rev 55557 : 8217676: Upgrade libpng to 1.6.37
Reviewed-by: prr, jdv

   1 /*
   2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.  Oracle designates this
   7  * particular file as subject to the "Classpath" exception as provided
   8  * by Oracle in the LICENSE file that accompanied this code.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  */
  24 
  25 /* pngstruct.h - header file for PNG reference library
  26  *
  27  * This file is available under and governed by the GNU General Public
  28  * License version 2 only, as published by the Free Software Foundation.
  29  * However, the following notice accompanied the original version of this
  30  * file and, per its terms, should not be removed:
  31  *
  32  * Copyright (c) 2018-2019 Cosmin Truta
  33  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  34  * Copyright (c) 1996-1997 Andreas Dilger
  35  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
  36  *
  37  * This code is released under the libpng license.
  38  * For conditions of distribution and use, see the disclaimer
  39  * and license in png.h
  40  */
  41 
  42 /* The structure that holds the information to read and write PNG files.
  43  * The only people who need to care about what is inside of this are the
  44  * people who will be modifying the library for their own special needs.
  45  * It should NOT be accessed directly by an application.
  46  */
  47 
  48 #ifndef PNGSTRUCT_H
  49 #define PNGSTRUCT_H
  50 /* zlib.h defines the structure z_stream, an instance of which is included
  51  * in this structure and is required for decompressing the LZ compressed
  52  * data in PNG files.
  53  */
  54 #ifndef ZLIB_CONST
  55    /* We must ensure that zlib uses 'const' in declarations. */
  56 #  define ZLIB_CONST
  57 #endif
  58 #include "zlib.h"
  59 #ifdef const
  60    /* zlib.h sometimes #defines const to nothing, undo this. */
  61 #  undef const
  62 #endif
  63 
  64 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
  65  * with older builds.
  66  */
  67 #if ZLIB_VERNUM < 0x1260
  68 #  define PNGZ_MSG_CAST(s) png_constcast(char*,s)
  69 #  define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
  70 #else
  71 #  define PNGZ_MSG_CAST(s) (s)
  72 #  define PNGZ_INPUT_CAST(b) (b)
  73 #endif
  74 
  75 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
  76  * can handle at once.  This type need be no larger than 16 bits (so maximum of
  77  * 65535), this define allows us to discover how big it is, but limited by the
  78  * maximum for size_t.  The value can be overridden in a library build
  79  * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
  80  * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
  81  * and may even improve performance on some systems (and degrade it on others.)
  82  */
  83 #ifndef ZLIB_IO_MAX
  84 #  define ZLIB_IO_MAX ((uInt)-1)
  85 #endif
  86 
  87 #ifdef PNG_WRITE_SUPPORTED
  88 /* The type of a compression buffer list used by the write code. */
  89 typedef struct png_compression_buffer
  90 {
  91    struct png_compression_buffer *next;
  92    png_byte                       output[1]; /* actually zbuf_size */
  93 } png_compression_buffer, *png_compression_bufferp;
  94 
  95 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\
  96    (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
  97 #endif
  98 
  99 /* Colorspace support; structures used in png_struct, png_info and in internal
 100  * functions to hold and communicate information about the color space.
 101  *
 102  * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
 103  * colorspace corrections, otherwise all the colorspace information can be
 104  * skipped and the size of libpng can be reduced (significantly) by compiling
 105  * out the colorspace support.
 106  */
 107 #ifdef PNG_COLORSPACE_SUPPORTED
 108 /* The chromaticities of the red, green and blue colorants and the chromaticity
 109  * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
 110  */
 111 typedef struct png_xy
 112 {
 113    png_fixed_point redx, redy;
 114    png_fixed_point greenx, greeny;
 115    png_fixed_point bluex, bluey;
 116    png_fixed_point whitex, whitey;
 117 } png_xy;
 118 
 119 /* The same data as above but encoded as CIE XYZ values.  When this data comes
 120  * from chromaticities the sum of the Y values is assumed to be 1.0
 121  */
 122 typedef struct png_XYZ
 123 {
 124    png_fixed_point red_X, red_Y, red_Z;
 125    png_fixed_point green_X, green_Y, green_Z;
 126    png_fixed_point blue_X, blue_Y, blue_Z;
 127 } png_XYZ;
 128 #endif /* COLORSPACE */
 129 
 130 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
 131 /* A colorspace is all the above plus, potentially, profile information;
 132  * however at present libpng does not use the profile internally so it is only
 133  * stored in the png_info struct (if iCCP is supported.)  The rendering intent
 134  * is retained here and is checked.
 135  *
 136  * The file gamma encoding information is also stored here and gamma correction
 137  * is done by libpng, whereas color correction must currently be done by the
 138  * application.
 139  */
 140 typedef struct png_colorspace
 141 {
 142 #ifdef PNG_GAMMA_SUPPORTED
 143    png_fixed_point gamma;        /* File gamma */
 144 #endif
 145 
 146 #ifdef PNG_COLORSPACE_SUPPORTED
 147    png_xy      end_points_xy;    /* End points as chromaticities */
 148    png_XYZ     end_points_XYZ;   /* End points as CIE XYZ colorant values */
 149    png_uint_16 rendering_intent; /* Rendering intent of a profile */
 150 #endif
 151 
 152    /* Flags are always defined to simplify the code. */
 153    png_uint_16 flags;            /* As defined below */
 154 } png_colorspace, * PNG_RESTRICT png_colorspacerp;
 155 
 156 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
 157 
 158 /* General flags for the 'flags' field */
 159 #define PNG_COLORSPACE_HAVE_GAMMA           0x0001
 160 #define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
 161 #define PNG_COLORSPACE_HAVE_INTENT          0x0004
 162 #define PNG_COLORSPACE_FROM_gAMA            0x0008
 163 #define PNG_COLORSPACE_FROM_cHRM            0x0010
 164 #define PNG_COLORSPACE_FROM_sRGB            0x0020
 165 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
 166 #define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
 167 #define PNG_COLORSPACE_INVALID              0x8000
 168 #define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
 169 #endif /* COLORSPACE || GAMMA */
 170 
 171 struct png_struct_def
 172 {
 173 #ifdef PNG_SETJMP_SUPPORTED
 174    jmp_buf jmp_buf_local;     /* New name in 1.6.0 for jmp_buf in png_struct */
 175    png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
 176    jmp_buf *jmp_buf_ptr;      /* passed to longjmp_fn */
 177    size_t jmp_buf_size;       /* size of the above, if allocated */
 178 #endif
 179    png_error_ptr error_fn;    /* function for printing errors and aborting */
 180 #ifdef PNG_WARNINGS_SUPPORTED
 181    png_error_ptr warning_fn;  /* function for printing warnings */
 182 #endif
 183    png_voidp error_ptr;       /* user supplied struct for error functions */
 184    png_rw_ptr write_data_fn;  /* function for writing output data */
 185    png_rw_ptr read_data_fn;   /* function for reading input data */
 186    png_voidp io_ptr;          /* ptr to application struct for I/O functions */
 187 
 188 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
 189    png_user_transform_ptr read_user_transform_fn; /* user read transform */
 190 #endif
 191 
 192 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
 193    png_user_transform_ptr write_user_transform_fn; /* user write transform */
 194 #endif
 195 
 196 /* These were added in libpng-1.0.2 */
 197 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 198 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
 199     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 200    png_voidp user_transform_ptr; /* user supplied struct for user transform */
 201    png_byte user_transform_depth;    /* bit depth of user transformed pixels */
 202    png_byte user_transform_channels; /* channels in user transformed pixels */
 203 #endif
 204 #endif
 205 
 206    png_uint_32 mode;          /* tells us where we are in the PNG file */
 207    png_uint_32 flags;         /* flags indicating various things to libpng */
 208    png_uint_32 transformations; /* which transformations to perform */
 209 
 210    png_uint_32 zowner;        /* ID (chunk type) of zstream owner, 0 if none */
 211    z_stream    zstream;       /* decompression structure */
 212 
 213 #ifdef PNG_WRITE_SUPPORTED
 214    png_compression_bufferp zbuffer_list; /* Created on demand during write */
 215    uInt                    zbuffer_size; /* size of the actual buffer */
 216 
 217    int zlib_level;            /* holds zlib compression level */
 218    int zlib_method;           /* holds zlib compression method */
 219    int zlib_window_bits;      /* holds zlib compression window bits */
 220    int zlib_mem_level;        /* holds zlib compression memory level */
 221    int zlib_strategy;         /* holds zlib compression strategy */
 222 #endif
 223 /* Added at libpng 1.5.4 */
 224 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 225    int zlib_text_level;            /* holds zlib compression level */
 226    int zlib_text_method;           /* holds zlib compression method */
 227    int zlib_text_window_bits;      /* holds zlib compression window bits */
 228    int zlib_text_mem_level;        /* holds zlib compression memory level */
 229    int zlib_text_strategy;         /* holds zlib compression strategy */
 230 #endif
 231 /* End of material added at libpng 1.5.4 */
 232 /* Added at libpng 1.6.0 */
 233 #ifdef PNG_WRITE_SUPPORTED
 234    int zlib_set_level;        /* Actual values set into the zstream on write */
 235    int zlib_set_method;
 236    int zlib_set_window_bits;
 237    int zlib_set_mem_level;
 238    int zlib_set_strategy;
 239 #endif
 240 
 241    png_uint_32 width;         /* width of image in pixels */
 242    png_uint_32 height;        /* height of image in pixels */
 243    png_uint_32 num_rows;      /* number of rows in current pass */
 244    png_uint_32 usr_width;     /* width of row at start of write */
 245    size_t rowbytes;           /* size of row in bytes */
 246    png_uint_32 iwidth;        /* width of current interlaced row in pixels */
 247    png_uint_32 row_number;    /* current row in interlace pass */
 248    png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
 249    png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
 250                                * While reading this is a pointer into
 251                                * big_prev_row; while writing it is separately
 252                                * allocated if needed.
 253                                */
 254    png_bytep row_buf;         /* buffer to save current (unfiltered) row.
 255                                * While reading, this is a pointer into
 256                                * big_row_buf; while writing it is separately
 257                                * allocated.
 258                                */
 259 #ifdef PNG_WRITE_FILTER_SUPPORTED
 260    png_bytep try_row;    /* buffer to save trial row when filtering */
 261    png_bytep tst_row;    /* buffer to save best trial row when filtering */
 262 #endif
 263    size_t info_rowbytes;      /* Added in 1.5.4: cache of updated row bytes */
 264 
 265    png_uint_32 idat_size;     /* current IDAT size for read */
 266    png_uint_32 crc;           /* current chunk CRC value */
 267    png_colorp palette;        /* palette from the input file */
 268    png_uint_16 num_palette;   /* number of color entries in palette */
 269 
 270 /* Added at libpng-1.5.10 */
 271 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
 272    int num_palette_max;       /* maximum palette index found in IDAT */
 273 #endif
 274 
 275    png_uint_16 num_trans;     /* number of transparency values */
 276    png_byte compression;      /* file compression type (always 0) */
 277    png_byte filter;           /* file filter type (always 0) */
 278    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 279    png_byte pass;             /* current interlace pass (0 - 6) */
 280    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ in png.h ) */
 281    png_byte color_type;       /* color type of file */
 282    png_byte bit_depth;        /* bit depth of file */
 283    png_byte usr_bit_depth;    /* bit depth of users row: write only */
 284    png_byte pixel_depth;      /* number of bits per pixel */
 285    png_byte channels;         /* number of channels in file */
 286 #ifdef PNG_WRITE_SUPPORTED
 287    png_byte usr_channels;     /* channels at start of write: write only */
 288 #endif
 289    png_byte sig_bytes;        /* magic bytes read/written from start of file */
 290    png_byte maximum_pixel_depth;
 291                               /* pixel depth used for the row buffers */
 292    png_byte transformed_pixel_depth;
 293                               /* pixel depth after read/write transforms */
 294 #if ZLIB_VERNUM >= 0x1240
 295    png_byte zstream_start;    /* at start of an input zlib stream */
 296 #endif /* Zlib >= 1.2.4 */
 297 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
 298    png_uint_16 filler;           /* filler bytes for pixel expansion */
 299 #endif
 300 
 301 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
 302    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
 303    png_byte background_gamma_type;
 304    png_fixed_point background_gamma;
 305    png_color_16 background;   /* background color in screen gamma space */
 306 #ifdef PNG_READ_GAMMA_SUPPORTED
 307    png_color_16 background_1; /* background normalized to gamma 1.0 */
 308 #endif
 309 #endif /* bKGD */
 310 
 311 #ifdef PNG_WRITE_FLUSH_SUPPORTED
 312    png_flush_ptr output_flush_fn; /* Function for flushing output */
 313    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
 314    png_uint_32 flush_rows;    /* number of rows written since last flush */
 315 #endif
 316 
 317 #ifdef PNG_READ_GAMMA_SUPPORTED
 318    int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
 319    png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
 320 
 321    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
 322    png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
 323 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
 324    defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
 325    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
 326    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
 327    png_bytep gamma_to_1;      /* converts from file to 1.0 */
 328    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
 329    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
 330 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
 331 #endif
 332 
 333 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
 334    png_color_8 sig_bit;       /* significant bits in each available channel */
 335 #endif
 336 
 337 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 338    png_color_8 shift;         /* shift for significant bit transformation */
 339 #endif
 340 
 341 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
 342  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
 343    png_bytep trans_alpha;           /* alpha values for paletted files */
 344    png_color_16 trans_color;  /* transparent color for non-paletted files */
 345 #endif
 346 
 347    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
 348    png_write_status_ptr write_row_fn; /* called after each row is encoded */
 349 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 350    png_progressive_info_ptr info_fn; /* called after header data fully read */
 351    png_progressive_row_ptr row_fn;   /* called after a prog. row is decoded */
 352    png_progressive_end_ptr end_fn;   /* called after image is complete */
 353    png_bytep save_buffer_ptr;        /* current location in save_buffer */
 354    png_bytep save_buffer;            /* buffer for previously read data */
 355    png_bytep current_buffer_ptr;     /* current location in current_buffer */
 356    png_bytep current_buffer;         /* buffer for recently used data */
 357    png_uint_32 push_length;          /* size of current input chunk */
 358    png_uint_32 skip_length;          /* bytes to skip in input data */
 359    size_t save_buffer_size;          /* amount of data now in save_buffer */
 360    size_t save_buffer_max;           /* total size of save_buffer */
 361    size_t buffer_size;               /* total amount of available input data */
 362    size_t current_buffer_size;       /* amount of data now in current_buffer */
 363    int process_mode;                 /* what push library is currently doing */
 364    int cur_palette;                  /* current push library palette index */
 365 
 366 #endif /* PROGRESSIVE_READ */
 367 
 368 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
 369 /* For the Borland special 64K segment handler */
 370    png_bytepp offset_table_ptr;
 371    png_bytep offset_table;
 372    png_uint_16 offset_table_number;
 373    png_uint_16 offset_table_count;
 374    png_uint_16 offset_table_count_free;
 375 #endif
 376 
 377 #ifdef PNG_READ_QUANTIZE_SUPPORTED
 378    png_bytep palette_lookup; /* lookup table for quantizing */
 379    png_bytep quantize_index; /* index translation for palette files */
 380 #endif
 381 
 382 /* Options */
 383 #ifdef PNG_SET_OPTION_SUPPORTED
 384    png_uint_32 options;           /* On/off state (up to 16 options) */
 385 #endif
 386 
 387 #if PNG_LIBPNG_VER < 10700
 388 /* To do: remove this from libpng-1.7 */
 389 #ifdef PNG_TIME_RFC1123_SUPPORTED
 390    char time_buffer[29]; /* String to hold RFC 1123 time text */
 391 #endif
 392 #endif
 393 
 394 /* New members added in libpng-1.0.6 */
 395 
 396    png_uint_32 free_me;    /* flags items libpng is responsible for freeing */
 397 
 398 #ifdef PNG_USER_CHUNKS_SUPPORTED
 399    png_voidp user_chunk_ptr;
 400 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
 401    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
 402 #endif
 403 #endif
 404 
 405 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 406    int          unknown_default; /* As PNG_HANDLE_* */
 407    unsigned int num_chunk_list;  /* Number of entries in the list */
 408    png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
 409                                   * followed by a PNG_HANDLE_* byte */
 410 #endif
 411 
 412 /* New members added in libpng-1.0.3 */
 413 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 414    png_byte rgb_to_gray_status;
 415    /* Added in libpng 1.5.5 to record setting of coefficients: */
 416    png_byte rgb_to_gray_coefficients_set;
 417    /* These were changed from png_byte in libpng-1.0.6 */
 418    png_uint_16 rgb_to_gray_red_coeff;
 419    png_uint_16 rgb_to_gray_green_coeff;
 420    /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
 421 #endif
 422 
 423 /* New member added in libpng-1.6.36 */
 424 #if defined(PNG_READ_EXPAND_SUPPORTED) && \
 425     defined(PNG_ARM_NEON_IMPLEMENTATION)
 426    png_bytep riffled_palette; /* buffer for accelerated palette expansion */
 427 #endif
 428 
 429 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
 430 #if defined(PNG_MNG_FEATURES_SUPPORTED)
 431 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
 432    png_uint_32 mng_features_permitted;
 433 #endif
 434 
 435 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
 436 #ifdef PNG_MNG_FEATURES_SUPPORTED
 437    png_byte filter_type;
 438 #endif
 439 
 440 /* New members added in libpng-1.2.0 */
 441 
 442 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
 443 #ifdef PNG_USER_MEM_SUPPORTED
 444    png_voidp mem_ptr;             /* user supplied struct for mem functions */
 445    png_malloc_ptr malloc_fn;      /* function for allocating memory */
 446    png_free_ptr free_fn;          /* function for freeing memory */
 447 #endif
 448 
 449 /* New member added in libpng-1.0.13 and 1.2.0 */
 450    png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
 451 
 452 #ifdef PNG_READ_QUANTIZE_SUPPORTED
 453 /* The following three members were added at version 1.0.14 and 1.2.4 */
 454    png_bytep quantize_sort;          /* working sort array */
 455    png_bytep index_to_palette;       /* where the original index currently is
 456                                         in the palette */
 457    png_bytep palette_to_index;       /* which original index points to this
 458                                          palette color */
 459 #endif
 460 
 461 /* New members added in libpng-1.0.16 and 1.2.6 */
 462    png_byte compression_type;
 463 
 464 #ifdef PNG_USER_LIMITS_SUPPORTED
 465    png_uint_32 user_width_max;
 466    png_uint_32 user_height_max;
 467 
 468    /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
 469     * chunks that can be stored (0 means unlimited).
 470     */
 471    png_uint_32 user_chunk_cache_max;
 472 
 473    /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
 474     * can occupy when decompressed.  0 means unlimited.
 475     */
 476    png_alloc_size_t user_chunk_malloc_max;
 477 #endif
 478 
 479 /* New member added in libpng-1.0.25 and 1.2.17 */
 480 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
 481    /* Temporary storage for unknown chunk that the library doesn't recognize,
 482     * used while reading the chunk.
 483     */
 484    png_unknown_chunk unknown_chunk;
 485 #endif
 486 
 487 /* New member added in libpng-1.2.26 */
 488    size_t old_big_row_buf_size;
 489 
 490 #ifdef PNG_READ_SUPPORTED
 491 /* New member added in libpng-1.2.30 */
 492   png_bytep        read_buffer;      /* buffer for reading chunk data */
 493   png_alloc_size_t read_buffer_size; /* current size of the buffer */
 494 #endif
 495 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 496   uInt             IDAT_read_size;   /* limit on read buffer size for IDAT */
 497 #endif
 498 
 499 #ifdef PNG_IO_STATE_SUPPORTED
 500 /* New member added in libpng-1.4.0 */
 501    png_uint_32 io_state;
 502 #endif
 503 
 504 /* New member added in libpng-1.5.6 */
 505    png_bytep big_prev_row;
 506 
 507 /* New member added in libpng-1.5.7 */
 508    void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
 509       png_bytep row, png_const_bytep prev_row);
 510 
 511 #ifdef PNG_READ_SUPPORTED
 512 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
 513    png_colorspace   colorspace;
 514 #endif
 515 #endif
 516 };
 517 #endif /* PNGSTRUCT_H */
--- EOF ---