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comparison ext/libpng-1.2.29/pngpread.c @ 0:4a0efb7baf70

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* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
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-1:000000000000 0:4a0efb7baf70
1
2 /* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.2.27 [April 29, 2008]
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 */
10
11 #define PNG_INTERNAL
12 #include "png.h"
13
14 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
15
16 /* push model modes */
17 #define PNG_READ_SIG_MODE 0
18 #define PNG_READ_CHUNK_MODE 1
19 #define PNG_READ_IDAT_MODE 2
20 #define PNG_SKIP_MODE 3
21 #define PNG_READ_tEXt_MODE 4
22 #define PNG_READ_zTXt_MODE 5
23 #define PNG_READ_DONE_MODE 6
24 #define PNG_READ_iTXt_MODE 7
25 #define PNG_ERROR_MODE 8
26
27 void PNGAPI
28 png_process_data(png_structp png_ptr, png_infop info_ptr,
29 png_bytep buffer, png_size_t buffer_size)
30 {
31 if(png_ptr == NULL || info_ptr == NULL) return;
32 png_push_restore_buffer(png_ptr, buffer, buffer_size);
33
34 while (png_ptr->buffer_size)
35 {
36 png_process_some_data(png_ptr, info_ptr);
37 }
38 }
39
40 /* What we do with the incoming data depends on what we were previously
41 * doing before we ran out of data...
42 */
43 void /* PRIVATE */
44 png_process_some_data(png_structp png_ptr, png_infop info_ptr)
45 {
46 if(png_ptr == NULL) return;
47 switch (png_ptr->process_mode)
48 {
49 case PNG_READ_SIG_MODE:
50 {
51 png_push_read_sig(png_ptr, info_ptr);
52 break;
53 }
54 case PNG_READ_CHUNK_MODE:
55 {
56 png_push_read_chunk(png_ptr, info_ptr);
57 break;
58 }
59 case PNG_READ_IDAT_MODE:
60 {
61 png_push_read_IDAT(png_ptr);
62 break;
63 }
64 #if defined(PNG_READ_tEXt_SUPPORTED)
65 case PNG_READ_tEXt_MODE:
66 {
67 png_push_read_tEXt(png_ptr, info_ptr);
68 break;
69 }
70 #endif
71 #if defined(PNG_READ_zTXt_SUPPORTED)
72 case PNG_READ_zTXt_MODE:
73 {
74 png_push_read_zTXt(png_ptr, info_ptr);
75 break;
76 }
77 #endif
78 #if defined(PNG_READ_iTXt_SUPPORTED)
79 case PNG_READ_iTXt_MODE:
80 {
81 png_push_read_iTXt(png_ptr, info_ptr);
82 break;
83 }
84 #endif
85 case PNG_SKIP_MODE:
86 {
87 png_push_crc_finish(png_ptr);
88 break;
89 }
90 default:
91 {
92 png_ptr->buffer_size = 0;
93 break;
94 }
95 }
96 }
97
98 /* Read any remaining signature bytes from the stream and compare them with
99 * the correct PNG signature. It is possible that this routine is called
100 * with bytes already read from the signature, either because they have been
101 * checked by the calling application, or because of multiple calls to this
102 * routine.
103 */
104 void /* PRIVATE */
105 png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
106 {
107 png_size_t num_checked = png_ptr->sig_bytes,
108 num_to_check = 8 - num_checked;
109
110 if (png_ptr->buffer_size < num_to_check)
111 {
112 num_to_check = png_ptr->buffer_size;
113 }
114
115 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
116 num_to_check);
117 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
118
119 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
120 {
121 if (num_checked < 4 &&
122 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
123 png_error(png_ptr, "Not a PNG file");
124 else
125 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
126 }
127 else
128 {
129 if (png_ptr->sig_bytes >= 8)
130 {
131 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
132 }
133 }
134 }
135
136 void /* PRIVATE */
137 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
138 {
139 #ifdef PNG_USE_LOCAL_ARRAYS
140 PNG_CONST PNG_IHDR;
141 PNG_CONST PNG_IDAT;
142 PNG_CONST PNG_IEND;
143 PNG_CONST PNG_PLTE;
144 #if defined(PNG_READ_bKGD_SUPPORTED)
145 PNG_CONST PNG_bKGD;
146 #endif
147 #if defined(PNG_READ_cHRM_SUPPORTED)
148 PNG_CONST PNG_cHRM;
149 #endif
150 #if defined(PNG_READ_gAMA_SUPPORTED)
151 PNG_CONST PNG_gAMA;
152 #endif
153 #if defined(PNG_READ_hIST_SUPPORTED)
154 PNG_CONST PNG_hIST;
155 #endif
156 #if defined(PNG_READ_iCCP_SUPPORTED)
157 PNG_CONST PNG_iCCP;
158 #endif
159 #if defined(PNG_READ_iTXt_SUPPORTED)
160 PNG_CONST PNG_iTXt;
161 #endif
162 #if defined(PNG_READ_oFFs_SUPPORTED)
163 PNG_CONST PNG_oFFs;
164 #endif
165 #if defined(PNG_READ_pCAL_SUPPORTED)
166 PNG_CONST PNG_pCAL;
167 #endif
168 #if defined(PNG_READ_pHYs_SUPPORTED)
169 PNG_CONST PNG_pHYs;
170 #endif
171 #if defined(PNG_READ_sBIT_SUPPORTED)
172 PNG_CONST PNG_sBIT;
173 #endif
174 #if defined(PNG_READ_sCAL_SUPPORTED)
175 PNG_CONST PNG_sCAL;
176 #endif
177 #if defined(PNG_READ_sRGB_SUPPORTED)
178 PNG_CONST PNG_sRGB;
179 #endif
180 #if defined(PNG_READ_sPLT_SUPPORTED)
181 PNG_CONST PNG_sPLT;
182 #endif
183 #if defined(PNG_READ_tEXt_SUPPORTED)
184 PNG_CONST PNG_tEXt;
185 #endif
186 #if defined(PNG_READ_tIME_SUPPORTED)
187 PNG_CONST PNG_tIME;
188 #endif
189 #if defined(PNG_READ_tRNS_SUPPORTED)
190 PNG_CONST PNG_tRNS;
191 #endif
192 #if defined(PNG_READ_zTXt_SUPPORTED)
193 PNG_CONST PNG_zTXt;
194 #endif
195 #endif /* PNG_USE_LOCAL_ARRAYS */
196 /* First we make sure we have enough data for the 4 byte chunk name
197 * and the 4 byte chunk length before proceeding with decoding the
198 * chunk data. To fully decode each of these chunks, we also make
199 * sure we have enough data in the buffer for the 4 byte CRC at the
200 * end of every chunk (except IDAT, which is handled separately).
201 */
202 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
203 {
204 png_byte chunk_length[4];
205
206 if (png_ptr->buffer_size < 8)
207 {
208 png_push_save_buffer(png_ptr);
209 return;
210 }
211
212 png_push_fill_buffer(png_ptr, chunk_length, 4);
213 png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
214 png_reset_crc(png_ptr);
215 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
216 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
217 }
218
219 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
220 if(png_ptr->mode & PNG_AFTER_IDAT)
221 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
222
223 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
224 {
225 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
226 {
227 if (png_ptr->push_length != 13)
228 png_error(png_ptr, "Invalid IHDR length");
229 png_push_save_buffer(png_ptr);
230 return;
231 }
232 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
233 }
234 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
235 {
236 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
237 {
238 png_push_save_buffer(png_ptr);
239 return;
240 }
241 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
242
243 png_ptr->process_mode = PNG_READ_DONE_MODE;
244 png_push_have_end(png_ptr, info_ptr);
245 }
246 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
247 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
248 {
249 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
250 {
251 png_push_save_buffer(png_ptr);
252 return;
253 }
254 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
255 png_ptr->mode |= PNG_HAVE_IDAT;
256 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
257 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
258 png_ptr->mode |= PNG_HAVE_PLTE;
259 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
260 {
261 if (!(png_ptr->mode & PNG_HAVE_IHDR))
262 png_error(png_ptr, "Missing IHDR before IDAT");
263 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
264 !(png_ptr->mode & PNG_HAVE_PLTE))
265 png_error(png_ptr, "Missing PLTE before IDAT");
266 }
267 }
268 #endif
269 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
270 {
271 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
272 {
273 png_push_save_buffer(png_ptr);
274 return;
275 }
276 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
277 }
278 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
279 {
280 /* If we reach an IDAT chunk, this means we have read all of the
281 * header chunks, and we can start reading the image (or if this
282 * is called after the image has been read - we have an error).
283 */
284 if (!(png_ptr->mode & PNG_HAVE_IHDR))
285 png_error(png_ptr, "Missing IHDR before IDAT");
286 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
287 !(png_ptr->mode & PNG_HAVE_PLTE))
288 png_error(png_ptr, "Missing PLTE before IDAT");
289
290 if (png_ptr->mode & PNG_HAVE_IDAT)
291 {
292 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
293 if (png_ptr->push_length == 0)
294 return;
295
296 if (png_ptr->mode & PNG_AFTER_IDAT)
297 png_error(png_ptr, "Too many IDAT's found");
298 }
299
300 png_ptr->idat_size = png_ptr->push_length;
301 png_ptr->mode |= PNG_HAVE_IDAT;
302 png_ptr->process_mode = PNG_READ_IDAT_MODE;
303 png_push_have_info(png_ptr, info_ptr);
304 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
305 png_ptr->zstream.next_out = png_ptr->row_buf;
306 return;
307 }
308 #if defined(PNG_READ_gAMA_SUPPORTED)
309 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
310 {
311 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
312 {
313 png_push_save_buffer(png_ptr);
314 return;
315 }
316 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
317 }
318 #endif
319 #if defined(PNG_READ_sBIT_SUPPORTED)
320 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
321 {
322 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
323 {
324 png_push_save_buffer(png_ptr);
325 return;
326 }
327 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
328 }
329 #endif
330 #if defined(PNG_READ_cHRM_SUPPORTED)
331 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
332 {
333 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
334 {
335 png_push_save_buffer(png_ptr);
336 return;
337 }
338 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
339 }
340 #endif
341 #if defined(PNG_READ_sRGB_SUPPORTED)
342 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
343 {
344 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
345 {
346 png_push_save_buffer(png_ptr);
347 return;
348 }
349 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
350 }
351 #endif
352 #if defined(PNG_READ_iCCP_SUPPORTED)
353 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
354 {
355 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
356 {
357 png_push_save_buffer(png_ptr);
358 return;
359 }
360 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
361 }
362 #endif
363 #if defined(PNG_READ_sPLT_SUPPORTED)
364 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
365 {
366 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
367 {
368 png_push_save_buffer(png_ptr);
369 return;
370 }
371 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
372 }
373 #endif
374 #if defined(PNG_READ_tRNS_SUPPORTED)
375 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
376 {
377 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
378 {
379 png_push_save_buffer(png_ptr);
380 return;
381 }
382 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
383 }
384 #endif
385 #if defined(PNG_READ_bKGD_SUPPORTED)
386 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
387 {
388 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
389 {
390 png_push_save_buffer(png_ptr);
391 return;
392 }
393 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
394 }
395 #endif
396 #if defined(PNG_READ_hIST_SUPPORTED)
397 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
398 {
399 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
400 {
401 png_push_save_buffer(png_ptr);
402 return;
403 }
404 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
405 }
406 #endif
407 #if defined(PNG_READ_pHYs_SUPPORTED)
408 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
409 {
410 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
411 {
412 png_push_save_buffer(png_ptr);
413 return;
414 }
415 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
416 }
417 #endif
418 #if defined(PNG_READ_oFFs_SUPPORTED)
419 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
420 {
421 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
422 {
423 png_push_save_buffer(png_ptr);
424 return;
425 }
426 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
427 }
428 #endif
429 #if defined(PNG_READ_pCAL_SUPPORTED)
430 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
431 {
432 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
433 {
434 png_push_save_buffer(png_ptr);
435 return;
436 }
437 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
438 }
439 #endif
440 #if defined(PNG_READ_sCAL_SUPPORTED)
441 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
442 {
443 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
444 {
445 png_push_save_buffer(png_ptr);
446 return;
447 }
448 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
449 }
450 #endif
451 #if defined(PNG_READ_tIME_SUPPORTED)
452 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
453 {
454 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
455 {
456 png_push_save_buffer(png_ptr);
457 return;
458 }
459 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
460 }
461 #endif
462 #if defined(PNG_READ_tEXt_SUPPORTED)
463 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
464 {
465 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
466 {
467 png_push_save_buffer(png_ptr);
468 return;
469 }
470 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
471 }
472 #endif
473 #if defined(PNG_READ_zTXt_SUPPORTED)
474 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
475 {
476 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
477 {
478 png_push_save_buffer(png_ptr);
479 return;
480 }
481 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
482 }
483 #endif
484 #if defined(PNG_READ_iTXt_SUPPORTED)
485 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
486 {
487 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
488 {
489 png_push_save_buffer(png_ptr);
490 return;
491 }
492 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
493 }
494 #endif
495 else
496 {
497 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
498 {
499 png_push_save_buffer(png_ptr);
500 return;
501 }
502 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
503 }
504
505 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
506 }
507
508 void /* PRIVATE */
509 png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
510 {
511 png_ptr->process_mode = PNG_SKIP_MODE;
512 png_ptr->skip_length = skip;
513 }
514
515 void /* PRIVATE */
516 png_push_crc_finish(png_structp png_ptr)
517 {
518 if (png_ptr->skip_length && png_ptr->save_buffer_size)
519 {
520 png_size_t save_size;
521
522 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
523 save_size = (png_size_t)png_ptr->skip_length;
524 else
525 save_size = png_ptr->save_buffer_size;
526
527 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
528
529 png_ptr->skip_length -= save_size;
530 png_ptr->buffer_size -= save_size;
531 png_ptr->save_buffer_size -= save_size;
532 png_ptr->save_buffer_ptr += save_size;
533 }
534 if (png_ptr->skip_length && png_ptr->current_buffer_size)
535 {
536 png_size_t save_size;
537
538 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
539 save_size = (png_size_t)png_ptr->skip_length;
540 else
541 save_size = png_ptr->current_buffer_size;
542
543 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
544
545 png_ptr->skip_length -= save_size;
546 png_ptr->buffer_size -= save_size;
547 png_ptr->current_buffer_size -= save_size;
548 png_ptr->current_buffer_ptr += save_size;
549 }
550 if (!png_ptr->skip_length)
551 {
552 if (png_ptr->buffer_size < 4)
553 {
554 png_push_save_buffer(png_ptr);
555 return;
556 }
557
558 png_crc_finish(png_ptr, 0);
559 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
560 }
561 }
562
563 void PNGAPI
564 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
565 {
566 png_bytep ptr;
567
568 if(png_ptr == NULL) return;
569 ptr = buffer;
570 if (png_ptr->save_buffer_size)
571 {
572 png_size_t save_size;
573
574 if (length < png_ptr->save_buffer_size)
575 save_size = length;
576 else
577 save_size = png_ptr->save_buffer_size;
578
579 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
580 length -= save_size;
581 ptr += save_size;
582 png_ptr->buffer_size -= save_size;
583 png_ptr->save_buffer_size -= save_size;
584 png_ptr->save_buffer_ptr += save_size;
585 }
586 if (length && png_ptr->current_buffer_size)
587 {
588 png_size_t save_size;
589
590 if (length < png_ptr->current_buffer_size)
591 save_size = length;
592 else
593 save_size = png_ptr->current_buffer_size;
594
595 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
596 png_ptr->buffer_size -= save_size;
597 png_ptr->current_buffer_size -= save_size;
598 png_ptr->current_buffer_ptr += save_size;
599 }
600 }
601
602 void /* PRIVATE */
603 png_push_save_buffer(png_structp png_ptr)
604 {
605 if (png_ptr->save_buffer_size)
606 {
607 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
608 {
609 png_size_t i,istop;
610 png_bytep sp;
611 png_bytep dp;
612
613 istop = png_ptr->save_buffer_size;
614 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
615 i < istop; i++, sp++, dp++)
616 {
617 *dp = *sp;
618 }
619 }
620 }
621 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
622 png_ptr->save_buffer_max)
623 {
624 png_size_t new_max;
625 png_bytep old_buffer;
626
627 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
628 (png_ptr->current_buffer_size + 256))
629 {
630 png_error(png_ptr, "Potential overflow of save_buffer");
631 }
632 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
633 old_buffer = png_ptr->save_buffer;
634 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
635 (png_uint_32)new_max);
636 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
637 png_free(png_ptr, old_buffer);
638 png_ptr->save_buffer_max = new_max;
639 }
640 if (png_ptr->current_buffer_size)
641 {
642 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
643 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
644 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
645 png_ptr->current_buffer_size = 0;
646 }
647 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
648 png_ptr->buffer_size = 0;
649 }
650
651 void /* PRIVATE */
652 png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
653 png_size_t buffer_length)
654 {
655 png_ptr->current_buffer = buffer;
656 png_ptr->current_buffer_size = buffer_length;
657 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
658 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
659 }
660
661 void /* PRIVATE */
662 png_push_read_IDAT(png_structp png_ptr)
663 {
664 #ifdef PNG_USE_LOCAL_ARRAYS
665 PNG_CONST PNG_IDAT;
666 #endif
667 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
668 {
669 png_byte chunk_length[4];
670
671 if (png_ptr->buffer_size < 8)
672 {
673 png_push_save_buffer(png_ptr);
674 return;
675 }
676
677 png_push_fill_buffer(png_ptr, chunk_length, 4);
678 png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
679 png_reset_crc(png_ptr);
680 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
681 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
682
683 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
684 {
685 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
686 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
687 png_error(png_ptr, "Not enough compressed data");
688 return;
689 }
690
691 png_ptr->idat_size = png_ptr->push_length;
692 }
693 if (png_ptr->idat_size && png_ptr->save_buffer_size)
694 {
695 png_size_t save_size;
696
697 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
698 {
699 save_size = (png_size_t)png_ptr->idat_size;
700 /* check for overflow */
701 if((png_uint_32)save_size != png_ptr->idat_size)
702 png_error(png_ptr, "save_size overflowed in pngpread");
703 }
704 else
705 save_size = png_ptr->save_buffer_size;
706
707 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
708 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
709 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
710 png_ptr->idat_size -= save_size;
711 png_ptr->buffer_size -= save_size;
712 png_ptr->save_buffer_size -= save_size;
713 png_ptr->save_buffer_ptr += save_size;
714 }
715 if (png_ptr->idat_size && png_ptr->current_buffer_size)
716 {
717 png_size_t save_size;
718
719 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
720 {
721 save_size = (png_size_t)png_ptr->idat_size;
722 /* check for overflow */
723 if((png_uint_32)save_size != png_ptr->idat_size)
724 png_error(png_ptr, "save_size overflowed in pngpread");
725 }
726 else
727 save_size = png_ptr->current_buffer_size;
728
729 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
730 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
731 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
732
733 png_ptr->idat_size -= save_size;
734 png_ptr->buffer_size -= save_size;
735 png_ptr->current_buffer_size -= save_size;
736 png_ptr->current_buffer_ptr += save_size;
737 }
738 if (!png_ptr->idat_size)
739 {
740 if (png_ptr->buffer_size < 4)
741 {
742 png_push_save_buffer(png_ptr);
743 return;
744 }
745
746 png_crc_finish(png_ptr, 0);
747 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
748 png_ptr->mode |= PNG_AFTER_IDAT;
749 }
750 }
751
752 void /* PRIVATE */
753 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
754 png_size_t buffer_length)
755 {
756 int ret;
757
758 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
759 png_error(png_ptr, "Extra compression data");
760
761 png_ptr->zstream.next_in = buffer;
762 png_ptr->zstream.avail_in = (uInt)buffer_length;
763 for(;;)
764 {
765 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
766 if (ret != Z_OK)
767 {
768 if (ret == Z_STREAM_END)
769 {
770 if (png_ptr->zstream.avail_in)
771 png_error(png_ptr, "Extra compressed data");
772 if (!(png_ptr->zstream.avail_out))
773 {
774 png_push_process_row(png_ptr);
775 }
776
777 png_ptr->mode |= PNG_AFTER_IDAT;
778 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
779 break;
780 }
781 else if (ret == Z_BUF_ERROR)
782 break;
783 else
784 png_error(png_ptr, "Decompression Error");
785 }
786 if (!(png_ptr->zstream.avail_out))
787 {
788 if ((
789 #if defined(PNG_READ_INTERLACING_SUPPORTED)
790 png_ptr->interlaced && png_ptr->pass > 6) ||
791 (!png_ptr->interlaced &&
792 #endif
793 png_ptr->row_number == png_ptr->num_rows))
794 {
795 if (png_ptr->zstream.avail_in)
796 png_warning(png_ptr, "Too much data in IDAT chunks");
797 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
798 break;
799 }
800 png_push_process_row(png_ptr);
801 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
802 png_ptr->zstream.next_out = png_ptr->row_buf;
803 }
804 else
805 break;
806 }
807 }
808
809 void /* PRIVATE */
810 png_push_process_row(png_structp png_ptr)
811 {
812 png_ptr->row_info.color_type = png_ptr->color_type;
813 png_ptr->row_info.width = png_ptr->iwidth;
814 png_ptr->row_info.channels = png_ptr->channels;
815 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
816 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
817
818 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
819 png_ptr->row_info.width);
820
821 png_read_filter_row(png_ptr, &(png_ptr->row_info),
822 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
823 (int)(png_ptr->row_buf[0]));
824
825 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
826 png_ptr->rowbytes + 1);
827
828 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
829 png_do_read_transformations(png_ptr);
830
831 #if defined(PNG_READ_INTERLACING_SUPPORTED)
832 /* blow up interlaced rows to full size */
833 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
834 {
835 if (png_ptr->pass < 6)
836 /* old interface (pre-1.0.9):
837 png_do_read_interlace(&(png_ptr->row_info),
838 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
839 */
840 png_do_read_interlace(png_ptr);
841
842 switch (png_ptr->pass)
843 {
844 case 0:
845 {
846 int i;
847 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
848 {
849 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
850 png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */
851 }
852 if (png_ptr->pass == 2) /* pass 1 might be empty */
853 {
854 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
855 {
856 png_push_have_row(png_ptr, png_bytep_NULL);
857 png_read_push_finish_row(png_ptr);
858 }
859 }
860 if (png_ptr->pass == 4 && png_ptr->height <= 4)
861 {
862 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
863 {
864 png_push_have_row(png_ptr, png_bytep_NULL);
865 png_read_push_finish_row(png_ptr);
866 }
867 }
868 if (png_ptr->pass == 6 && png_ptr->height <= 4)
869 {
870 png_push_have_row(png_ptr, png_bytep_NULL);
871 png_read_push_finish_row(png_ptr);
872 }
873 break;
874 }
875 case 1:
876 {
877 int i;
878 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
879 {
880 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
881 png_read_push_finish_row(png_ptr);
882 }
883 if (png_ptr->pass == 2) /* skip top 4 generated rows */
884 {
885 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
886 {
887 png_push_have_row(png_ptr, png_bytep_NULL);
888 png_read_push_finish_row(png_ptr);
889 }
890 }
891 break;
892 }
893 case 2:
894 {
895 int i;
896 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
897 {
898 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
899 png_read_push_finish_row(png_ptr);
900 }
901 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
902 {
903 png_push_have_row(png_ptr, png_bytep_NULL);
904 png_read_push_finish_row(png_ptr);
905 }
906 if (png_ptr->pass == 4) /* pass 3 might be empty */
907 {
908 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
909 {
910 png_push_have_row(png_ptr, png_bytep_NULL);
911 png_read_push_finish_row(png_ptr);
912 }
913 }
914 break;
915 }
916 case 3:
917 {
918 int i;
919 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
920 {
921 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
922 png_read_push_finish_row(png_ptr);
923 }
924 if (png_ptr->pass == 4) /* skip top two generated rows */
925 {
926 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
927 {
928 png_push_have_row(png_ptr, png_bytep_NULL);
929 png_read_push_finish_row(png_ptr);
930 }
931 }
932 break;
933 }
934 case 4:
935 {
936 int i;
937 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
938 {
939 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
940 png_read_push_finish_row(png_ptr);
941 }
942 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
943 {
944 png_push_have_row(png_ptr, png_bytep_NULL);
945 png_read_push_finish_row(png_ptr);
946 }
947 if (png_ptr->pass == 6) /* pass 5 might be empty */
948 {
949 png_push_have_row(png_ptr, png_bytep_NULL);
950 png_read_push_finish_row(png_ptr);
951 }
952 break;
953 }
954 case 5:
955 {
956 int i;
957 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
958 {
959 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
960 png_read_push_finish_row(png_ptr);
961 }
962 if (png_ptr->pass == 6) /* skip top generated row */
963 {
964 png_push_have_row(png_ptr, png_bytep_NULL);
965 png_read_push_finish_row(png_ptr);
966 }
967 break;
968 }
969 case 6:
970 {
971 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
972 png_read_push_finish_row(png_ptr);
973 if (png_ptr->pass != 6)
974 break;
975 png_push_have_row(png_ptr, png_bytep_NULL);
976 png_read_push_finish_row(png_ptr);
977 }
978 }
979 }
980 else
981 #endif
982 {
983 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
984 png_read_push_finish_row(png_ptr);
985 }
986 }
987
988 void /* PRIVATE */
989 png_read_push_finish_row(png_structp png_ptr)
990 {
991 #ifdef PNG_USE_LOCAL_ARRAYS
992 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
993
994 /* start of interlace block */
995 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
996
997 /* offset to next interlace block */
998 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
999
1000 /* start of interlace block in the y direction */
1001 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1002
1003 /* offset to next interlace block in the y direction */
1004 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1005
1006 /* Height of interlace block. This is not currently used - if you need
1007 * it, uncomment it here and in png.h
1008 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1009 */
1010 #endif
1011
1012 png_ptr->row_number++;
1013 if (png_ptr->row_number < png_ptr->num_rows)
1014 return;
1015
1016 if (png_ptr->interlaced)
1017 {
1018 png_ptr->row_number = 0;
1019 png_memset_check(png_ptr, png_ptr->prev_row, 0,
1020 png_ptr->rowbytes + 1);
1021 do
1022 {
1023 int pass;
1024 pass = png_ptr->pass;
1025 pass++;
1026 if ((pass == 1 && png_ptr->width < 5) ||
1027 (pass == 3 && png_ptr->width < 3) ||
1028 (pass == 5 && png_ptr->width < 2))
1029 pass++;
1030
1031 if (pass > 7)
1032 pass--;
1033 png_ptr->pass = (png_byte) pass;
1034 if (pass < 7)
1035 {
1036 png_ptr->iwidth = (png_ptr->width +
1037 png_pass_inc[pass] - 1 -
1038 png_pass_start[pass]) /
1039 png_pass_inc[pass];
1040
1041 png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
1042 png_ptr->iwidth) + 1;
1043
1044 if (png_ptr->transformations & PNG_INTERLACE)
1045 break;
1046
1047 png_ptr->num_rows = (png_ptr->height +
1048 png_pass_yinc[pass] - 1 -
1049 png_pass_ystart[pass]) /
1050 png_pass_yinc[pass];
1051 }
1052 else
1053 break;
1054
1055 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1056 }
1057 }
1058
1059 #if defined(PNG_READ_tEXt_SUPPORTED)
1060 void /* PRIVATE */
1061 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1062 length)
1063 {
1064 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1065 {
1066 png_error(png_ptr, "Out of place tEXt");
1067 info_ptr = info_ptr; /* to quiet some compiler warnings */
1068 }
1069
1070 #ifdef PNG_MAX_MALLOC_64K
1071 png_ptr->skip_length = 0; /* This may not be necessary */
1072
1073 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1074 {
1075 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1076 png_ptr->skip_length = length - (png_uint_32)65535L;
1077 length = (png_uint_32)65535L;
1078 }
1079 #endif
1080
1081 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1082 (png_uint_32)(length+1));
1083 png_ptr->current_text[length] = '\0';
1084 png_ptr->current_text_ptr = png_ptr->current_text;
1085 png_ptr->current_text_size = (png_size_t)length;
1086 png_ptr->current_text_left = (png_size_t)length;
1087 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1088 }
1089
1090 void /* PRIVATE */
1091 png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1092 {
1093 if (png_ptr->buffer_size && png_ptr->current_text_left)
1094 {
1095 png_size_t text_size;
1096
1097 if (png_ptr->buffer_size < png_ptr->current_text_left)
1098 text_size = png_ptr->buffer_size;
1099 else
1100 text_size = png_ptr->current_text_left;
1101 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1102 png_ptr->current_text_left -= text_size;
1103 png_ptr->current_text_ptr += text_size;
1104 }
1105 if (!(png_ptr->current_text_left))
1106 {
1107 png_textp text_ptr;
1108 png_charp text;
1109 png_charp key;
1110 int ret;
1111
1112 if (png_ptr->buffer_size < 4)
1113 {
1114 png_push_save_buffer(png_ptr);
1115 return;
1116 }
1117
1118 png_push_crc_finish(png_ptr);
1119
1120 #if defined(PNG_MAX_MALLOC_64K)
1121 if (png_ptr->skip_length)
1122 return;
1123 #endif
1124
1125 key = png_ptr->current_text;
1126
1127 for (text = key; *text; text++)
1128 /* empty loop */ ;
1129
1130 if (text < key + png_ptr->current_text_size)
1131 text++;
1132
1133 text_ptr = (png_textp)png_malloc(png_ptr,
1134 (png_uint_32)png_sizeof(png_text));
1135 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1136 text_ptr->key = key;
1137 #ifdef PNG_iTXt_SUPPORTED
1138 text_ptr->lang = NULL;
1139 text_ptr->lang_key = NULL;
1140 #endif
1141 text_ptr->text = text;
1142
1143 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1144
1145 png_free(png_ptr, key);
1146 png_free(png_ptr, text_ptr);
1147 png_ptr->current_text = NULL;
1148
1149 if (ret)
1150 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1151 }
1152 }
1153 #endif
1154
1155 #if defined(PNG_READ_zTXt_SUPPORTED)
1156 void /* PRIVATE */
1157 png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1158 length)
1159 {
1160 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1161 {
1162 png_error(png_ptr, "Out of place zTXt");
1163 info_ptr = info_ptr; /* to quiet some compiler warnings */
1164 }
1165
1166 #ifdef PNG_MAX_MALLOC_64K
1167 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1168 * to be able to store the uncompressed data. Actually, the threshold
1169 * is probably around 32K, but it isn't as definite as 64K is.
1170 */
1171 if (length > (png_uint_32)65535L)
1172 {
1173 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1174 png_push_crc_skip(png_ptr, length);
1175 return;
1176 }
1177 #endif
1178
1179 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1180 (png_uint_32)(length+1));
1181 png_ptr->current_text[length] = '\0';
1182 png_ptr->current_text_ptr = png_ptr->current_text;
1183 png_ptr->current_text_size = (png_size_t)length;
1184 png_ptr->current_text_left = (png_size_t)length;
1185 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1186 }
1187
1188 void /* PRIVATE */
1189 png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1190 {
1191 if (png_ptr->buffer_size && png_ptr->current_text_left)
1192 {
1193 png_size_t text_size;
1194
1195 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1196 text_size = png_ptr->buffer_size;
1197 else
1198 text_size = png_ptr->current_text_left;
1199 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1200 png_ptr->current_text_left -= text_size;
1201 png_ptr->current_text_ptr += text_size;
1202 }
1203 if (!(png_ptr->current_text_left))
1204 {
1205 png_textp text_ptr;
1206 png_charp text;
1207 png_charp key;
1208 int ret;
1209 png_size_t text_size, key_size;
1210
1211 if (png_ptr->buffer_size < 4)
1212 {
1213 png_push_save_buffer(png_ptr);
1214 return;
1215 }
1216
1217 png_push_crc_finish(png_ptr);
1218
1219 key = png_ptr->current_text;
1220
1221 for (text = key; *text; text++)
1222 /* empty loop */ ;
1223
1224 /* zTXt can't have zero text */
1225 if (text >= key + png_ptr->current_text_size)
1226 {
1227 png_ptr->current_text = NULL;
1228 png_free(png_ptr, key);
1229 return;
1230 }
1231
1232 text++;
1233
1234 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
1235 {
1236 png_ptr->current_text = NULL;
1237 png_free(png_ptr, key);
1238 return;
1239 }
1240
1241 text++;
1242
1243 png_ptr->zstream.next_in = (png_bytep )text;
1244 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1245 (text - key));
1246 png_ptr->zstream.next_out = png_ptr->zbuf;
1247 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1248
1249 key_size = text - key;
1250 text_size = 0;
1251 text = NULL;
1252 ret = Z_STREAM_END;
1253
1254 while (png_ptr->zstream.avail_in)
1255 {
1256 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1257 if (ret != Z_OK && ret != Z_STREAM_END)
1258 {
1259 inflateReset(&png_ptr->zstream);
1260 png_ptr->zstream.avail_in = 0;
1261 png_ptr->current_text = NULL;
1262 png_free(png_ptr, key);
1263 png_free(png_ptr, text);
1264 return;
1265 }
1266 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1267 {
1268 if (text == NULL)
1269 {
1270 text = (png_charp)png_malloc(png_ptr,
1271 (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1272 + key_size + 1));
1273 png_memcpy(text + key_size, png_ptr->zbuf,
1274 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1275 png_memcpy(text, key, key_size);
1276 text_size = key_size + png_ptr->zbuf_size -
1277 png_ptr->zstream.avail_out;
1278 *(text + text_size) = '\0';
1279 }
1280 else
1281 {
1282 png_charp tmp;
1283
1284 tmp = text;
1285 text = (png_charp)png_malloc(png_ptr, text_size +
1286 (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1287 + 1));
1288 png_memcpy(text, tmp, text_size);
1289 png_free(png_ptr, tmp);
1290 png_memcpy(text + text_size, png_ptr->zbuf,
1291 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1292 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1293 *(text + text_size) = '\0';
1294 }
1295 if (ret != Z_STREAM_END)
1296 {
1297 png_ptr->zstream.next_out = png_ptr->zbuf;
1298 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1299 }
1300 }
1301 else
1302 {
1303 break;
1304 }
1305
1306 if (ret == Z_STREAM_END)
1307 break;
1308 }
1309
1310 inflateReset(&png_ptr->zstream);
1311 png_ptr->zstream.avail_in = 0;
1312
1313 if (ret != Z_STREAM_END)
1314 {
1315 png_ptr->current_text = NULL;
1316 png_free(png_ptr, key);
1317 png_free(png_ptr, text);
1318 return;
1319 }
1320
1321 png_ptr->current_text = NULL;
1322 png_free(png_ptr, key);
1323 key = text;
1324 text += key_size;
1325
1326 text_ptr = (png_textp)png_malloc(png_ptr,
1327 (png_uint_32)png_sizeof(png_text));
1328 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1329 text_ptr->key = key;
1330 #ifdef PNG_iTXt_SUPPORTED
1331 text_ptr->lang = NULL;
1332 text_ptr->lang_key = NULL;
1333 #endif
1334 text_ptr->text = text;
1335
1336 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1337
1338 png_free(png_ptr, key);
1339 png_free(png_ptr, text_ptr);
1340
1341 if (ret)
1342 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1343 }
1344 }
1345 #endif
1346
1347 #if defined(PNG_READ_iTXt_SUPPORTED)
1348 void /* PRIVATE */
1349 png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1350 length)
1351 {
1352 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1353 {
1354 png_error(png_ptr, "Out of place iTXt");
1355 info_ptr = info_ptr; /* to quiet some compiler warnings */
1356 }
1357
1358 #ifdef PNG_MAX_MALLOC_64K
1359 png_ptr->skip_length = 0; /* This may not be necessary */
1360
1361 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1362 {
1363 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1364 png_ptr->skip_length = length - (png_uint_32)65535L;
1365 length = (png_uint_32)65535L;
1366 }
1367 #endif
1368
1369 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1370 (png_uint_32)(length+1));
1371 png_ptr->current_text[length] = '\0';
1372 png_ptr->current_text_ptr = png_ptr->current_text;
1373 png_ptr->current_text_size = (png_size_t)length;
1374 png_ptr->current_text_left = (png_size_t)length;
1375 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1376 }
1377
1378 void /* PRIVATE */
1379 png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1380 {
1381
1382 if (png_ptr->buffer_size && png_ptr->current_text_left)
1383 {
1384 png_size_t text_size;
1385
1386 if (png_ptr->buffer_size < png_ptr->current_text_left)
1387 text_size = png_ptr->buffer_size;
1388 else
1389 text_size = png_ptr->current_text_left;
1390 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1391 png_ptr->current_text_left -= text_size;
1392 png_ptr->current_text_ptr += text_size;
1393 }
1394 if (!(png_ptr->current_text_left))
1395 {
1396 png_textp text_ptr;
1397 png_charp key;
1398 int comp_flag;
1399 png_charp lang;
1400 png_charp lang_key;
1401 png_charp text;
1402 int ret;
1403
1404 if (png_ptr->buffer_size < 4)
1405 {
1406 png_push_save_buffer(png_ptr);
1407 return;
1408 }
1409
1410 png_push_crc_finish(png_ptr);
1411
1412 #if defined(PNG_MAX_MALLOC_64K)
1413 if (png_ptr->skip_length)
1414 return;
1415 #endif
1416
1417 key = png_ptr->current_text;
1418
1419 for (lang = key; *lang; lang++)
1420 /* empty loop */ ;
1421
1422 if (lang < key + png_ptr->current_text_size - 3)
1423 lang++;
1424
1425 comp_flag = *lang++;
1426 lang++; /* skip comp_type, always zero */
1427
1428 for (lang_key = lang; *lang_key; lang_key++)
1429 /* empty loop */ ;
1430 lang_key++; /* skip NUL separator */
1431
1432 text=lang_key;
1433 if (lang_key < key + png_ptr->current_text_size - 1)
1434 {
1435 for (; *text; text++)
1436 /* empty loop */ ;
1437 }
1438
1439 if (text < key + png_ptr->current_text_size)
1440 text++;
1441
1442 text_ptr = (png_textp)png_malloc(png_ptr,
1443 (png_uint_32)png_sizeof(png_text));
1444 text_ptr->compression = comp_flag + 2;
1445 text_ptr->key = key;
1446 text_ptr->lang = lang;
1447 text_ptr->lang_key = lang_key;
1448 text_ptr->text = text;
1449 text_ptr->text_length = 0;
1450 text_ptr->itxt_length = png_strlen(text);
1451
1452 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1453
1454 png_ptr->current_text = NULL;
1455
1456 png_free(png_ptr, text_ptr);
1457 if (ret)
1458 png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1459 }
1460 }
1461 #endif
1462
1463 /* This function is called when we haven't found a handler for this
1464 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1465 * name or a critical chunk), the chunk is (currently) silently ignored.
1466 */
1467 void /* PRIVATE */
1468 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1469 length)
1470 {
1471 png_uint_32 skip=0;
1472 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
1473
1474 if (!(png_ptr->chunk_name[0] & 0x20))
1475 {
1476 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1477 if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1478 PNG_HANDLE_CHUNK_ALWAYS
1479 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1480 && png_ptr->read_user_chunk_fn == NULL
1481 #endif
1482 )
1483 #endif
1484 png_chunk_error(png_ptr, "unknown critical chunk");
1485
1486 info_ptr = info_ptr; /* to quiet some compiler warnings */
1487 }
1488
1489 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1490 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1491 {
1492 #ifdef PNG_MAX_MALLOC_64K
1493 if (length > (png_uint_32)65535L)
1494 {
1495 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1496 skip = length - (png_uint_32)65535L;
1497 length = (png_uint_32)65535L;
1498 }
1499 #endif
1500 png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1501 (png_charp)png_ptr->chunk_name,
1502 png_sizeof(png_ptr->unknown_chunk.name));
1503 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]='\0';
1504
1505 png_ptr->unknown_chunk.size = (png_size_t)length;
1506 if (length == 0)
1507 png_ptr->unknown_chunk.data = NULL;
1508 else
1509 {
1510 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
1511 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1512 }
1513 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1514 if(png_ptr->read_user_chunk_fn != NULL)
1515 {
1516 /* callback to user unknown chunk handler */
1517 int ret;
1518 ret = (*(png_ptr->read_user_chunk_fn))
1519 (png_ptr, &png_ptr->unknown_chunk);
1520 if (ret < 0)
1521 png_chunk_error(png_ptr, "error in user chunk");
1522 if (ret == 0)
1523 {
1524 if (!(png_ptr->chunk_name[0] & 0x20))
1525 if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1526 PNG_HANDLE_CHUNK_ALWAYS)
1527 png_chunk_error(png_ptr, "unknown critical chunk");
1528 png_set_unknown_chunks(png_ptr, info_ptr,
1529 &png_ptr->unknown_chunk, 1);
1530 }
1531 }
1532 else
1533 #endif
1534 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1535 png_free(png_ptr, png_ptr->unknown_chunk.data);
1536 png_ptr->unknown_chunk.data = NULL;
1537 }
1538 else
1539 #endif
1540 skip=length;
1541 png_push_crc_skip(png_ptr, skip);
1542 }
1543
1544 void /* PRIVATE */
1545 png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1546 {
1547 if (png_ptr->info_fn != NULL)
1548 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1549 }
1550
1551 void /* PRIVATE */
1552 png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1553 {
1554 if (png_ptr->end_fn != NULL)
1555 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1556 }
1557
1558 void /* PRIVATE */
1559 png_push_have_row(png_structp png_ptr, png_bytep row)
1560 {
1561 if (png_ptr->row_fn != NULL)
1562 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1563 (int)png_ptr->pass);
1564 }
1565
1566 void PNGAPI
1567 png_progressive_combine_row (png_structp png_ptr,
1568 png_bytep old_row, png_bytep new_row)
1569 {
1570 #ifdef PNG_USE_LOCAL_ARRAYS
1571 PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1572 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1573 #endif
1574 if(png_ptr == NULL) return;
1575 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1576 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1577 }
1578
1579 void PNGAPI
1580 png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1581 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1582 png_progressive_end_ptr end_fn)
1583 {
1584 if(png_ptr == NULL) return;
1585 png_ptr->info_fn = info_fn;
1586 png_ptr->row_fn = row_fn;
1587 png_ptr->end_fn = end_fn;
1588
1589 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1590 }
1591
1592 png_voidp PNGAPI
1593 png_get_progressive_ptr(png_structp png_ptr)
1594 {
1595 if(png_ptr == NULL) return (NULL);
1596 return png_ptr->io_ptr;
1597 }
1598 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */