {
  1.2766 +                  png_memcpy(dp, v, pixel_bytes);
  1.2767 +                  dp -= pixel_bytes;
  1.2768 +               }
  1.2769 +               sp -= pixel_bytes;
  1.2770 +            }
  1.2771 +            break;
  1.2772 +         }
  1.2773 +      }
  1.2774 +      row_info->width = final_width;
  1.2775 +      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
  1.2776 +   }
  1.2777 +#if !defined(PNG_READ_PACKSWAP_SUPPORTED)
  1.2778 +   transformations = transformations; /* silence compiler warning */
  1.2779 +#endif
  1.2780 +}
  1.2781 +#endif /* PNG_READ_INTERLACING_SUPPORTED */
  1.2782 +
  1.2783 +void /* PRIVATE */
  1.2784 +png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
  1.2785 +   png_bytep prev_row, int filter)
  1.2786 +{
  1.2787 +   png_debug(1, "in png_read_filter_row\n");
  1.2788 +   png_debug2(2, "row = %lu, filter = %d\n", png_ptr->row_number, filter);
  1.2789 +   switch (filter)
  1.2790 +   {
  1.2791 +      case PNG_FILTER_VALUE_NONE:
  1.2792 +         break;
  1.2793 +      case PNG_FILTER_VALUE_SUB:
  1.2794 +      {
  1.2795 +         png_uint_32 i;
  1.2796 +         png_uint_32 istop = row_info->rowbytes;
  1.2797 +         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
  1.2798 +         png_bytep rp = row + bpp;
  1.2799 +         png_bytep lp = row;
  1.2800 +
  1.2801 +         for (i = bpp; i < istop; i++)
  1.2802 +         {
  1.2803 +            *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
  1.2804 +            rp++;
  1.2805 +         }
  1.2806 +         break;
  1.2807 +      }
  1.2808 +      case PNG_FILTER_VALUE_UP:
  1.2809 +      {
  1.2810 +         png_uint_32 i;
  1.2811 +         png_uint_32 istop = row_info->rowbytes;
  1.2812 +         png_bytep rp = row;
  1.2813 +         png_bytep pp = prev_row;
  1.2814 +
  1.2815 +         for (i = 0; i < istop; i++)
  1.2816 +         {
  1.2817 +            *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
  1.2818 +            rp++;
  1.2819 +         }
  1.2820 +         break;
  1.2821 +      }
  1.2822 +      case PNG_FILTER_VALUE_AVG:
  1.2823 +      {
  1.2824 +         png_uint_32 i;
  1.2825 +         png_bytep rp = row;
  1.2826 +         png_bytep pp = prev_row;
  1.2827 +         png_bytep lp = row;
  1.2828 +         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
  1.2829 +         png_uint_32 istop = row_info->rowbytes - bpp;
  1.2830 +
  1.2831 +         for (i = 0; i < bpp; i++)
  1.2832 +         {
  1.2833 +            *rp = (png_byte)(((int)(*rp) +
  1.2834 +               ((int)(*pp++) / 2 )) & 0xff);
  1.2835 +            rp++;
  1.2836 +         }
  1.2837 +
  1.2838 +         for (i = 0; i < istop; i++)
  1.2839 +         {
  1.2840 +            *rp = (png_byte)(((int)(*rp) +
  1.2841 +               (int)(*pp++ + *lp++) / 2 ) & 0xff);
  1.2842 +            rp++;
  1.2843 +         }
  1.2844 +         break;
  1.2845 +      }
  1.2846 +      case PNG_FILTER_VALUE_PAETH:
  1.2847 +      {
  1.2848 +         png_uint_32 i;
  1.2849 +         png_bytep rp = row;
  1.2850 +         png_bytep pp = prev_row;
  1.2851 +         png_bytep lp = row;
  1.2852 +         png_bytep cp = prev_row;
  1.2853 +         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
  1.2854 +         png_uint_32 istop=row_info->rowbytes - bpp;
  1.2855 +
  1.2856 +         for (i = 0; i < bpp; i++)
  1.2857 +         {
  1.2858 +            *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
  1.2859 +            rp++;
  1.2860 +         }
  1.2861 +
  1.2862 +         for (i = 0; i < istop; i++)   /* use leftover rp,pp */
  1.2863 +         {
  1.2864 +            int a, b, c, pa, pb, pc, p;
  1.2865 +
  1.2866 +            a = *lp++;
  1.2867 +            b = *pp++;
  1.2868 +            c = *cp++;
  1.2869 +
  1.2870 +            p = b - c;
  1.2871 +            pc = a - c;
  1.2872 +
  1.2873 +#ifdef PNG_USE_ABS
  1.2874 +            pa = abs(p);
  1.2875 +            pb = abs(pc);
  1.2876 +            pc = abs(p + pc);
  1.2877 +#else
  1.2878 +            pa = p < 0 ? -p : p;
  1.2879 +            pb = pc < 0 ? -pc : pc;
  1.2880 +            pc = (p + pc) < 0 ? -(p + pc) : p + pc;
  1.2881 +#endif
  1.2882 +
  1.2883 +            /*
  1.2884 +               if (pa <= pb && pa <= pc)
  1.2885 +                  p = a;
  1.2886 +               else if (pb <= pc)
  1.2887 +                  p = b;
  1.2888 +               else
  1.2889 +                  p = c;
  1.2890 +             */
  1.2891 +
  1.2892 +            p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
  1.2893 +
  1.2894 +            *rp = (png_byte)(((int)(*rp) + p) & 0xff);
  1.2895 +            rp++;
  1.2896 +         }
  1.2897 +         break;
  1.2898 +      }
  1.2899 +      default:
  1.2900 +         png_warning(png_ptr, "Ignoring bad adaptive filter type");
  1.2901 +         *row = 0;
  1.2902 +         break;
  1.2903 +   }
  1.2904 +}
  1.2905 +
  1.2906 +void /* PRIVATE */
  1.2907 +png_read_finish_row(png_structp png_ptr)
  1.2908 +{
  1.2909 +#ifdef PNG_USE_LOCAL_ARRAYS
  1.2910 +#ifdef PNG_READ_INTERLACING_SUPPORTED
  1.2911 +   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
  1.2912 +
  1.2913 +   /* start of interlace block */
  1.2914 +   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
  1.2915 +
  1.2916 +   /* offset to next interlace block */
  1.2917 +   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
  1.2918 +
  1.2919 +   /* start of interlace block in the y direction */
  1.2920 +   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
  1.2921 +
  1.2922 +   /* offset to next interlace block in the y direction */
  1.2923 +   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
  1.2924 +#endif /* PNG_READ_INTERLACING_SUPPORTED */
  1.2925 +#endif
  1.2926 +
  1.2927 +   png_debug(1, "in png_read_finish_row\n");
  1.2928 +   png_ptr->row_number++;
  1.2929 +   if (png_ptr->row_number < png_ptr->num_rows)
  1.2930 +      return;
  1.2931 +
  1.2932 +#ifdef PNG_READ_INTERLACING_SUPPORTED
  1.2933 +   if (png_ptr->interlaced)
  1.2934 +   {
  1.2935 +      png_ptr->row_number = 0;
  1.2936 +      png_memset_check(png_ptr, png_ptr->prev_row, 0,
  1.2937 +         png_ptr->rowbytes + 1);
  1.2938 +      do
  1.2939 +      {
  1.2940 +         png_ptr->pass++;
  1.2941 +         if (png_ptr->pass >= 7)
  1.2942 +            break;
  1.2943 +         png_ptr->iwidth = (png_ptr->width +
  1.2944 +            png_pass_inc[png_ptr->pass] - 1 -
  1.2945 +            png_pass_start[png_ptr->pass]) /
  1.2946 +            png_pass_inc[png_ptr->pass];
  1.2947 +
  1.2948 +         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
  1.2949 +            png_ptr->iwidth) + 1;
  1.2950 +
  1.2951 +         if (!(png_ptr->transformations & PNG_INTERLACE))
  1.2952 +         {
  1.2953 +            png_ptr->num_rows = (png_ptr->height +
  1.2954 +               png_pass_yinc[png_ptr->pass] - 1 -
  1.2955 +               png_pass_ystart[png_ptr->pass]) /
  1.2956 +               png_pass_yinc[png_ptr->pass];
  1.2957 +            if (!(png_ptr->num_rows))
  1.2958 +               continue;
  1.2959 +         }
  1.2960 +         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
  1.2961 +            break;
  1.2962 +      } while (png_ptr->iwidth == 0);
  1.2963 +
  1.2964 +      if (png_ptr->pass < 7)
  1.2965 +         return;
  1.2966 +   }
  1.2967 +#endif /* PNG_READ_INTERLACING_SUPPORTED */
  1.2968 +
  1.2969 +   if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
  1.2970 +   {
  1.2971 +#ifdef PNG_USE_LOCAL_ARRAYS
  1.2972 +      PNG_CONST PNG_IDAT;
  1.2973 +#endif
  1.2974 +      char extra;
  1.2975 +      int ret;
  1.2976 +
  1.2977 +      png_ptr->zstream.next_out = (Byte *)&extra;
  1.2978 +      png_ptr->zstream.avail_out = (uInt)1;
  1.2979 +      for (;;)
  1.2980 +      {
  1.2981 +         if (!(png_ptr->zstream.avail_in))
  1.2982 +         {
  1.2983 +            while (!png_ptr->idat_size)
  1.2984 +            {
  1.2985 +               png_byte chunk_length[4];
  1.2986 +
  1.2987 +               png_crc_finish(png_ptr, 0);
  1.2988 +
  1.2989 +               png_read_data(png_ptr, chunk_length, 4);
  1.2990 +               png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
  1.2991 +               png_reset_crc(png_ptr);
  1.2992 +               png_crc_read(png_ptr, png_ptr->chunk_name, 4);
  1.2993 +               if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
  1.2994 +                  png_error(png_ptr, "Not enough image data");
  1.2995 +
  1.2996 +            }
  1.2997 +            png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
  1.2998 +            png_ptr->zstream.next_in = png_ptr->zbuf;
  1.2999 +            if (png_ptr->zbuf_size > png_ptr->idat_size)
  1.3000 +               png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
  1.3001 +            png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
  1.3002 +            png_ptr->idat_size -= png_ptr->zstream.avail_in;
  1.3003 +         }
  1.3004 +         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
  1.3005 +         if (ret == Z_STREAM_END)
  1.3006 +         {
  1.3007 +            if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
  1.3008 +               png_ptr->idat_size)
  1.3009 +               png_warning(png_ptr, "Extra compressed data");
  1.3010 +            png_ptr->mode |= PNG_AFTER_IDAT;
  1.3011 +            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
  1.3012 +            break;
  1.3013 +         }
  1.3014 +         if (ret != Z_OK)
  1.3015 +            png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
  1.3016 +                      "Decompression Error");
  1.3017 +
  1.3018 +         if (!(png_ptr->zstream.avail_out))
  1.3019 +         {
  1.3020 +            png_warning(png_ptr, "Extra compressed data.");
  1.3021 +            png_ptr->mode |= PNG_AFTER_IDAT;
  1.3022 +            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
  1.3023 +            break;
  1.3024 +         }
  1.3025 +
  1.3026 +      }
  1.3027 +      png_ptr->zstream.avail_out = 0;
  1.3028 +   }
  1.3029 +
  1.3030 +   if (png_ptr->idat_size || png_ptr->zstream.avail_in)
  1.3031 +      png_warning(png_ptr, "Extra compression data");
  1.3032 +
  1.3033 +   inflateReset(&png_ptr->zstream);
  1.3034 +
  1.3035 +   png_ptr->mode |= PNG_AFTER_IDAT;
  1.3036 +}
  1.3037 +
  1.3038 +void /* PRIVATE */
  1.3039 +png_read_start_row(png_structp png_ptr)
  1.3040 +{
  1.3041 +#ifdef PNG_USE_LOCAL_ARRAYS
  1.3042 +#ifdef PNG_READ_INTERLACING_SUPPORTED
  1.3043 +   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
  1.3044 +
  1.3045 +   /* start of interlace block */
  1.3046 +   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
  1.3047 +
  1.3048 +   /* offset to next interlace block */
  1.3049 +   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
  1.3050 +
  1.3051 +   /* start of interlace block in the y direction */
  1.3052 +   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
  1.3053 +
  1.3054 +   /* offset to next interlace block in the y direction */
  1.3055 +   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
  1.3056 +#endif
  1.3057 +#endif
  1.3058 +
  1.3059 +   int max_pixel_depth;
  1.3060 +   png_size_t row_bytes;
  1.3061 +
  1.3062 +   png_debug(1, "in png_read_start_row\n");
  1.3063 +   png_ptr->zstream.avail_in = 0;
  1.3064 +   png_init_read_transformations(png_ptr);
  1.3065 +#ifdef PNG_READ_INTERLACING_SUPPORTED
  1.3066 +   if (png_ptr->interlaced)
  1.3067 +   {
  1.3068 +      if (!(png_ptr->transformations & PNG_INTERLACE))
  1.3069 +         png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
  1.3070 +            png_pass_ystart[0]) / png_pass_yinc[0];
  1.3071 +      else
  1.3072 +         png_ptr->num_rows = png_ptr->height;
  1.3073 +
  1.3074 +      png_ptr->iwidth = (png_ptr->width +
  1.3075 +         png_pass_inc[png_ptr->pass] - 1 -
  1.3076 +         png_pass_start[png_ptr->pass]) /
  1.3077 +         png_pass_inc[png_ptr->pass];
  1.3078 +
  1.3079 +         png_ptr->irowbytes =
  1.3080 +            PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1;
  1.3081 +   }
  1.3082 +   else
  1.3083 +#endif /* PNG_READ_INTERLACING_SUPPORTED */
  1.3084 +   {
  1.3085 +      png_ptr->num_rows = png_ptr->height;
  1.3086 +      png_ptr->iwidth = png_ptr->width;
  1.3087 +      png_ptr->irowbytes = png_ptr->rowbytes + 1;
  1.3088 +   }
  1.3089 +   max_pixel_depth = png_ptr->pixel_depth;
  1.3090 +
  1.3091 +#if defined(PNG_READ_PACK_SUPPORTED)
  1.3092 +   if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
  1.3093 +      max_pixel_depth = 8;
  1.3094 +#endif
  1.3095 +
  1.3096 +#if defined(PNG_READ_EXPAND_SUPPORTED)
  1.3097 +   if (png_ptr->transformations & PNG_EXPAND)
  1.3098 +   {
  1.3099 +      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
  1.3100 +      {
  1.3101 +         if (png_ptr->num_trans)
  1.3102 +            max_pixel_depth = 32;
  1.3103 +         else
  1.3104 +            max_pixel_depth = 24;
  1.3105 +      }
  1.3106 +      else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
  1.3107 +      {
  1.3108 +         if (max_pixel_depth < 8)
  1.3109 +            max_pixel_depth = 8;
  1.3110 +         if (png_ptr->num_trans)
  1.3111 +            max_pixel_depth *= 2;
  1.3112 +      }
  1.3113 +      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
  1.3114 +      {
  1.3115 +         if (png_ptr->num_trans)
  1.3116 +         {
  1.3117 +            max_pixel_depth *= 4;
  1.3118 +            max_pixel_depth /= 3;
  1.3119 +         }
  1.3120 +      }
  1.3121 +   }
  1.3122 +#endif
  1.3123 +
  1.3124 +#if defined(PNG_READ_FILLER_SUPPORTED)
  1.3125 +   if (png_ptr->transformations & (PNG_FILLER))
  1.3126 +   {
  1.3127 +      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
  1.3128 +         max_pixel_depth = 32;
  1.3129 +      else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
  1.3130 +      {
  1.3131 +         if (max_pixel_depth <= 8)
  1.3132 +            max_pixel_depth = 16;
  1.3133 +         else
  1.3134 +            max_pixel_depth = 32;
  1.3135 +      }
  1.3136 +      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
  1.3137 +      {
  1.3138 +         if (max_pixel_depth <= 32)
  1.3139 +            max_pixel_depth = 32;
  1.3140 +         else
  1.3141 +            max_pixel_depth = 64;
  1.3142 +      }
  1.3143 +   }
  1.3144 +#endif
  1.3145 +
  1.3146 +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
  1.3147 +   if (png_ptr->transformations & PNG_GRAY_TO_RGB)
  1.3148 +   {
  1.3149 +      if (
  1.3150 +#if defined(PNG_READ_EXPAND_SUPPORTED)
  1.3151 +        (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
  1.3152 +#endif
  1.3153 +#if defined(PNG_READ_FILLER_SUPPORTED)
  1.3154 +        (png_ptr->transformations & (PNG_FILLER)) ||
  1.3155 +#endif
  1.3156 +        png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
  1.3157 +      {
  1.3158 +         if (max_pixel_depth <= 16)
  1.3159 +            max_pixel_depth = 32;
  1.3160 +         else
  1.3161 +            max_pixel_depth = 64;
  1.3162 +      }
  1.3163 +      else
  1.3164 +      {
  1.3165 +         if (max_pixel_depth <= 8)
  1.3166 +           {
  1.3167 +             if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
  1.3168 +               max_pixel_depth = 32;
  1.3169 +             else
  1.3170 +               max_pixel_depth = 24;
  1.3171 +           }
  1.3172 +         else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
  1.3173 +            max_pixel_depth = 64;
  1.3174 +         else
  1.3175 +            max_pixel_depth = 48;
  1.3176 +      }
  1.3177 +   }
  1.3178 +#endif
  1.3179 +
  1.3180 +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
  1.3181 +defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
  1.3182 +   if (png_ptr->transformations & PNG_USER_TRANSFORM)
  1.3183 +     {
  1.3184 +       int user_pixel_depth = png_ptr->user_transform_depth*
  1.3185 +         png_ptr->user_transform_channels;
  1.3186 +       if (user_pixel_depth > max_pixel_depth)
  1.3187 +         max_pixel_depth=user_pixel_depth;
  1.3188 +     }
  1.3189 +#endif
  1.3190 +
  1.3191 +   /* align the width on the next larger 8 pixels.  Mainly used
  1.3192 +      for interlacing */
  1.3193 +   row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
  1.3194 +   /* calculate the maximum bytes needed, adding a byte and a pixel
  1.3195 +      for safety's sake */
  1.3196 +   row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
  1.3197 +      1 + ((max_pixel_depth + 7) >> 3);
  1.3198 +#ifdef PNG_MAX_MALLOC_64K
  1.3199 +   if (row_bytes > (png_uint_32)65536L)
  1.3200 +      png_error(png_ptr, "This image requires a row greater than 64KB");
  1.3201 +#endif
  1.3202 +
  1.3203 +   if (row_bytes + 64 > png_ptr->old_big_row_buf_size)
  1.3204 +   {
  1.3205 +     png_free(png_ptr, png_ptr->big_row_buf);
  1.3206 +     png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64);
  1.3207 +     png_ptr->row_buf = png_ptr->big_row_buf+32;
  1.3208 +     png_ptr->old_big_row_buf_size = row_bytes+64;
  1.3209 +   }
  1.3210 +
  1.3211 +#ifdef PNG_MAX_MALLOC_64K
  1.3212 +   if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
  1.3213 +      png_error(png_ptr, "This image requires a row greater than 64KB");
  1.3214 +#endif
  1.3215 +   if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
  1.3216 +      png_error(png_ptr, "Row has too many bytes to allocate in memory.");
  1.3217 +
  1.3218 +   if (png_ptr->rowbytes+1 > png_ptr->old_prev_row_size)
  1.3219 +   {
  1.3220 +     png_free(png_ptr, png_ptr->prev_row);
  1.3221 +     png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
  1.3222 +        png_ptr->rowbytes + 1));
  1.3223 +     png_ptr->old_prev_row_size = png_ptr->rowbytes+1;
  1.3224 +   }
  1.3225 +
  1.3226 +   png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
  1.3227 +
  1.3228 +   png_debug1(3, "width = %lu,\n", png_ptr->width);
  1.3229 +   png_debug1(3, "height = %lu,\n", png_ptr->height);
  1.3230 +   png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth);
  1.3231 +   png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows);
  1.3232 +   png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes);
  1.3233 +   png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes);
  1.3234 +
  1.3235 +   png_ptr->flags |= PNG_FLAG_ROW_INIT;
  1.3236 +}
  1.3237 +#endif /* PNG_READ_SUPPORTED */