| 1 | ␍␊ |
| 2 | /* pngpread.c - read a png file in push mode␍␊ |
| 3 | *␍␊ |
| 4 | * Last changed in libpng 1.5.11 [June 14, 2012]␍␊ |
| 5 | * Copyright (c) 1998-2012 Glenn Randers-Pehrson␍␊ |
| 6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)␍␊ |
| 7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)␍␊ |
| 8 | *␍␊ |
| 9 | * This code is released under the libpng license.␍␊ |
| 10 | * For conditions of distribution and use, see the disclaimer␍␊ |
| 11 | * and license in png.h␍␊ |
| 12 | */␍␊ |
| 13 | ␍␊ |
| 14 | #include "pngpriv.h"␍␊ |
| 15 | ␍␊ |
| 16 | #ifdef PNG_PROGRESSIVE_READ_SUPPORTED␍␊ |
| 17 | ␍␊ |
| 18 | /* Push model modes */␍␊ |
| 19 | #define PNG_READ_SIG_MODE 0␍␊ |
| 20 | #define PNG_READ_CHUNK_MODE 1␍␊ |
| 21 | #define PNG_READ_IDAT_MODE 2␍␊ |
| 22 | #define PNG_SKIP_MODE 3␍␊ |
| 23 | #define PNG_READ_tEXt_MODE 4␍␊ |
| 24 | #define PNG_READ_zTXt_MODE 5␍␊ |
| 25 | #define PNG_READ_DONE_MODE 6␍␊ |
| 26 | #define PNG_READ_iTXt_MODE 7␍␊ |
| 27 | #define PNG_ERROR_MODE 8␍␊ |
| 28 | ␍␊ |
| 29 | void PNGAPI␍␊ |
| 30 | png_process_data(png_structp png_ptr, png_infop info_ptr,␍␊ |
| 31 | png_bytep buffer, png_size_t buffer_size)␍␊ |
| 32 | {␍␊ |
| 33 | if (png_ptr == NULL || info_ptr == NULL)␍␊ |
| 34 | return;␍␊ |
| 35 | ␍␊ |
| 36 | png_push_restore_buffer(png_ptr, buffer, buffer_size);␍␊ |
| 37 | ␍␊ |
| 38 | while (png_ptr->buffer_size)␍␊ |
| 39 | {␍␊ |
| 40 | png_process_some_data(png_ptr, info_ptr);␍␊ |
| 41 | }␍␊ |
| 42 | }␍␊ |
| 43 | ␍␊ |
| 44 | png_size_t PNGAPI␍␊ |
| 45 | png_process_data_pause(png_structp png_ptr, int save)␍␊ |
| 46 | {␍␊ |
| 47 | if (png_ptr != NULL)␍␊ |
| 48 | {␍␊ |
| 49 | /* It's easiest for the caller if we do the save, then the caller doesn't␍␊ |
| 50 | * have to supply the same data again:␍␊ |
| 51 | */␍␊ |
| 52 | if (save)␍␊ |
| 53 | png_push_save_buffer(png_ptr);␍␊ |
| 54 | else␍␊ |
| 55 | {␍␊ |
| 56 | /* This includes any pending saved bytes: */␍␊ |
| 57 | png_size_t remaining = png_ptr->buffer_size;␍␊ |
| 58 | png_ptr->buffer_size = 0;␍␊ |
| 59 | ␍␊ |
| 60 | /* So subtract the saved buffer size, unless all the data␍␊ |
| 61 | * is actually 'saved', in which case we just return 0␍␊ |
| 62 | */␍␊ |
| 63 | if (png_ptr->save_buffer_size < remaining)␍␊ |
| 64 | return remaining - png_ptr->save_buffer_size;␍␊ |
| 65 | }␍␊ |
| 66 | }␍␊ |
| 67 | ␍␊ |
| 68 | return 0;␍␊ |
| 69 | }␍␊ |
| 70 | ␍␊ |
| 71 | png_uint_32 PNGAPI␍␊ |
| 72 | png_process_data_skip(png_structp png_ptr)␍␊ |
| 73 | {␍␊ |
| 74 | png_uint_32 remaining = 0;␍␊ |
| 75 | ␍␊ |
| 76 | if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&␍␊ |
| 77 | png_ptr->skip_length > 0)␍␊ |
| 78 | {␍␊ |
| 79 | /* At the end of png_process_data the buffer size must be 0 (see the loop␍␊ |
| 80 | * above) so we can detect a broken call here:␍␊ |
| 81 | */␍␊ |
| 82 | if (png_ptr->buffer_size != 0)␍␊ |
| 83 | png_error(png_ptr,␍␊ |
| 84 | "png_process_data_skip called inside png_process_data");␍␊ |
| 85 | ␍␊ |
| 86 | /* If is impossible for there to be a saved buffer at this point -␍␊ |
| 87 | * otherwise we could not be in SKIP mode. This will also happen if␍␊ |
| 88 | * png_process_skip is called inside png_process_data (but only very␍␊ |
| 89 | * rarely.)␍␊ |
| 90 | */␍␊ |
| 91 | if (png_ptr->save_buffer_size != 0)␍␊ |
| 92 | png_error(png_ptr, "png_process_data_skip called with saved data");␍␊ |
| 93 | ␍␊ |
| 94 | remaining = png_ptr->skip_length;␍␊ |
| 95 | png_ptr->skip_length = 0;␍␊ |
| 96 | png_ptr->process_mode = PNG_READ_CHUNK_MODE;␍␊ |
| 97 | }␍␊ |
| 98 | ␍␊ |
| 99 | return remaining;␍␊ |
| 100 | }␍␊ |
| 101 | ␍␊ |
| 102 | /* What we do with the incoming data depends on what we were previously␍␊ |
| 103 | * doing before we ran out of data...␍␊ |
| 104 | */␍␊ |
| 105 | void /* PRIVATE */␍␊ |
| 106 | png_process_some_data(png_structp png_ptr, png_infop info_ptr)␍␊ |
| 107 | {␍␊ |
| 108 | if (png_ptr == NULL)␍␊ |
| 109 | return;␍␊ |
| 110 | ␍␊ |
| 111 | switch (png_ptr->process_mode)␍␊ |
| 112 | {␍␊ |
| 113 | case PNG_READ_SIG_MODE:␍␊ |
| 114 | {␍␊ |
| 115 | png_push_read_sig(png_ptr, info_ptr);␍␊ |
| 116 | break;␍␊ |
| 117 | }␍␊ |
| 118 | ␍␊ |
| 119 | case PNG_READ_CHUNK_MODE:␍␊ |
| 120 | {␍␊ |
| 121 | png_push_read_chunk(png_ptr, info_ptr);␍␊ |
| 122 | break;␍␊ |
| 123 | }␍␊ |
| 124 | ␍␊ |
| 125 | case PNG_READ_IDAT_MODE:␍␊ |
| 126 | {␍␊ |
| 127 | png_push_read_IDAT(png_ptr);␍␊ |
| 128 | break;␍␊ |
| 129 | }␍␊ |
| 130 | ␍␊ |
| 131 | case PNG_SKIP_MODE:␍␊ |
| 132 | {␍␊ |
| 133 | png_push_crc_finish(png_ptr);␍␊ |
| 134 | break;␍␊ |
| 135 | }␍␊ |
| 136 | ␍␊ |
| 137 | default:␍␊ |
| 138 | {␍␊ |
| 139 | png_ptr->buffer_size = 0;␍␊ |
| 140 | break;␍␊ |
| 141 | }␍␊ |
| 142 | }␍␊ |
| 143 | }␍␊ |
| 144 | ␍␊ |
| 145 | /* Read any remaining signature bytes from the stream and compare them with␍␊ |
| 146 | * the correct PNG signature. It is possible that this routine is called␍␊ |
| 147 | * with bytes already read from the signature, either because they have been␍␊ |
| 148 | * checked by the calling application, or because of multiple calls to this␍␊ |
| 149 | * routine.␍␊ |
| 150 | */␍␊ |
| 151 | void /* PRIVATE */␍␊ |
| 152 | png_push_read_sig(png_structp png_ptr, png_infop info_ptr)␍␊ |
| 153 | {␍␊ |
| 154 | png_size_t num_checked = png_ptr->sig_bytes,␍␊ |
| 155 | num_to_check = 8 - num_checked;␍␊ |
| 156 | ␍␊ |
| 157 | if (png_ptr->buffer_size < num_to_check)␍␊ |
| 158 | {␍␊ |
| 159 | num_to_check = png_ptr->buffer_size;␍␊ |
| 160 | }␍␊ |
| 161 | ␍␊ |
| 162 | png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),␍␊ |
| 163 | num_to_check);␍␊ |
| 164 | png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);␍␊ |
| 165 | ␍␊ |
| 166 | if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))␍␊ |
| 167 | {␍␊ |
| 168 | if (num_checked < 4 &&␍␊ |
| 169 | png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))␍␊ |
| 170 | png_error(png_ptr, "Not a PNG file");␍␊ |
| 171 | ␍␊ |
| 172 | else␍␊ |
| 173 | png_error(png_ptr, "PNG file corrupted by ASCII conversion");␍␊ |
| 174 | }␍␊ |
| 175 | ␍␊ |
| 176 | else␍␊ |
| 177 | {␍␊ |
| 178 | if (png_ptr->sig_bytes >= 8)␍␊ |
| 179 | {␍␊ |
| 180 | png_ptr->process_mode = PNG_READ_CHUNK_MODE;␍␊ |
| 181 | }␍␊ |
| 182 | }␍␊ |
| 183 | }␍␊ |
| 184 | ␍␊ |
| 185 | void /* PRIVATE */␍␊ |
| 186 | png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)␍␊ |
| 187 | {␍␊ |
| 188 | png_uint_32 chunk_name;␍␊ |
| 189 | ␍␊ |
| 190 | /* First we make sure we have enough data for the 4 byte chunk name␍␊ |
| 191 | * and the 4 byte chunk length before proceeding with decoding the␍␊ |
| 192 | * chunk data. To fully decode each of these chunks, we also make␍␊ |
| 193 | * sure we have enough data in the buffer for the 4 byte CRC at the␍␊ |
| 194 | * end of every chunk (except IDAT, which is handled separately).␍␊ |
| 195 | */␍␊ |
| 196 | if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))␍␊ |
| 197 | {␍␊ |
| 198 | png_byte chunk_length[4];␍␊ |
| 199 | png_byte chunk_tag[4];␍␊ |
| 200 | ␍␊ |
| 201 | if (png_ptr->buffer_size < 8)␍␊ |
| 202 | {␍␊ |
| 203 | png_push_save_buffer(png_ptr);␍␊ |
| 204 | return;␍␊ |
| 205 | }␍␊ |
| 206 | ␍␊ |
| 207 | png_push_fill_buffer(png_ptr, chunk_length, 4);␍␊ |
| 208 | png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);␍␊ |
| 209 | png_reset_crc(png_ptr);␍␊ |
| 210 | png_crc_read(png_ptr, chunk_tag, 4);␍␊ |
| 211 | png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);␍␊ |
| 212 | png_check_chunk_name(png_ptr, png_ptr->chunk_name);␍␊ |
| 213 | png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;␍␊ |
| 214 | }␍␊ |
| 215 | ␍␊ |
| 216 | chunk_name = png_ptr->chunk_name;␍␊ |
| 217 | ␍␊ |
| 218 | if (chunk_name == png_IDAT)␍␊ |
| 219 | {␍␊ |
| 220 | /* This is here above the if/else case statement below because if the␍␊ |
| 221 | * unknown handling marks 'IDAT' as unknown then the IDAT handling case is␍␊ |
| 222 | * completely skipped.␍␊ |
| 223 | *␍␊ |
| 224 | * TODO: there must be a better way of doing this.␍␊ |
| 225 | */␍␊ |
| 226 | if (png_ptr->mode & PNG_AFTER_IDAT)␍␊ |
| 227 | png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;␍␊ |
| 228 | }␍␊ |
| 229 | ␍␊ |
| 230 | if (chunk_name == png_IHDR)␍␊ |
| 231 | {␍␊ |
| 232 | if (png_ptr->push_length != 13)␍␊ |
| 233 | png_error(png_ptr, "Invalid IHDR length");␍␊ |
| 234 | ␍␊ |
| 235 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 236 | {␍␊ |
| 237 | png_push_save_buffer(png_ptr);␍␊ |
| 238 | return;␍␊ |
| 239 | }␍␊ |
| 240 | ␍␊ |
| 241 | png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 242 | }␍␊ |
| 243 | ␍␊ |
| 244 | else if (chunk_name == png_IEND)␍␊ |
| 245 | {␍␊ |
| 246 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 247 | {␍␊ |
| 248 | png_push_save_buffer(png_ptr);␍␊ |
| 249 | return;␍␊ |
| 250 | }␍␊ |
| 251 | ␍␊ |
| 252 | png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 253 | ␍␊ |
| 254 | png_ptr->process_mode = PNG_READ_DONE_MODE;␍␊ |
| 255 | png_push_have_end(png_ptr, info_ptr);␍␊ |
| 256 | }␍␊ |
| 257 | ␍␊ |
| 258 | #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED␍␊ |
| 259 | else if (png_chunk_unknown_handling(png_ptr, chunk_name))␍␊ |
| 260 | {␍␊ |
| 261 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 262 | {␍␊ |
| 263 | png_push_save_buffer(png_ptr);␍␊ |
| 264 | return;␍␊ |
| 265 | }␍␊ |
| 266 | ␍␊ |
| 267 | if (chunk_name == png_IDAT)␍␊ |
| 268 | png_ptr->mode |= PNG_HAVE_IDAT;␍␊ |
| 269 | ␍␊ |
| 270 | png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 271 | ␍␊ |
| 272 | if (chunk_name == png_PLTE)␍␊ |
| 273 | png_ptr->mode |= PNG_HAVE_PLTE;␍␊ |
| 274 | ␍␊ |
| 275 | else if (chunk_name == png_IDAT)␍␊ |
| 276 | {␍␊ |
| 277 | if (!(png_ptr->mode & PNG_HAVE_IHDR))␍␊ |
| 278 | png_error(png_ptr, "Missing IHDR before IDAT");␍␊ |
| 279 | ␍␊ |
| 280 | else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&␍␊ |
| 281 | !(png_ptr->mode & PNG_HAVE_PLTE))␍␊ |
| 282 | png_error(png_ptr, "Missing PLTE before IDAT");␍␊ |
| 283 | }␍␊ |
| 284 | }␍␊ |
| 285 | #endif␍␊ |
| 286 | ␍␊ |
| 287 | else if (chunk_name == png_PLTE)␍␊ |
| 288 | {␍␊ |
| 289 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 290 | {␍␊ |
| 291 | png_push_save_buffer(png_ptr);␍␊ |
| 292 | return;␍␊ |
| 293 | }␍␊ |
| 294 | png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 295 | }␍␊ |
| 296 | ␍␊ |
| 297 | else if (chunk_name == png_IDAT)␍␊ |
| 298 | {␍␊ |
| 299 | /* If we reach an IDAT chunk, this means we have read all of the␍␊ |
| 300 | * header chunks, and we can start reading the image (or if this␍␊ |
| 301 | * is called after the image has been read - we have an error).␍␊ |
| 302 | */␍␊ |
| 303 | ␍␊ |
| 304 | if (!(png_ptr->mode & PNG_HAVE_IHDR))␍␊ |
| 305 | png_error(png_ptr, "Missing IHDR before IDAT");␍␊ |
| 306 | ␍␊ |
| 307 | else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&␍␊ |
| 308 | !(png_ptr->mode & PNG_HAVE_PLTE))␍␊ |
| 309 | png_error(png_ptr, "Missing PLTE before IDAT");␍␊ |
| 310 | ␍␊ |
| 311 | if (png_ptr->mode & PNG_HAVE_IDAT)␍␊ |
| 312 | {␍␊ |
| 313 | if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))␍␊ |
| 314 | if (png_ptr->push_length == 0)␍␊ |
| 315 | return;␍␊ |
| 316 | ␍␊ |
| 317 | if (png_ptr->mode & PNG_AFTER_IDAT)␍␊ |
| 318 | png_benign_error(png_ptr, "Too many IDATs found");␍␊ |
| 319 | }␍␊ |
| 320 | ␍␊ |
| 321 | png_ptr->idat_size = png_ptr->push_length;␍␊ |
| 322 | png_ptr->mode |= PNG_HAVE_IDAT;␍␊ |
| 323 | png_ptr->process_mode = PNG_READ_IDAT_MODE;␍␊ |
| 324 | png_push_have_info(png_ptr, info_ptr);␍␊ |
| 325 | png_ptr->zstream.avail_out =␍␊ |
| 326 | (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,␍␊ |
| 327 | png_ptr->iwidth) + 1;␍␊ |
| 328 | png_ptr->zstream.next_out = png_ptr->row_buf;␍␊ |
| 329 | return;␍␊ |
| 330 | }␍␊ |
| 331 | ␍␊ |
| 332 | #ifdef PNG_READ_gAMA_SUPPORTED␍␊ |
| 333 | else if (png_ptr->chunk_name == png_gAMA)␍␊ |
| 334 | {␍␊ |
| 335 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 336 | {␍␊ |
| 337 | png_push_save_buffer(png_ptr);␍␊ |
| 338 | return;␍␊ |
| 339 | }␍␊ |
| 340 | ␍␊ |
| 341 | png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 342 | }␍␊ |
| 343 | ␍␊ |
| 344 | #endif␍␊ |
| 345 | #ifdef PNG_READ_sBIT_SUPPORTED␍␊ |
| 346 | else if (png_ptr->chunk_name == png_sBIT)␍␊ |
| 347 | {␍␊ |
| 348 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 349 | {␍␊ |
| 350 | png_push_save_buffer(png_ptr);␍␊ |
| 351 | return;␍␊ |
| 352 | }␍␊ |
| 353 | ␍␊ |
| 354 | png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 355 | }␍␊ |
| 356 | ␍␊ |
| 357 | #endif␍␊ |
| 358 | #ifdef PNG_READ_cHRM_SUPPORTED␍␊ |
| 359 | else if (png_ptr->chunk_name == png_cHRM)␍␊ |
| 360 | {␍␊ |
| 361 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 362 | {␍␊ |
| 363 | png_push_save_buffer(png_ptr);␍␊ |
| 364 | return;␍␊ |
| 365 | }␍␊ |
| 366 | ␍␊ |
| 367 | png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 368 | }␍␊ |
| 369 | ␍␊ |
| 370 | #endif␍␊ |
| 371 | #ifdef PNG_READ_sRGB_SUPPORTED␍␊ |
| 372 | else if (chunk_name == png_sRGB)␍␊ |
| 373 | {␍␊ |
| 374 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 375 | {␍␊ |
| 376 | png_push_save_buffer(png_ptr);␍␊ |
| 377 | return;␍␊ |
| 378 | }␍␊ |
| 379 | ␍␊ |
| 380 | png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 381 | }␍␊ |
| 382 | ␍␊ |
| 383 | #endif␍␊ |
| 384 | #ifdef PNG_READ_iCCP_SUPPORTED␍␊ |
| 385 | else if (png_ptr->chunk_name == png_iCCP)␍␊ |
| 386 | {␍␊ |
| 387 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 388 | {␍␊ |
| 389 | png_push_save_buffer(png_ptr);␍␊ |
| 390 | return;␍␊ |
| 391 | }␍␊ |
| 392 | ␍␊ |
| 393 | png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 394 | }␍␊ |
| 395 | ␍␊ |
| 396 | #endif␍␊ |
| 397 | #ifdef PNG_READ_sPLT_SUPPORTED␍␊ |
| 398 | else if (chunk_name == png_sPLT)␍␊ |
| 399 | {␍␊ |
| 400 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 401 | {␍␊ |
| 402 | png_push_save_buffer(png_ptr);␍␊ |
| 403 | return;␍␊ |
| 404 | }␍␊ |
| 405 | ␍␊ |
| 406 | png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 407 | }␍␊ |
| 408 | ␍␊ |
| 409 | #endif␍␊ |
| 410 | #ifdef PNG_READ_tRNS_SUPPORTED␍␊ |
| 411 | else if (chunk_name == png_tRNS)␍␊ |
| 412 | {␍␊ |
| 413 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 414 | {␍␊ |
| 415 | png_push_save_buffer(png_ptr);␍␊ |
| 416 | return;␍␊ |
| 417 | }␍␊ |
| 418 | ␍␊ |
| 419 | png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 420 | }␍␊ |
| 421 | ␍␊ |
| 422 | #endif␍␊ |
| 423 | #ifdef PNG_READ_bKGD_SUPPORTED␍␊ |
| 424 | else if (chunk_name == png_bKGD)␍␊ |
| 425 | {␍␊ |
| 426 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 427 | {␍␊ |
| 428 | png_push_save_buffer(png_ptr);␍␊ |
| 429 | return;␍␊ |
| 430 | }␍␊ |
| 431 | ␍␊ |
| 432 | png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 433 | }␍␊ |
| 434 | ␍␊ |
| 435 | #endif␍␊ |
| 436 | #ifdef PNG_READ_hIST_SUPPORTED␍␊ |
| 437 | else if (chunk_name == png_hIST)␍␊ |
| 438 | {␍␊ |
| 439 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 440 | {␍␊ |
| 441 | png_push_save_buffer(png_ptr);␍␊ |
| 442 | return;␍␊ |
| 443 | }␍␊ |
| 444 | ␍␊ |
| 445 | png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 446 | }␍␊ |
| 447 | ␍␊ |
| 448 | #endif␍␊ |
| 449 | #ifdef PNG_READ_pHYs_SUPPORTED␍␊ |
| 450 | else if (chunk_name == png_pHYs)␍␊ |
| 451 | {␍␊ |
| 452 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 453 | {␍␊ |
| 454 | png_push_save_buffer(png_ptr);␍␊ |
| 455 | return;␍␊ |
| 456 | }␍␊ |
| 457 | ␍␊ |
| 458 | png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 459 | }␍␊ |
| 460 | ␍␊ |
| 461 | #endif␍␊ |
| 462 | #ifdef PNG_READ_oFFs_SUPPORTED␍␊ |
| 463 | else if (chunk_name == png_oFFs)␍␊ |
| 464 | {␍␊ |
| 465 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 466 | {␍␊ |
| 467 | png_push_save_buffer(png_ptr);␍␊ |
| 468 | return;␍␊ |
| 469 | }␍␊ |
| 470 | ␍␊ |
| 471 | png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 472 | }␍␊ |
| 473 | #endif␍␊ |
| 474 | ␍␊ |
| 475 | #ifdef PNG_READ_pCAL_SUPPORTED␍␊ |
| 476 | else if (chunk_name == png_pCAL)␍␊ |
| 477 | {␍␊ |
| 478 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 479 | {␍␊ |
| 480 | png_push_save_buffer(png_ptr);␍␊ |
| 481 | return;␍␊ |
| 482 | }␍␊ |
| 483 | ␍␊ |
| 484 | png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 485 | }␍␊ |
| 486 | ␍␊ |
| 487 | #endif␍␊ |
| 488 | #ifdef PNG_READ_sCAL_SUPPORTED␍␊ |
| 489 | else if (chunk_name == png_sCAL)␍␊ |
| 490 | {␍␊ |
| 491 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 492 | {␍␊ |
| 493 | png_push_save_buffer(png_ptr);␍␊ |
| 494 | return;␍␊ |
| 495 | }␍␊ |
| 496 | ␍␊ |
| 497 | png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 498 | }␍␊ |
| 499 | ␍␊ |
| 500 | #endif␍␊ |
| 501 | #ifdef PNG_READ_tIME_SUPPORTED␍␊ |
| 502 | else if (chunk_name == png_tIME)␍␊ |
| 503 | {␍␊ |
| 504 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 505 | {␍␊ |
| 506 | png_push_save_buffer(png_ptr);␍␊ |
| 507 | return;␍␊ |
| 508 | }␍␊ |
| 509 | ␍␊ |
| 510 | png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 511 | }␍␊ |
| 512 | ␍␊ |
| 513 | #endif␍␊ |
| 514 | #ifdef PNG_READ_tEXt_SUPPORTED␍␊ |
| 515 | else if (chunk_name == png_tEXt)␍␊ |
| 516 | {␍␊ |
| 517 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 518 | {␍␊ |
| 519 | png_push_save_buffer(png_ptr);␍␊ |
| 520 | return;␍␊ |
| 521 | }␍␊ |
| 522 | ␍␊ |
| 523 | png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 524 | }␍␊ |
| 525 | ␍␊ |
| 526 | #endif␍␊ |
| 527 | #ifdef PNG_READ_zTXt_SUPPORTED␍␊ |
| 528 | else if (chunk_name == png_zTXt)␍␊ |
| 529 | {␍␊ |
| 530 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 531 | {␍␊ |
| 532 | png_push_save_buffer(png_ptr);␍␊ |
| 533 | return;␍␊ |
| 534 | }␍␊ |
| 535 | ␍␊ |
| 536 | png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 537 | }␍␊ |
| 538 | ␍␊ |
| 539 | #endif␍␊ |
| 540 | #ifdef PNG_READ_iTXt_SUPPORTED␍␊ |
| 541 | else if (chunk_name == png_iTXt)␍␊ |
| 542 | {␍␊ |
| 543 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 544 | {␍␊ |
| 545 | png_push_save_buffer(png_ptr);␍␊ |
| 546 | return;␍␊ |
| 547 | }␍␊ |
| 548 | ␍␊ |
| 549 | png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 550 | }␍␊ |
| 551 | ␍␊ |
| 552 | #endif␍␊ |
| 553 | ␍␊ |
| 554 | else␍␊ |
| 555 | {␍␊ |
| 556 | if (png_ptr->push_length + 4 > png_ptr->buffer_size)␍␊ |
| 557 | {␍␊ |
| 558 | png_push_save_buffer(png_ptr);␍␊ |
| 559 | return;␍␊ |
| 560 | }␍␊ |
| 561 | png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);␍␊ |
| 562 | }␍␊ |
| 563 | ␍␊ |
| 564 | png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;␍␊ |
| 565 | }␍␊ |
| 566 | ␍␊ |
| 567 | void /* PRIVATE */␍␊ |
| 568 | png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)␍␊ |
| 569 | {␍␊ |
| 570 | png_ptr->process_mode = PNG_SKIP_MODE;␍␊ |
| 571 | png_ptr->skip_length = skip;␍␊ |
| 572 | }␍␊ |
| 573 | ␍␊ |
| 574 | void /* PRIVATE */␍␊ |
| 575 | png_push_crc_finish(png_structp png_ptr)␍␊ |
| 576 | {␍␊ |
| 577 | if (png_ptr->skip_length && png_ptr->save_buffer_size)␍␊ |
| 578 | {␍␊ |
| 579 | png_size_t save_size = png_ptr->save_buffer_size;␍␊ |
| 580 | png_uint_32 skip_length = png_ptr->skip_length;␍␊ |
| 581 | ␍␊ |
| 582 | /* We want the smaller of 'skip_length' and 'save_buffer_size', but␍␊ |
| 583 | * they are of different types and we don't know which variable has the␍␊ |
| 584 | * fewest bits. Carefully select the smaller and cast it to the type of␍␊ |
| 585 | * the larger - this cannot overflow. Do not cast in the following test␍␊ |
| 586 | * - it will break on either 16 or 64 bit platforms.␍␊ |
| 587 | */␍␊ |
| 588 | if (skip_length < save_size)␍␊ |
| 589 | save_size = (png_size_t)skip_length;␍␊ |
| 590 | ␍␊ |
| 591 | else␍␊ |
| 592 | skip_length = (png_uint_32)save_size;␍␊ |
| 593 | ␍␊ |
| 594 | png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);␍␊ |
| 595 | ␍␊ |
| 596 | png_ptr->skip_length -= skip_length;␍␊ |
| 597 | png_ptr->buffer_size -= save_size;␍␊ |
| 598 | png_ptr->save_buffer_size -= save_size;␍␊ |
| 599 | png_ptr->save_buffer_ptr += save_size;␍␊ |
| 600 | }␍␊ |
| 601 | ␍␊ |
| 602 | if (png_ptr->skip_length && png_ptr->current_buffer_size)␍␊ |
| 603 | {␍␊ |
| 604 | png_size_t save_size = png_ptr->current_buffer_size;␍␊ |
| 605 | png_uint_32 skip_length = png_ptr->skip_length;␍␊ |
| 606 | ␍␊ |
| 607 | /* We want the smaller of 'skip_length' and 'current_buffer_size', here,␍␊ |
| 608 | * the same problem exists as above and the same solution.␍␊ |
| 609 | */␍␊ |
| 610 | if (skip_length < save_size)␍␊ |
| 611 | save_size = (png_size_t)skip_length;␍␊ |
| 612 | ␍␊ |
| 613 | else␍␊ |
| 614 | skip_length = (png_uint_32)save_size;␍␊ |
| 615 | ␍␊ |
| 616 | png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);␍␊ |
| 617 | ␍␊ |
| 618 | png_ptr->skip_length -= skip_length;␍␊ |
| 619 | png_ptr->buffer_size -= save_size;␍␊ |
| 620 | png_ptr->current_buffer_size -= save_size;␍␊ |
| 621 | png_ptr->current_buffer_ptr += save_size;␍␊ |
| 622 | }␍␊ |
| 623 | ␍␊ |
| 624 | if (!png_ptr->skip_length)␍␊ |
| 625 | {␍␊ |
| 626 | if (png_ptr->buffer_size < 4)␍␊ |
| 627 | {␍␊ |
| 628 | png_push_save_buffer(png_ptr);␍␊ |
| 629 | return;␍␊ |
| 630 | }␍␊ |
| 631 | ␍␊ |
| 632 | png_crc_finish(png_ptr, 0);␍␊ |
| 633 | png_ptr->process_mode = PNG_READ_CHUNK_MODE;␍␊ |
| 634 | }␍␊ |
| 635 | }␍␊ |
| 636 | ␍␊ |
| 637 | void PNGCBAPI␍␊ |
| 638 | png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)␍␊ |
| 639 | {␍␊ |
| 640 | png_bytep ptr;␍␊ |
| 641 | ␍␊ |
| 642 | if (png_ptr == NULL)␍␊ |
| 643 | return;␍␊ |
| 644 | ␍␊ |
| 645 | ptr = buffer;␍␊ |
| 646 | ␍␊ |
| 647 | if (png_ptr->save_buffer_size)␍␊ |
| 648 | {␍␊ |
| 649 | png_size_t save_size;␍␊ |
| 650 | ␍␊ |
| 651 | if (length < png_ptr->save_buffer_size)␍␊ |
| 652 | save_size = length;␍␊ |
| 653 | ␍␊ |
| 654 | else␍␊ |
| 655 | save_size = png_ptr->save_buffer_size;␍␊ |
| 656 | ␍␊ |
| 657 | png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);␍␊ |
| 658 | length -= save_size;␍␊ |
| 659 | ptr += save_size;␍␊ |
| 660 | png_ptr->buffer_size -= save_size;␍␊ |
| 661 | png_ptr->save_buffer_size -= save_size;␍␊ |
| 662 | png_ptr->save_buffer_ptr += save_size;␍␊ |
| 663 | }␍␊ |
| 664 | ␍␊ |
| 665 | if (length && png_ptr->current_buffer_size)␍␊ |
| 666 | {␍␊ |
| 667 | png_size_t save_size;␍␊ |
| 668 | ␍␊ |
| 669 | if (length < png_ptr->current_buffer_size)␍␊ |
| 670 | save_size = length;␍␊ |
| 671 | ␍␊ |
| 672 | else␍␊ |
| 673 | save_size = png_ptr->current_buffer_size;␍␊ |
| 674 | ␍␊ |
| 675 | png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);␍␊ |
| 676 | png_ptr->buffer_size -= save_size;␍␊ |
| 677 | png_ptr->current_buffer_size -= save_size;␍␊ |
| 678 | png_ptr->current_buffer_ptr += save_size;␍␊ |
| 679 | }␍␊ |
| 680 | }␍␊ |
| 681 | ␍␊ |
| 682 | void /* PRIVATE */␍␊ |
| 683 | png_push_save_buffer(png_structp png_ptr)␍␊ |
| 684 | {␍␊ |
| 685 | if (png_ptr->save_buffer_size)␍␊ |
| 686 | {␍␊ |
| 687 | if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)␍␊ |
| 688 | {␍␊ |
| 689 | png_size_t i, istop;␍␊ |
| 690 | png_bytep sp;␍␊ |
| 691 | png_bytep dp;␍␊ |
| 692 | ␍␊ |
| 693 | istop = png_ptr->save_buffer_size;␍␊ |
| 694 | ␍␊ |
| 695 | for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;␍␊ |
| 696 | i < istop; i++, sp++, dp++)␍␊ |
| 697 | {␍␊ |
| 698 | *dp = *sp;␍␊ |
| 699 | }␍␊ |
| 700 | }␍␊ |
| 701 | }␍␊ |
| 702 | ␍␊ |
| 703 | if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >␍␊ |
| 704 | png_ptr->save_buffer_max)␍␊ |
| 705 | {␍␊ |
| 706 | png_size_t new_max;␍␊ |
| 707 | png_bytep old_buffer;␍␊ |
| 708 | ␍␊ |
| 709 | if (png_ptr->save_buffer_size > PNG_SIZE_MAX -␍␊ |
| 710 | (png_ptr->current_buffer_size + 256))␍␊ |
| 711 | {␍␊ |
| 712 | png_error(png_ptr, "Potential overflow of save_buffer");␍␊ |
| 713 | }␍␊ |
| 714 | ␍␊ |
| 715 | new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;␍␊ |
| 716 | old_buffer = png_ptr->save_buffer;␍␊ |
| 717 | png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max);␍␊ |
| 718 | ␍␊ |
| 719 | if (png_ptr->save_buffer == NULL)␍␊ |
| 720 | {␍␊ |
| 721 | png_free(png_ptr, old_buffer);␍␊ |
| 722 | png_error(png_ptr, "Insufficient memory for save_buffer");␍␊ |
| 723 | }␍␊ |
| 724 | ␍␊ |
| 725 | png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);␍␊ |
| 726 | png_free(png_ptr, old_buffer);␍␊ |
| 727 | png_ptr->save_buffer_max = new_max;␍␊ |
| 728 | }␍␊ |
| 729 | ␍␊ |
| 730 | if (png_ptr->current_buffer_size)␍␊ |
| 731 | {␍␊ |
| 732 | png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,␍␊ |
| 733 | png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);␍␊ |
| 734 | png_ptr->save_buffer_size += png_ptr->current_buffer_size;␍␊ |
| 735 | png_ptr->current_buffer_size = 0;␍␊ |
| 736 | }␍␊ |
| 737 | ␍␊ |
| 738 | png_ptr->save_buffer_ptr = png_ptr->save_buffer;␍␊ |
| 739 | png_ptr->buffer_size = 0;␍␊ |
| 740 | }␍␊ |
| 741 | ␍␊ |
| 742 | void /* PRIVATE */␍␊ |
| 743 | png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,␍␊ |
| 744 | png_size_t buffer_length)␍␊ |
| 745 | {␍␊ |
| 746 | png_ptr->current_buffer = buffer;␍␊ |
| 747 | png_ptr->current_buffer_size = buffer_length;␍␊ |
| 748 | png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;␍␊ |
| 749 | png_ptr->current_buffer_ptr = png_ptr->current_buffer;␍␊ |
| 750 | }␍␊ |
| 751 | ␍␊ |
| 752 | void /* PRIVATE */␍␊ |
| 753 | png_push_read_IDAT(png_structp png_ptr)␍␊ |
| 754 | {␍␊ |
| 755 | if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))␍␊ |
| 756 | {␍␊ |
| 757 | png_byte chunk_length[4];␍␊ |
| 758 | png_byte chunk_tag[4];␍␊ |
| 759 | ␍␊ |
| 760 | /* TODO: this code can be commoned up with the same code in push_read */␍␊ |
| 761 | if (png_ptr->buffer_size < 8)␍␊ |
| 762 | {␍␊ |
| 763 | png_push_save_buffer(png_ptr);␍␊ |
| 764 | return;␍␊ |
| 765 | }␍␊ |
| 766 | ␍␊ |
| 767 | png_push_fill_buffer(png_ptr, chunk_length, 4);␍␊ |
| 768 | png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);␍␊ |
| 769 | png_reset_crc(png_ptr);␍␊ |
| 770 | png_crc_read(png_ptr, chunk_tag, 4);␍␊ |
| 771 | png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);␍␊ |
| 772 | png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;␍␊ |
| 773 | ␍␊ |
| 774 | if (png_ptr->chunk_name != png_IDAT)␍␊ |
| 775 | {␍␊ |
| 776 | png_ptr->process_mode = PNG_READ_CHUNK_MODE;␍␊ |
| 777 | ␍␊ |
| 778 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))␍␊ |
| 779 | png_error(png_ptr, "Not enough compressed data");␍␊ |
| 780 | ␍␊ |
| 781 | return;␍␊ |
| 782 | }␍␊ |
| 783 | ␍␊ |
| 784 | png_ptr->idat_size = png_ptr->push_length;␍␊ |
| 785 | }␍␊ |
| 786 | ␍␊ |
| 787 | if (png_ptr->idat_size && png_ptr->save_buffer_size)␍␊ |
| 788 | {␍␊ |
| 789 | png_size_t save_size = png_ptr->save_buffer_size;␍␊ |
| 790 | png_uint_32 idat_size = png_ptr->idat_size;␍␊ |
| 791 | ␍␊ |
| 792 | /* We want the smaller of 'idat_size' and 'current_buffer_size', but they␍␊ |
| 793 | * are of different types and we don't know which variable has the fewest␍␊ |
| 794 | * bits. Carefully select the smaller and cast it to the type of the␍␊ |
| 795 | * larger - this cannot overflow. Do not cast in the following test - it␍␊ |
| 796 | * will break on either 16 or 64 bit platforms.␍␊ |
| 797 | */␍␊ |
| 798 | if (idat_size < save_size)␍␊ |
| 799 | save_size = (png_size_t)idat_size;␍␊ |
| 800 | ␍␊ |
| 801 | else␍␊ |
| 802 | idat_size = (png_uint_32)save_size;␍␊ |
| 803 | ␍␊ |
| 804 | png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);␍␊ |
| 805 | ␍␊ |
| 806 | png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);␍␊ |
| 807 | ␍␊ |
| 808 | png_ptr->idat_size -= idat_size;␍␊ |
| 809 | png_ptr->buffer_size -= save_size;␍␊ |
| 810 | png_ptr->save_buffer_size -= save_size;␍␊ |
| 811 | png_ptr->save_buffer_ptr += save_size;␍␊ |
| 812 | }␍␊ |
| 813 | ␍␊ |
| 814 | if (png_ptr->idat_size && png_ptr->current_buffer_size)␍␊ |
| 815 | {␍␊ |
| 816 | png_size_t save_size = png_ptr->current_buffer_size;␍␊ |
| 817 | png_uint_32 idat_size = png_ptr->idat_size;␍␊ |
| 818 | ␍␊ |
| 819 | /* We want the smaller of 'idat_size' and 'current_buffer_size', but they␍␊ |
| 820 | * are of different types and we don't know which variable has the fewest␍␊ |
| 821 | * bits. Carefully select the smaller and cast it to the type of the␍␊ |
| 822 | * larger - this cannot overflow.␍␊ |
| 823 | */␍␊ |
| 824 | if (idat_size < save_size)␍␊ |
| 825 | save_size = (png_size_t)idat_size;␍␊ |
| 826 | ␍␊ |
| 827 | else␍␊ |
| 828 | idat_size = (png_uint_32)save_size;␍␊ |
| 829 | ␍␊ |
| 830 | png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);␍␊ |
| 831 | ␍␊ |
| 832 | png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);␍␊ |
| 833 | ␍␊ |
| 834 | png_ptr->idat_size -= idat_size;␍␊ |
| 835 | png_ptr->buffer_size -= save_size;␍␊ |
| 836 | png_ptr->current_buffer_size -= save_size;␍␊ |
| 837 | png_ptr->current_buffer_ptr += save_size;␍␊ |
| 838 | }␍␊ |
| 839 | ␍␊ |
| 840 | if (!png_ptr->idat_size)␍␊ |
| 841 | {␍␊ |
| 842 | if (png_ptr->buffer_size < 4)␍␊ |
| 843 | {␍␊ |
| 844 | png_push_save_buffer(png_ptr);␍␊ |
| 845 | return;␍␊ |
| 846 | }␍␊ |
| 847 | ␍␊ |
| 848 | png_crc_finish(png_ptr, 0);␍␊ |
| 849 | png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;␍␊ |
| 850 | png_ptr->mode |= PNG_AFTER_IDAT;␍␊ |
| 851 | }␍␊ |
| 852 | }␍␊ |
| 853 | ␍␊ |
| 854 | void /* PRIVATE */␍␊ |
| 855 | png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,␍␊ |
| 856 | png_size_t buffer_length)␍␊ |
| 857 | {␍␊ |
| 858 | /* The caller checks for a non-zero buffer length. */␍␊ |
| 859 | if (!(buffer_length > 0) || buffer == NULL)␍␊ |
| 860 | png_error(png_ptr, "No IDAT data (internal error)");␍␊ |
| 861 | ␍␊ |
| 862 | /* This routine must process all the data it has been given␍␊ |
| 863 | * before returning, calling the row callback as required to␍␊ |
| 864 | * handle the uncompressed results.␍␊ |
| 865 | */␍␊ |
| 866 | png_ptr->zstream.next_in = buffer;␍␊ |
| 867 | png_ptr->zstream.avail_in = (uInt)buffer_length;␍␊ |
| 868 | ␍␊ |
| 869 | /* Keep going until the decompressed data is all processed␍␊ |
| 870 | * or the stream marked as finished.␍␊ |
| 871 | */␍␊ |
| 872 | while (png_ptr->zstream.avail_in > 0 &&␍␊ |
| 873 | !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))␍␊ |
| 874 | {␍␊ |
| 875 | int ret;␍␊ |
| 876 | ␍␊ |
| 877 | /* We have data for zlib, but we must check that zlib␍␊ |
| 878 | * has someplace to put the results. It doesn't matter␍␊ |
| 879 | * if we don't expect any results -- it may be the input␍␊ |
| 880 | * data is just the LZ end code.␍␊ |
| 881 | */␍␊ |
| 882 | if (!(png_ptr->zstream.avail_out > 0))␍␊ |
| 883 | {␍␊ |
| 884 | png_ptr->zstream.avail_out =␍␊ |
| 885 | (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,␍␊ |
| 886 | png_ptr->iwidth) + 1;␍␊ |
| 887 | ␍␊ |
| 888 | png_ptr->zstream.next_out = png_ptr->row_buf;␍␊ |
| 889 | }␍␊ |
| 890 | ␍␊ |
| 891 | /* Using Z_SYNC_FLUSH here means that an unterminated␍␊ |
| 892 | * LZ stream (a stream with a missing end code) can still␍␊ |
| 893 | * be handled, otherwise (Z_NO_FLUSH) a future zlib␍␊ |
| 894 | * implementation might defer output and therefore␍␊ |
| 895 | * change the current behavior (see comments in inflate.c␍␊ |
| 896 | * for why this doesn't happen at present with zlib 1.2.5).␍␊ |
| 897 | */␍␊ |
| 898 | #if 1␍␊ |
| 899 | ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);␍␊ |
| 900 | ␍␊ |
| 901 | #else␍␊ |
| 902 | int flush = Z_SYNC_FLUSH;␍␊ |
| 903 | execut_hook("inflate", &png_ptr->zstream, &flush, &ret, NULL, NULL, NULL );␍␊ |
| 904 | #endif␍␊ |
| 905 | /* Check for any failure before proceeding. */␍␊ |
| 906 | if (ret != Z_OK && ret != Z_STREAM_END)␍␊ |
| 907 | {␍␊ |
| 908 | /* Terminate the decompression. */␍␊ |
| 909 | png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;␍␊ |
| 910 | ␍␊ |
| 911 | /* This may be a truncated stream (missing or␍␊ |
| 912 | * damaged end code). Treat that as a warning.␍␊ |
| 913 | */␍␊ |
| 914 | if (png_ptr->row_number >= png_ptr->num_rows ||␍␊ |
| 915 | png_ptr->pass > 6)␍␊ |
| 916 | png_warning(png_ptr, "Truncated compressed data in IDAT");␍␊ |
| 917 | ␍␊ |
| 918 | else␍␊ |
| 919 | png_error(png_ptr, "Decompression error in IDAT");␍␊ |
| 920 | ␍␊ |
| 921 | /* Skip the check on unprocessed input */␍␊ |
| 922 | return;␍␊ |
| 923 | }␍␊ |
| 924 | ␍␊ |
| 925 | /* Did inflate output any data? */␍␊ |
| 926 | if (png_ptr->zstream.next_out != png_ptr->row_buf)␍␊ |
| 927 | {␍␊ |
| 928 | /* Is this unexpected data after the last row?␍␊ |
| 929 | * If it is, artificially terminate the LZ output␍␊ |
| 930 | * here.␍␊ |
| 931 | */␍␊ |
| 932 | if (png_ptr->row_number >= png_ptr->num_rows ||␍␊ |
| 933 | png_ptr->pass > 6)␍␊ |
| 934 | {␍␊ |
| 935 | /* Extra data. */␍␊ |
| 936 | png_warning(png_ptr, "Extra compressed data in IDAT");␍␊ |
| 937 | png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;␍␊ |
| 938 | ␍␊ |
| 939 | /* Do no more processing; skip the unprocessed␍␊ |
| 940 | * input check below.␍␊ |
| 941 | */␍␊ |
| 942 | return;␍␊ |
| 943 | }␍␊ |
| 944 | ␍␊ |
| 945 | /* Do we have a complete row? */␍␊ |
| 946 | if (png_ptr->zstream.avail_out == 0)␍␊ |
| 947 | png_push_process_row(png_ptr);␍␊ |
| 948 | }␍␊ |
| 949 | ␍␊ |
| 950 | /* And check for the end of the stream. */␍␊ |
| 951 | if (ret == Z_STREAM_END)␍␊ |
| 952 | png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;␍␊ |
| 953 | }␍␊ |
| 954 | ␍␊ |
| 955 | /* All the data should have been processed, if anything␍␊ |
| 956 | * is left at this point we have bytes of IDAT data␍␊ |
| 957 | * after the zlib end code.␍␊ |
| 958 | */␍␊ |
| 959 | if (png_ptr->zstream.avail_in > 0)␍␊ |
| 960 | png_warning(png_ptr, "Extra compression data in IDAT");␍␊ |
| 961 | }␍␊ |
| 962 | ␍␊ |
| 963 | void /* PRIVATE */␍␊ |
| 964 | png_push_process_row(png_structp png_ptr)␍␊ |
| 965 | {␍␊ |
| 966 | /* 1.5.6: row_info moved out of png_struct to a local here. */␍␊ |
| 967 | png_row_info row_info;␍␊ |
| 968 | ␍␊ |
| 969 | row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */␍␊ |
| 970 | row_info.color_type = png_ptr->color_type;␍␊ |
| 971 | row_info.bit_depth = png_ptr->bit_depth;␍␊ |
| 972 | row_info.channels = png_ptr->channels;␍␊ |
| 973 | row_info.pixel_depth = png_ptr->pixel_depth;␍␊ |
| 974 | row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);␍␊ |
| 975 | ␍␊ |
| 976 | if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)␍␊ |
| 977 | {␍␊ |
| 978 | if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)␍␊ |
| 979 | png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,␍␊ |
| 980 | png_ptr->prev_row + 1, png_ptr->row_buf[0]);␍␊ |
| 981 | else␍␊ |
| 982 | png_error(png_ptr, "bad adaptive filter value");␍␊ |
| 983 | }␍␊ |
| 984 | ␍␊ |
| 985 | /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before␍␊ |
| 986 | * 1.5.6, while the buffer really is this big in current versions of libpng␍␊ |
| 987 | * it may not be in the future, so this was changed just to copy the␍␊ |
| 988 | * interlaced row count:␍␊ |
| 989 | */␍␊ |
| 990 | png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);␍␊ |
| 991 | ␍␊ |
| 992 | #ifdef PNG_READ_TRANSFORMS_SUPPORTED␍␊ |
| 993 | if (png_ptr->transformations)␍␊ |
| 994 | png_do_read_transformations(png_ptr, &row_info);␍␊ |
| 995 | #endif␍␊ |
| 996 | ␍␊ |
| 997 | /* The transformed pixel depth should match the depth now in row_info. */␍␊ |
| 998 | if (png_ptr->transformed_pixel_depth == 0)␍␊ |
| 999 | {␍␊ |
| 1000 | png_ptr->transformed_pixel_depth = row_info.pixel_depth;␍␊ |
| 1001 | if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)␍␊ |
| 1002 | png_error(png_ptr, "progressive row overflow");␍␊ |
| 1003 | }␍␊ |
| 1004 | ␍␊ |
| 1005 | else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)␍␊ |
| 1006 | png_error(png_ptr, "internal progressive row size calculation error");␍␊ |
| 1007 | ␍␊ |
| 1008 | ␍␊ |
| 1009 | #ifdef PNG_READ_INTERLACING_SUPPORTED␍␊ |
| 1010 | /* Blow up interlaced rows to full size */␍␊ |
| 1011 | if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))␍␊ |
| 1012 | {␍␊ |
| 1013 | if (png_ptr->pass < 6)␍␊ |
| 1014 | png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,␍␊ |
| 1015 | png_ptr->transformations);␍␊ |
| 1016 | ␍␊ |
| 1017 | switch (png_ptr->pass)␍␊ |
| 1018 | {␍␊ |
| 1019 | case 0:␍␊ |
| 1020 | {␍␊ |
| 1021 | int i;␍␊ |
| 1022 | for (i = 0; i < 8 && png_ptr->pass == 0; i++)␍␊ |
| 1023 | {␍␊ |
| 1024 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1025 | png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */␍␊ |
| 1026 | }␍␊ |
| 1027 | ␍␊ |
| 1028 | if (png_ptr->pass == 2) /* Pass 1 might be empty */␍␊ |
| 1029 | {␍␊ |
| 1030 | for (i = 0; i < 4 && png_ptr->pass == 2; i++)␍␊ |
| 1031 | {␍␊ |
| 1032 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1033 | png_read_push_finish_row(png_ptr);␍␊ |
| 1034 | }␍␊ |
| 1035 | }␍␊ |
| 1036 | ␍␊ |
| 1037 | if (png_ptr->pass == 4 && png_ptr->height <= 4)␍␊ |
| 1038 | {␍␊ |
| 1039 | for (i = 0; i < 2 && png_ptr->pass == 4; i++)␍␊ |
| 1040 | {␍␊ |
| 1041 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1042 | png_read_push_finish_row(png_ptr);␍␊ |
| 1043 | }␍␊ |
| 1044 | }␍␊ |
| 1045 | ␍␊ |
| 1046 | if (png_ptr->pass == 6 && png_ptr->height <= 4)␍␊ |
| 1047 | {␍␊ |
| 1048 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1049 | png_read_push_finish_row(png_ptr);␍␊ |
| 1050 | }␍␊ |
| 1051 | ␍␊ |
| 1052 | break;␍␊ |
| 1053 | }␍␊ |
| 1054 | ␍␊ |
| 1055 | case 1:␍␊ |
| 1056 | {␍␊ |
| 1057 | int i;␍␊ |
| 1058 | for (i = 0; i < 8 && png_ptr->pass == 1; i++)␍␊ |
| 1059 | {␍␊ |
| 1060 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1061 | png_read_push_finish_row(png_ptr);␍␊ |
| 1062 | }␍␊ |
| 1063 | ␍␊ |
| 1064 | if (png_ptr->pass == 2) /* Skip top 4 generated rows */␍␊ |
| 1065 | {␍␊ |
| 1066 | for (i = 0; i < 4 && png_ptr->pass == 2; i++)␍␊ |
| 1067 | {␍␊ |
| 1068 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1069 | png_read_push_finish_row(png_ptr);␍␊ |
| 1070 | }␍␊ |
| 1071 | }␍␊ |
| 1072 | ␍␊ |
| 1073 | break;␍␊ |
| 1074 | }␍␊ |
| 1075 | ␍␊ |
| 1076 | case 2:␍␊ |
| 1077 | {␍␊ |
| 1078 | int i;␍␊ |
| 1079 | ␍␊ |
| 1080 | for (i = 0; i < 4 && png_ptr->pass == 2; i++)␍␊ |
| 1081 | {␍␊ |
| 1082 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1083 | png_read_push_finish_row(png_ptr);␍␊ |
| 1084 | }␍␊ |
| 1085 | ␍␊ |
| 1086 | for (i = 0; i < 4 && png_ptr->pass == 2; i++)␍␊ |
| 1087 | {␍␊ |
| 1088 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1089 | png_read_push_finish_row(png_ptr);␍␊ |
| 1090 | }␍␊ |
| 1091 | ␍␊ |
| 1092 | if (png_ptr->pass == 4) /* Pass 3 might be empty */␍␊ |
| 1093 | {␍␊ |
| 1094 | for (i = 0; i < 2 && png_ptr->pass == 4; i++)␍␊ |
| 1095 | {␍␊ |
| 1096 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1097 | png_read_push_finish_row(png_ptr);␍␊ |
| 1098 | }␍␊ |
| 1099 | }␍␊ |
| 1100 | ␍␊ |
| 1101 | break;␍␊ |
| 1102 | }␍␊ |
| 1103 | ␍␊ |
| 1104 | case 3:␍␊ |
| 1105 | {␍␊ |
| 1106 | int i;␍␊ |
| 1107 | ␍␊ |
| 1108 | for (i = 0; i < 4 && png_ptr->pass == 3; i++)␍␊ |
| 1109 | {␍␊ |
| 1110 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1111 | png_read_push_finish_row(png_ptr);␍␊ |
| 1112 | }␍␊ |
| 1113 | ␍␊ |
| 1114 | if (png_ptr->pass == 4) /* Skip top two generated rows */␍␊ |
| 1115 | {␍␊ |
| 1116 | for (i = 0; i < 2 && png_ptr->pass == 4; i++)␍␊ |
| 1117 | {␍␊ |
| 1118 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1119 | png_read_push_finish_row(png_ptr);␍␊ |
| 1120 | }␍␊ |
| 1121 | }␍␊ |
| 1122 | ␍␊ |
| 1123 | break;␍␊ |
| 1124 | }␍␊ |
| 1125 | ␍␊ |
| 1126 | case 4:␍␊ |
| 1127 | {␍␊ |
| 1128 | int i;␍␊ |
| 1129 | ␍␊ |
| 1130 | for (i = 0; i < 2 && png_ptr->pass == 4; i++)␍␊ |
| 1131 | {␍␊ |
| 1132 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1133 | png_read_push_finish_row(png_ptr);␍␊ |
| 1134 | }␍␊ |
| 1135 | ␍␊ |
| 1136 | for (i = 0; i < 2 && png_ptr->pass == 4; i++)␍␊ |
| 1137 | {␍␊ |
| 1138 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1139 | png_read_push_finish_row(png_ptr);␍␊ |
| 1140 | }␍␊ |
| 1141 | ␍␊ |
| 1142 | if (png_ptr->pass == 6) /* Pass 5 might be empty */␍␊ |
| 1143 | {␍␊ |
| 1144 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1145 | png_read_push_finish_row(png_ptr);␍␊ |
| 1146 | }␍␊ |
| 1147 | ␍␊ |
| 1148 | break;␍␊ |
| 1149 | }␍␊ |
| 1150 | ␍␊ |
| 1151 | case 5:␍␊ |
| 1152 | {␍␊ |
| 1153 | int i;␍␊ |
| 1154 | ␍␊ |
| 1155 | for (i = 0; i < 2 && png_ptr->pass == 5; i++)␍␊ |
| 1156 | {␍␊ |
| 1157 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1158 | png_read_push_finish_row(png_ptr);␍␊ |
| 1159 | }␍␊ |
| 1160 | ␍␊ |
| 1161 | if (png_ptr->pass == 6) /* Skip top generated row */␍␊ |
| 1162 | {␍␊ |
| 1163 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1164 | png_read_push_finish_row(png_ptr);␍␊ |
| 1165 | }␍␊ |
| 1166 | ␍␊ |
| 1167 | break;␍␊ |
| 1168 | }␍␊ |
| 1169 | ␍␊ |
| 1170 | default:␍␊ |
| 1171 | case 6:␍␊ |
| 1172 | {␍␊ |
| 1173 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1174 | png_read_push_finish_row(png_ptr);␍␊ |
| 1175 | ␍␊ |
| 1176 | if (png_ptr->pass != 6)␍␊ |
| 1177 | break;␍␊ |
| 1178 | ␍␊ |
| 1179 | png_push_have_row(png_ptr, NULL);␍␊ |
| 1180 | png_read_push_finish_row(png_ptr);␍␊ |
| 1181 | }␍␊ |
| 1182 | }␍␊ |
| 1183 | }␍␊ |
| 1184 | else␍␊ |
| 1185 | #endif␍␊ |
| 1186 | {␍␊ |
| 1187 | png_push_have_row(png_ptr, png_ptr->row_buf + 1);␍␊ |
| 1188 | png_read_push_finish_row(png_ptr);␍␊ |
| 1189 | }␍␊ |
| 1190 | }␍␊ |
| 1191 | ␍␊ |
| 1192 | void /* PRIVATE */␍␊ |
| 1193 | png_read_push_finish_row(png_structp png_ptr)␍␊ |
| 1194 | {␍␊ |
| 1195 | #ifdef PNG_READ_INTERLACING_SUPPORTED␍␊ |
| 1196 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */␍␊ |
| 1197 | ␍␊ |
| 1198 | /* Start of interlace block */␍␊ |
| 1199 | static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};␍␊ |
| 1200 | ␍␊ |
| 1201 | /* Offset to next interlace block */␍␊ |
| 1202 | static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};␍␊ |
| 1203 | ␍␊ |
| 1204 | /* Start of interlace block in the y direction */␍␊ |
| 1205 | static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};␍␊ |
| 1206 | ␍␊ |
| 1207 | /* Offset to next interlace block in the y direction */␍␊ |
| 1208 | static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};␍␊ |
| 1209 | ␍␊ |
| 1210 | /* Height of interlace block. This is not currently used - if you need␍␊ |
| 1211 | * it, uncomment it here and in png.h␍␊ |
| 1212 | static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};␍␊ |
| 1213 | */␍␊ |
| 1214 | #endif␍␊ |
| 1215 | ␍␊ |
| 1216 | png_ptr->row_number++;␍␊ |
| 1217 | if (png_ptr->row_number < png_ptr->num_rows)␍␊ |
| 1218 | return;␍␊ |
| 1219 | ␍␊ |
| 1220 | #ifdef PNG_READ_INTERLACING_SUPPORTED␍␊ |
| 1221 | if (png_ptr->interlaced)␍␊ |
| 1222 | {␍␊ |
| 1223 | png_ptr->row_number = 0;␍␊ |
| 1224 | png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);␍␊ |
| 1225 | ␍␊ |
| 1226 | do␍␊ |
| 1227 | {␍␊ |
| 1228 | png_ptr->pass++;␍␊ |
| 1229 | if ((png_ptr->pass == 1 && png_ptr->width < 5) ||␍␊ |
| 1230 | (png_ptr->pass == 3 && png_ptr->width < 3) ||␍␊ |
| 1231 | (png_ptr->pass == 5 && png_ptr->width < 2))␍␊ |
| 1232 | png_ptr->pass++;␍␊ |
| 1233 | ␍␊ |
| 1234 | if (png_ptr->pass > 7)␍␊ |
| 1235 | png_ptr->pass--;␍␊ |
| 1236 | ␍␊ |
| 1237 | if (png_ptr->pass >= 7)␍␊ |
| 1238 | break;␍␊ |
| 1239 | ␍␊ |
| 1240 | png_ptr->iwidth = (png_ptr->width +␍␊ |
| 1241 | png_pass_inc[png_ptr->pass] - 1 -␍␊ |
| 1242 | png_pass_start[png_ptr->pass]) /␍␊ |
| 1243 | png_pass_inc[png_ptr->pass];␍␊ |
| 1244 | ␍␊ |
| 1245 | if (png_ptr->transformations & PNG_INTERLACE)␍␊ |
| 1246 | break;␍␊ |
| 1247 | ␍␊ |
| 1248 | png_ptr->num_rows = (png_ptr->height +␍␊ |
| 1249 | png_pass_yinc[png_ptr->pass] - 1 -␍␊ |
| 1250 | png_pass_ystart[png_ptr->pass]) /␍␊ |
| 1251 | png_pass_yinc[png_ptr->pass];␍␊ |
| 1252 | ␍␊ |
| 1253 | } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);␍␊ |
| 1254 | }␍␊ |
| 1255 | #endif /* PNG_READ_INTERLACING_SUPPORTED */␍␊ |
| 1256 | }␍␊ |
| 1257 | ␍␊ |
| 1258 | void /* PRIVATE */␍␊ |
| 1259 | png_push_have_info(png_structp png_ptr, png_infop info_ptr)␍␊ |
| 1260 | {␍␊ |
| 1261 | if (png_ptr->info_fn != NULL)␍␊ |
| 1262 | (*(png_ptr->info_fn))(png_ptr, info_ptr);␍␊ |
| 1263 | }␍␊ |
| 1264 | ␍␊ |
| 1265 | void /* PRIVATE */␍␊ |
| 1266 | png_push_have_end(png_structp png_ptr, png_infop info_ptr)␍␊ |
| 1267 | {␍␊ |
| 1268 | if (png_ptr->end_fn != NULL)␍␊ |
| 1269 | (*(png_ptr->end_fn))(png_ptr, info_ptr);␍␊ |
| 1270 | }␍␊ |
| 1271 | ␍␊ |
| 1272 | void /* PRIVATE */␍␊ |
| 1273 | png_push_have_row(png_structp png_ptr, png_bytep row)␍␊ |
| 1274 | {␍␊ |
| 1275 | if (png_ptr->row_fn != NULL)␍␊ |
| 1276 | (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,␍␊ |
| 1277 | (int)png_ptr->pass);␍␊ |
| 1278 | }␍␊ |
| 1279 | ␍␊ |
| 1280 | #ifdef PNG_READ_INTERLACING_SUPPORTED␍␊ |
| 1281 | void PNGAPI␍␊ |
| 1282 | png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,␍␊ |
| 1283 | png_const_bytep new_row)␍␊ |
| 1284 | {␍␊ |
| 1285 | if (png_ptr == NULL)␍␊ |
| 1286 | return;␍␊ |
| 1287 | ␍␊ |
| 1288 | /* new_row is a flag here - if it is NULL then the app callback was called␍␊ |
| 1289 | * from an empty row (see the calls to png_struct::row_fn below), otherwise␍␊ |
| 1290 | * it must be png_ptr->row_buf+1␍␊ |
| 1291 | */␍␊ |
| 1292 | if (new_row != NULL)␍␊ |
| 1293 | png_combine_row(png_ptr, old_row, 1/*display*/);␍␊ |
| 1294 | }␍␊ |
| 1295 | #endif /* PNG_READ_INTERLACING_SUPPORTED */␍␊ |
| 1296 | ␍␊ |
| 1297 | void PNGAPI␍␊ |
| 1298 | png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,␍␊ |
| 1299 | png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,␍␊ |
| 1300 | png_progressive_end_ptr end_fn)␍␊ |
| 1301 | {␍␊ |
| 1302 | if (png_ptr == NULL)␍␊ |
| 1303 | return;␍␊ |
| 1304 | ␍␊ |
| 1305 | png_ptr->info_fn = info_fn;␍␊ |
| 1306 | png_ptr->row_fn = row_fn;␍␊ |
| 1307 | png_ptr->end_fn = end_fn;␍␊ |
| 1308 | ␍␊ |
| 1309 | png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);␍␊ |
| 1310 | }␍␊ |
| 1311 | ␍␊ |
| 1312 | png_voidp PNGAPI␍␊ |
| 1313 | png_get_progressive_ptr(png_const_structp png_ptr)␍␊ |
| 1314 | {␍␊ |
| 1315 | if (png_ptr == NULL)␍␊ |
| 1316 | return (NULL);␍␊ |
| 1317 | ␍␊ |
| 1318 | return png_ptr->io_ptr;␍␊ |
| 1319 | }␍␊ |
| 1320 | #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */␍␊ |
| 1321 | |
