source: trunk/src/3rdparty/libpng/pngpread.c@ 681

Last change on this file since 681 was 561, checked in by Dmitry A. Kuminov, 16 years ago

trunk: Merged in qt 4.6.1 sources.
File size: 46.3 KB
Line 
1
2/* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.2.38 [July 16, 2009]
5 * Copyright (c) 1998-2009 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#define PNG_INTERNAL
15#include "png.h"
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
29void PNGAPI
30png_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/* What we do with the incoming data depends on what we were previously
45 * doing before we ran out of data...
46 */
47void /* PRIVATE */
48png_process_some_data(png_structp png_ptr, png_infop info_ptr)
49{
50 if (png_ptr == NULL)
51 return;
52
53 switch (png_ptr->process_mode)
54 {
55 case PNG_READ_SIG_MODE:
56 {
57 png_push_read_sig(png_ptr, info_ptr);
58 break;
59 }
60
61 case PNG_READ_CHUNK_MODE:
62 {
63 png_push_read_chunk(png_ptr, info_ptr);
64 break;
65 }
66
67 case PNG_READ_IDAT_MODE:
68 {
69 png_push_read_IDAT(png_ptr);
70 break;
71 }
72
73#if defined(PNG_READ_tEXt_SUPPORTED)
74 case PNG_READ_tEXt_MODE:
75 {
76 png_push_read_tEXt(png_ptr, info_ptr);
77 break;
78 }
79
80#endif
81#if defined(PNG_READ_zTXt_SUPPORTED)
82 case PNG_READ_zTXt_MODE:
83 {
84 png_push_read_zTXt(png_ptr, info_ptr);
85 break;
86 }
87
88#endif
89#if defined(PNG_READ_iTXt_SUPPORTED)
90 case PNG_READ_iTXt_MODE:
91 {
92 png_push_read_iTXt(png_ptr, info_ptr);
93 break;
94 }
95
96#endif
97 case PNG_SKIP_MODE:
98 {
99 png_push_crc_finish(png_ptr);
100 break;
101 }
102
103 default:
104 {
105 png_ptr->buffer_size = 0;
106 break;
107 }
108 }
109}
110
111/* Read any remaining signature bytes from the stream and compare them with
112 * the correct PNG signature. It is possible that this routine is called
113 * with bytes already read from the signature, either because they have been
114 * checked by the calling application, or because of multiple calls to this
115 * routine.
116 */
117void /* PRIVATE */
118png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
119{
120 png_size_t num_checked = png_ptr->sig_bytes,
121 num_to_check = 8 - num_checked;
122
123 if (png_ptr->buffer_size < num_to_check)
124 {
125 num_to_check = png_ptr->buffer_size;
126 }
127
128 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
129 num_to_check);
130 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
131
132 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
133 {
134 if (num_checked < 4 &&
135 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
136 png_error(png_ptr, "Not a PNG file");
137 else
138 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
139 }
140 else
141 {
142 if (png_ptr->sig_bytes >= 8)
143 {
144 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
145 }
146 }
147}
148
149void /* PRIVATE */
150png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
151{
152#ifdef PNG_USE_LOCAL_ARRAYS
153 PNG_CONST PNG_IHDR;
154 PNG_CONST PNG_IDAT;
155 PNG_CONST PNG_IEND;
156 PNG_CONST PNG_PLTE;
157#if defined(PNG_READ_bKGD_SUPPORTED)
158 PNG_CONST PNG_bKGD;
159#endif
160#if defined(PNG_READ_cHRM_SUPPORTED)
161 PNG_CONST PNG_cHRM;
162#endif
163#if defined(PNG_READ_gAMA_SUPPORTED)
164 PNG_CONST PNG_gAMA;
165#endif
166#if defined(PNG_READ_hIST_SUPPORTED)
167 PNG_CONST PNG_hIST;
168#endif
169#if defined(PNG_READ_iCCP_SUPPORTED)
170 PNG_CONST PNG_iCCP;
171#endif
172#if defined(PNG_READ_iTXt_SUPPORTED)
173 PNG_CONST PNG_iTXt;
174#endif
175#if defined(PNG_READ_oFFs_SUPPORTED)
176 PNG_CONST PNG_oFFs;
177#endif
178#if defined(PNG_READ_pCAL_SUPPORTED)
179 PNG_CONST PNG_pCAL;
180#endif
181#if defined(PNG_READ_pHYs_SUPPORTED)
182 PNG_CONST PNG_pHYs;
183#endif
184#if defined(PNG_READ_sBIT_SUPPORTED)
185 PNG_CONST PNG_sBIT;
186#endif
187#if defined(PNG_READ_sCAL_SUPPORTED)
188 PNG_CONST PNG_sCAL;
189#endif
190#if defined(PNG_READ_sRGB_SUPPORTED)
191 PNG_CONST PNG_sRGB;
192#endif
193#if defined(PNG_READ_sPLT_SUPPORTED)
194 PNG_CONST PNG_sPLT;
195#endif
196#if defined(PNG_READ_tEXt_SUPPORTED)
197 PNG_CONST PNG_tEXt;
198#endif
199#if defined(PNG_READ_tIME_SUPPORTED)
200 PNG_CONST PNG_tIME;
201#endif
202#if defined(PNG_READ_tRNS_SUPPORTED)
203 PNG_CONST PNG_tRNS;
204#endif
205#if defined(PNG_READ_zTXt_SUPPORTED)
206 PNG_CONST PNG_zTXt;
207#endif
208#endif /* PNG_USE_LOCAL_ARRAYS */
209 /* First we make sure we have enough data for the 4 byte chunk name
210 * and the 4 byte chunk length before proceeding with decoding the
211 * chunk data. To fully decode each of these chunks, we also make
212 * sure we have enough data in the buffer for the 4 byte CRC at the
213 * end of every chunk (except IDAT, which is handled separately).
214 */
215 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
216 {
217 png_byte chunk_length[4];
218
219 if (png_ptr->buffer_size < 8)
220 {
221 png_push_save_buffer(png_ptr);
222 return;
223 }
224
225 png_push_fill_buffer(png_ptr, chunk_length, 4);
226 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
227 png_reset_crc(png_ptr);
228 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
229 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
230 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
231 }
232
233 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
234 if (png_ptr->mode & PNG_AFTER_IDAT)
235 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
236
237 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
238 {
239 if (png_ptr->push_length != 13)
240 png_error(png_ptr, "Invalid IHDR length");
241
242 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
243 {
244 png_push_save_buffer(png_ptr);
245 return;
246 }
247
248 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
249 }
250
251 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
252 {
253 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
254 {
255 png_push_save_buffer(png_ptr);
256 return;
257 }
258
259 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
260
261 png_ptr->process_mode = PNG_READ_DONE_MODE;
262 png_push_have_end(png_ptr, info_ptr);
263 }
264
265#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
266 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
267 {
268 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
269 {
270 png_push_save_buffer(png_ptr);
271 return;
272 }
273
274 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
275 png_ptr->mode |= PNG_HAVE_IDAT;
276
277 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
278
279 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
280 png_ptr->mode |= PNG_HAVE_PLTE;
281
282 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
283 {
284 if (!(png_ptr->mode & PNG_HAVE_IHDR))
285 png_error(png_ptr, "Missing IHDR before IDAT");
286
287 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
288 !(png_ptr->mode & PNG_HAVE_PLTE))
289 png_error(png_ptr, "Missing PLTE before IDAT");
290 }
291 }
292
293#endif
294 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
295 {
296 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
297 {
298 png_push_save_buffer(png_ptr);
299 return;
300 }
301 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
302 }
303
304 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
305 {
306 /* If we reach an IDAT chunk, this means we have read all of the
307 * header chunks, and we can start reading the image (or if this
308 * is called after the image has been read - we have an error).
309 */
310
311 if (!(png_ptr->mode & PNG_HAVE_IHDR))
312 png_error(png_ptr, "Missing IHDR before IDAT");
313
314 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
315 !(png_ptr->mode & PNG_HAVE_PLTE))
316 png_error(png_ptr, "Missing PLTE before IDAT");
317
318 if (png_ptr->mode & PNG_HAVE_IDAT)
319 {
320 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
321 if (png_ptr->push_length == 0)
322 return;
323
324 if (png_ptr->mode & PNG_AFTER_IDAT)
325 png_error(png_ptr, "Too many IDAT's found");
326 }
327
328 png_ptr->idat_size = png_ptr->push_length;
329 png_ptr->mode |= PNG_HAVE_IDAT;
330 png_ptr->process_mode = PNG_READ_IDAT_MODE;
331 png_push_have_info(png_ptr, info_ptr);
332 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
333 png_ptr->zstream.next_out = png_ptr->row_buf;
334 return;
335 }
336
337#if defined(PNG_READ_gAMA_SUPPORTED)
338 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
339 {
340 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
341 {
342 png_push_save_buffer(png_ptr);
343 return;
344 }
345
346 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
347 }
348
349#endif
350#if defined(PNG_READ_sBIT_SUPPORTED)
351 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
352 {
353 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
354 {
355 png_push_save_buffer(png_ptr);
356 return;
357 }
358
359 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
360 }
361
362#endif
363#if defined(PNG_READ_cHRM_SUPPORTED)
364 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 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
372 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
373 }
374
375#endif
376#if defined(PNG_READ_sRGB_SUPPORTED)
377 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
378 {
379 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
380 {
381 png_push_save_buffer(png_ptr);
382 return;
383 }
384
385 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
386 }
387
388#endif
389#if defined(PNG_READ_iCCP_SUPPORTED)
390 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
391 {
392 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
393 {
394 png_push_save_buffer(png_ptr);
395 return;
396 }
397
398 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
399 }
400
401#endif
402#if defined(PNG_READ_sPLT_SUPPORTED)
403 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
404 {
405 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
406 {
407 png_push_save_buffer(png_ptr);
408 return;
409 }
410
411 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
412 }
413
414#endif
415#if defined(PNG_READ_tRNS_SUPPORTED)
416 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
417 {
418 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
419 {
420 png_push_save_buffer(png_ptr);
421 return;
422 }
423
424 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
425 }
426
427#endif
428#if defined(PNG_READ_bKGD_SUPPORTED)
429 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
430 {
431 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
432 {
433 png_push_save_buffer(png_ptr);
434 return;
435 }
436
437 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
438 }
439
440#endif
441#if defined(PNG_READ_hIST_SUPPORTED)
442 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
443 {
444 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
445 {
446 png_push_save_buffer(png_ptr);
447 return;
448 }
449
450 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
451 }
452
453#endif
454#if defined(PNG_READ_pHYs_SUPPORTED)
455 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
456 {
457 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
458 {
459 png_push_save_buffer(png_ptr);
460 return;
461 }
462
463 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
464 }
465
466#endif
467#if defined(PNG_READ_oFFs_SUPPORTED)
468 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
469 {
470 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
471 {
472 png_push_save_buffer(png_ptr);
473 return;
474 }
475
476 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
477 }
478#endif
479
480#if defined(PNG_READ_pCAL_SUPPORTED)
481 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
482 {
483 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
484 {
485 png_push_save_buffer(png_ptr);
486 return;
487 }
488
489 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
490 }
491
492#endif
493#if defined(PNG_READ_sCAL_SUPPORTED)
494 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
495 {
496 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
497 {
498 png_push_save_buffer(png_ptr);
499 return;
500 }
501
502 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
503 }
504
505#endif
506#if defined(PNG_READ_tIME_SUPPORTED)
507 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
508 {
509 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
510 {
511 png_push_save_buffer(png_ptr);
512 return;
513 }
514
515 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
516 }
517
518#endif
519#if defined(PNG_READ_tEXt_SUPPORTED)
520 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
521 {
522 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
523 {
524 png_push_save_buffer(png_ptr);
525 return;
526 }
527
528 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
529 }
530
531#endif
532#if defined(PNG_READ_zTXt_SUPPORTED)
533 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
534 {
535 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
536 {
537 png_push_save_buffer(png_ptr);
538 return;
539 }
540
541 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
542 }
543
544#endif
545#if defined(PNG_READ_iTXt_SUPPORTED)
546 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
547 {
548 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
549 {
550 png_push_save_buffer(png_ptr);
551 return;
552 }
553
554 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
555 }
556
557#endif
558 else
559 {
560 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
561 {
562 png_push_save_buffer(png_ptr);
563 return;
564 }
565 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
566 }
567
568 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
569}
570
571void /* PRIVATE */
572png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
573{
574 png_ptr->process_mode = PNG_SKIP_MODE;
575 png_ptr->skip_length = skip;
576}
577
578void /* PRIVATE */
579png_push_crc_finish(png_structp png_ptr)
580{
581 if (png_ptr->skip_length && png_ptr->save_buffer_size)
582 {
583 png_size_t save_size;
584
585 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
586 save_size = (png_size_t)png_ptr->skip_length;
587 else
588 save_size = png_ptr->save_buffer_size;
589
590 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
591
592 png_ptr->skip_length -= save_size;
593 png_ptr->buffer_size -= save_size;
594 png_ptr->save_buffer_size -= save_size;
595 png_ptr->save_buffer_ptr += save_size;
596 }
597 if (png_ptr->skip_length && png_ptr->current_buffer_size)
598 {
599 png_size_t save_size;
600
601 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
602 save_size = (png_size_t)png_ptr->skip_length;
603 else
604 save_size = png_ptr->current_buffer_size;
605
606 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
607
608 png_ptr->skip_length -= save_size;
609 png_ptr->buffer_size -= save_size;
610 png_ptr->current_buffer_size -= save_size;
611 png_ptr->current_buffer_ptr += save_size;
612 }
613 if (!png_ptr->skip_length)
614 {
615 if (png_ptr->buffer_size < 4)
616 {
617 png_push_save_buffer(png_ptr);
618 return;
619 }
620
621 png_crc_finish(png_ptr, 0);
622 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
623 }
624}
625
626void PNGAPI
627png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
628{
629 png_bytep ptr;
630
631 if (png_ptr == NULL)
632 return;
633
634 ptr = buffer;
635 if (png_ptr->save_buffer_size)
636 {
637 png_size_t save_size;
638
639 if (length < png_ptr->save_buffer_size)
640 save_size = length;
641 else
642 save_size = png_ptr->save_buffer_size;
643
644 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
645 length -= save_size;
646 ptr += save_size;
647 png_ptr->buffer_size -= save_size;
648 png_ptr->save_buffer_size -= save_size;
649 png_ptr->save_buffer_ptr += save_size;
650 }
651 if (length && png_ptr->current_buffer_size)
652 {
653 png_size_t save_size;
654
655 if (length < png_ptr->current_buffer_size)
656 save_size = length;
657
658 else
659 save_size = png_ptr->current_buffer_size;
660
661 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
662 png_ptr->buffer_size -= save_size;
663 png_ptr->current_buffer_size -= save_size;
664 png_ptr->current_buffer_ptr += save_size;
665 }
666}
667
668void /* PRIVATE */
669png_push_save_buffer(png_structp png_ptr)
670{
671 if (png_ptr->save_buffer_size)
672 {
673 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
674 {
675 png_size_t i, istop;
676 png_bytep sp;
677 png_bytep dp;
678
679 istop = png_ptr->save_buffer_size;
680 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
681 i < istop; i++, sp++, dp++)
682 {
683 *dp = *sp;
684 }
685 }
686 }
687 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
688 png_ptr->save_buffer_max)
689 {
690 png_size_t new_max;
691 png_bytep old_buffer;
692
693 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
694 (png_ptr->current_buffer_size + 256))
695 {
696 png_error(png_ptr, "Potential overflow of save_buffer");
697 }
698
699 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
700 old_buffer = png_ptr->save_buffer;
701 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
702 (png_uint_32)new_max);
703 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
704 png_free(png_ptr, old_buffer);
705 png_ptr->save_buffer_max = new_max;
706 }
707 if (png_ptr->current_buffer_size)
708 {
709 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
710 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
711 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
712 png_ptr->current_buffer_size = 0;
713 }
714 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
715 png_ptr->buffer_size = 0;
716}
717
718void /* PRIVATE */
719png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
720 png_size_t buffer_length)
721{
722 png_ptr->current_buffer = buffer;
723 png_ptr->current_buffer_size = buffer_length;
724 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
725 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
726}
727
728void /* PRIVATE */
729png_push_read_IDAT(png_structp png_ptr)
730{
731#ifdef PNG_USE_LOCAL_ARRAYS
732 PNG_CONST PNG_IDAT;
733#endif
734 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
735 {
736 png_byte chunk_length[4];
737
738 if (png_ptr->buffer_size < 8)
739 {
740 png_push_save_buffer(png_ptr);
741 return;
742 }
743
744 png_push_fill_buffer(png_ptr, chunk_length, 4);
745 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
746 png_reset_crc(png_ptr);
747 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
748 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
749
750 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
751 {
752 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
753 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
754 png_error(png_ptr, "Not enough compressed data");
755 return;
756 }
757
758 png_ptr->idat_size = png_ptr->push_length;
759 }
760 if (png_ptr->idat_size && png_ptr->save_buffer_size)
761 {
762 png_size_t save_size;
763
764 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
765 {
766 save_size = (png_size_t)png_ptr->idat_size;
767
768 /* Check for overflow */
769 if ((png_uint_32)save_size != png_ptr->idat_size)
770 png_error(png_ptr, "save_size overflowed in pngpread");
771 }
772 else
773 save_size = png_ptr->save_buffer_size;
774
775 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
776
777 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
778 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
779
780 png_ptr->idat_size -= save_size;
781 png_ptr->buffer_size -= save_size;
782 png_ptr->save_buffer_size -= save_size;
783 png_ptr->save_buffer_ptr += save_size;
784 }
785 if (png_ptr->idat_size && png_ptr->current_buffer_size)
786 {
787 png_size_t save_size;
788
789 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
790 {
791 save_size = (png_size_t)png_ptr->idat_size;
792
793 /* Check for overflow */
794 if ((png_uint_32)save_size != png_ptr->idat_size)
795 png_error(png_ptr, "save_size overflowed in pngpread");
796 }
797 else
798 save_size = png_ptr->current_buffer_size;
799
800 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
801 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
802 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
803
804 png_ptr->idat_size -= save_size;
805 png_ptr->buffer_size -= save_size;
806 png_ptr->current_buffer_size -= save_size;
807 png_ptr->current_buffer_ptr += save_size;
808 }
809 if (!png_ptr->idat_size)
810 {
811 if (png_ptr->buffer_size < 4)
812 {
813 png_push_save_buffer(png_ptr);
814 return;
815 }
816
817 png_crc_finish(png_ptr, 0);
818 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
819 png_ptr->mode |= PNG_AFTER_IDAT;
820 }
821}
822
823void /* PRIVATE */
824png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
825 png_size_t buffer_length)
826{
827 int ret;
828
829 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
830 png_error(png_ptr, "Extra compression data");
831
832 png_ptr->zstream.next_in = buffer;
833 png_ptr->zstream.avail_in = (uInt)buffer_length;
834 for (;;)
835 {
836 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
837 if (ret != Z_OK)
838 {
839 if (ret == Z_STREAM_END)
840 {
841 if (png_ptr->zstream.avail_in)
842 png_error(png_ptr, "Extra compressed data");
843
844 if (!(png_ptr->zstream.avail_out))
845 {
846 png_push_process_row(png_ptr);
847 }
848
849 png_ptr->mode |= PNG_AFTER_IDAT;
850 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
851 break;
852 }
853 else if (ret == Z_BUF_ERROR)
854 break;
855
856 else
857 png_error(png_ptr, "Decompression Error");
858 }
859 if (!(png_ptr->zstream.avail_out))
860 {
861 if ((
862#if defined(PNG_READ_INTERLACING_SUPPORTED)
863 png_ptr->interlaced && png_ptr->pass > 6) ||
864 (!png_ptr->interlaced &&
865#endif
866 png_ptr->row_number == png_ptr->num_rows))
867 {
868 if (png_ptr->zstream.avail_in)
869 png_warning(png_ptr, "Too much data in IDAT chunks");
870 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
871 break;
872 }
873 png_push_process_row(png_ptr);
874 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
875 png_ptr->zstream.next_out = png_ptr->row_buf;
876 }
877
878 else
879 break;
880 }
881}
882
883void /* PRIVATE */
884png_push_process_row(png_structp png_ptr)
885{
886 png_ptr->row_info.color_type = png_ptr->color_type;
887 png_ptr->row_info.width = png_ptr->iwidth;
888 png_ptr->row_info.channels = png_ptr->channels;
889 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
890 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
891
892 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
893 png_ptr->row_info.width);
894
895 png_read_filter_row(png_ptr, &(png_ptr->row_info),
896 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
897 (int)(png_ptr->row_buf[0]));
898
899 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
900 png_ptr->rowbytes + 1);
901
902 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
903 png_do_read_transformations(png_ptr);
904
905#if defined(PNG_READ_INTERLACING_SUPPORTED)
906 /* Blow up interlaced rows to full size */
907 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
908 {
909 if (png_ptr->pass < 6)
910/* old interface (pre-1.0.9):
911 png_do_read_interlace(&(png_ptr->row_info),
912 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
913 */
914 png_do_read_interlace(png_ptr);
915
916 switch (png_ptr->pass)
917 {
918 case 0:
919 {
920 int i;
921 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
922 {
923 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
924 png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
925 }
926
927 if (png_ptr->pass == 2) /* Pass 1 might be empty */
928 {
929 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
930 {
931 png_push_have_row(png_ptr, png_bytep_NULL);
932 png_read_push_finish_row(png_ptr);
933 }
934 }
935
936 if (png_ptr->pass == 4 && png_ptr->height <= 4)
937 {
938 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
939 {
940 png_push_have_row(png_ptr, png_bytep_NULL);
941 png_read_push_finish_row(png_ptr);
942 }
943 }
944
945 if (png_ptr->pass == 6 && png_ptr->height <= 4)
946 {
947 png_push_have_row(png_ptr, png_bytep_NULL);
948 png_read_push_finish_row(png_ptr);
949 }
950
951 break;
952 }
953
954 case 1:
955 {
956 int i;
957 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
958 {
959 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
960 png_read_push_finish_row(png_ptr);
961 }
962
963 if (png_ptr->pass == 2) /* Skip top 4 generated rows */
964 {
965 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
966 {
967 png_push_have_row(png_ptr, png_bytep_NULL);
968 png_read_push_finish_row(png_ptr);
969 }
970 }
971
972 break;
973 }
974
975 case 2:
976 {
977 int i;
978
979 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
980 {
981 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
982 png_read_push_finish_row(png_ptr);
983 }
984
985 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
986 {
987 png_push_have_row(png_ptr, png_bytep_NULL);
988 png_read_push_finish_row(png_ptr);
989 }
990
991 if (png_ptr->pass == 4) /* Pass 3 might be empty */
992 {
993 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
994 {
995 png_push_have_row(png_ptr, png_bytep_NULL);
996 png_read_push_finish_row(png_ptr);
997 }
998 }
999
1000 break;
1001 }
1002
1003 case 3:
1004 {
1005 int i;
1006
1007 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
1008 {
1009 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1010 png_read_push_finish_row(png_ptr);
1011 }
1012
1013 if (png_ptr->pass == 4) /* Skip top two generated rows */
1014 {
1015 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1016 {
1017 png_push_have_row(png_ptr, png_bytep_NULL);
1018 png_read_push_finish_row(png_ptr);
1019 }
1020 }
1021
1022 break;
1023 }
1024
1025 case 4:
1026 {
1027 int i;
1028
1029 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1030 {
1031 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1032 png_read_push_finish_row(png_ptr);
1033 }
1034
1035 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1036 {
1037 png_push_have_row(png_ptr, png_bytep_NULL);
1038 png_read_push_finish_row(png_ptr);
1039 }
1040
1041 if (png_ptr->pass == 6) /* Pass 5 might be empty */
1042 {
1043 png_push_have_row(png_ptr, png_bytep_NULL);
1044 png_read_push_finish_row(png_ptr);
1045 }
1046
1047 break;
1048 }
1049
1050 case 5:
1051 {
1052 int i;
1053
1054 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1055 {
1056 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1057 png_read_push_finish_row(png_ptr);
1058 }
1059
1060 if (png_ptr->pass == 6) /* Skip top generated row */
1061 {
1062 png_push_have_row(png_ptr, png_bytep_NULL);
1063 png_read_push_finish_row(png_ptr);
1064 }
1065
1066 break;
1067 }
1068 case 6:
1069 {
1070 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1071 png_read_push_finish_row(png_ptr);
1072
1073 if (png_ptr->pass != 6)
1074 break;
1075
1076 png_push_have_row(png_ptr, png_bytep_NULL);
1077 png_read_push_finish_row(png_ptr);
1078 }
1079 }
1080 }
1081 else
1082#endif
1083 {
1084 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1085 png_read_push_finish_row(png_ptr);
1086 }
1087}
1088
1089void /* PRIVATE */
1090png_read_push_finish_row(png_structp png_ptr)
1091{
1092#ifdef PNG_USE_LOCAL_ARRAYS
1093 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1094
1095 /* Start of interlace block */
1096 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1097
1098 /* Offset to next interlace block */
1099 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1100
1101 /* Start of interlace block in the y direction */
1102 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1103
1104 /* Offset to next interlace block in the y direction */
1105 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1106
1107 /* Height of interlace block. This is not currently used - if you need
1108 * it, uncomment it here and in png.h
1109 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1110 */
1111#endif
1112
1113 png_ptr->row_number++;
1114 if (png_ptr->row_number < png_ptr->num_rows)
1115 return;
1116
1117#if defined(PNG_READ_INTERLACING_SUPPORTED)
1118 if (png_ptr->interlaced)
1119 {
1120 png_ptr->row_number = 0;
1121 png_memset_check(png_ptr, png_ptr->prev_row, 0,
1122 png_ptr->rowbytes + 1);
1123 do
1124 {
1125 png_ptr->pass++;
1126 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1127 (png_ptr->pass == 3 && png_ptr->width < 3) ||
1128 (png_ptr->pass == 5 && png_ptr->width < 2))
1129 png_ptr->pass++;
1130
1131 if (png_ptr->pass > 7)
1132 png_ptr->pass--;
1133
1134 if (png_ptr->pass >= 7)
1135 break;
1136
1137 png_ptr->iwidth = (png_ptr->width +
1138 png_pass_inc[png_ptr->pass] - 1 -
1139 png_pass_start[png_ptr->pass]) /
1140 png_pass_inc[png_ptr->pass];
1141
1142 png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
1143 png_ptr->iwidth) + 1;
1144
1145 if (png_ptr->transformations & PNG_INTERLACE)
1146 break;
1147
1148 png_ptr->num_rows = (png_ptr->height +
1149 png_pass_yinc[png_ptr->pass] - 1 -
1150 png_pass_ystart[png_ptr->pass]) /
1151 png_pass_yinc[png_ptr->pass];
1152
1153 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1154 }
1155#endif /* PNG_READ_INTERLACING_SUPPORTED */
1156}
1157
1158#if defined(PNG_READ_tEXt_SUPPORTED)
1159void /* PRIVATE */
1160png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1161 length)
1162{
1163 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1164 {
1165 png_error(png_ptr, "Out of place tEXt");
1166 info_ptr = info_ptr; /* To quiet some compiler warnings */
1167 }
1168
1169#ifdef PNG_MAX_MALLOC_64K
1170 png_ptr->skip_length = 0; /* This may not be necessary */
1171
1172 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1173 {
1174 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1175 png_ptr->skip_length = length - (png_uint_32)65535L;
1176 length = (png_uint_32)65535L;
1177 }
1178#endif
1179
1180 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1181 (png_uint_32)(length + 1));
1182 png_ptr->current_text[length] = '\0';
1183 png_ptr->current_text_ptr = png_ptr->current_text;
1184 png_ptr->current_text_size = (png_size_t)length;
1185 png_ptr->current_text_left = (png_size_t)length;
1186 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1187}
1188
1189void /* PRIVATE */
1190png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1191{
1192 if (png_ptr->buffer_size && png_ptr->current_text_left)
1193 {
1194 png_size_t text_size;
1195
1196 if (png_ptr->buffer_size < png_ptr->current_text_left)
1197 text_size = png_ptr->buffer_size;
1198
1199 else
1200 text_size = png_ptr->current_text_left;
1201
1202 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1203 png_ptr->current_text_left -= text_size;
1204 png_ptr->current_text_ptr += text_size;
1205 }
1206 if (!(png_ptr->current_text_left))
1207 {
1208 png_textp text_ptr;
1209 png_charp text;
1210 png_charp key;
1211 int ret;
1212
1213 if (png_ptr->buffer_size < 4)
1214 {
1215 png_push_save_buffer(png_ptr);
1216 return;
1217 }
1218
1219 png_push_crc_finish(png_ptr);
1220
1221#if defined(PNG_MAX_MALLOC_64K)
1222 if (png_ptr->skip_length)
1223 return;
1224#endif
1225
1226 key = png_ptr->current_text;
1227
1228 for (text = key; *text; text++)
1229 /* Empty loop */ ;
1230
1231 if (text < key + png_ptr->current_text_size)
1232 text++;
1233
1234 text_ptr = (png_textp)png_malloc(png_ptr,
1235 (png_uint_32)png_sizeof(png_text));
1236 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1237 text_ptr->key = key;
1238#ifdef PNG_iTXt_SUPPORTED
1239 text_ptr->lang = NULL;
1240 text_ptr->lang_key = NULL;
1241#endif
1242 text_ptr->text = text;
1243
1244 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1245
1246 png_free(png_ptr, key);
1247 png_free(png_ptr, text_ptr);
1248 png_ptr->current_text = NULL;
1249
1250 if (ret)
1251 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1252 }
1253}
1254#endif
1255
1256#if defined(PNG_READ_zTXt_SUPPORTED)
1257void /* PRIVATE */
1258png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1259 length)
1260{
1261 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1262 {
1263 png_error(png_ptr, "Out of place zTXt");
1264 info_ptr = info_ptr; /* To quiet some compiler warnings */
1265 }
1266
1267#ifdef PNG_MAX_MALLOC_64K
1268 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1269 * to be able to store the uncompressed data. Actually, the threshold
1270 * is probably around 32K, but it isn't as definite as 64K is.
1271 */
1272 if (length > (png_uint_32)65535L)
1273 {
1274 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1275 png_push_crc_skip(png_ptr, length);
1276 return;
1277 }
1278#endif
1279
1280 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1281 (png_uint_32)(length + 1));
1282 png_ptr->current_text[length] = '\0';
1283 png_ptr->current_text_ptr = png_ptr->current_text;
1284 png_ptr->current_text_size = (png_size_t)length;
1285 png_ptr->current_text_left = (png_size_t)length;
1286 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1287}
1288
1289void /* PRIVATE */
1290png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1291{
1292 if (png_ptr->buffer_size && png_ptr->current_text_left)
1293 {
1294 png_size_t text_size;
1295
1296 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1297 text_size = png_ptr->buffer_size;
1298
1299 else
1300 text_size = png_ptr->current_text_left;
1301
1302 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1303 png_ptr->current_text_left -= text_size;
1304 png_ptr->current_text_ptr += text_size;
1305 }
1306 if (!(png_ptr->current_text_left))
1307 {
1308 png_textp text_ptr;
1309 png_charp text;
1310 png_charp key;
1311 int ret;
1312 png_size_t text_size, key_size;
1313
1314 if (png_ptr->buffer_size < 4)
1315 {
1316 png_push_save_buffer(png_ptr);
1317 return;
1318 }
1319
1320 png_push_crc_finish(png_ptr);
1321
1322 key = png_ptr->current_text;
1323
1324 for (text = key; *text; text++)
1325 /* Empty loop */ ;
1326
1327 /* zTXt can't have zero text */
1328 if (text >= key + png_ptr->current_text_size)
1329 {
1330 png_ptr->current_text = NULL;
1331 png_free(png_ptr, key);
1332 return;
1333 }
1334
1335 text++;
1336
1337 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1338 {
1339 png_ptr->current_text = NULL;
1340 png_free(png_ptr, key);
1341 return;
1342 }
1343
1344 text++;
1345
1346 png_ptr->zstream.next_in = (png_bytep )text;
1347 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1348 (text - key));
1349 png_ptr->zstream.next_out = png_ptr->zbuf;
1350 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1351
1352 key_size = text - key;
1353 text_size = 0;
1354 text = NULL;
1355 ret = Z_STREAM_END;
1356
1357 while (png_ptr->zstream.avail_in)
1358 {
1359 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1360 if (ret != Z_OK && ret != Z_STREAM_END)
1361 {
1362 inflateReset(&png_ptr->zstream);
1363 png_ptr->zstream.avail_in = 0;
1364 png_ptr->current_text = NULL;
1365 png_free(png_ptr, key);
1366 png_free(png_ptr, text);
1367 return;
1368 }
1369 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1370 {
1371 if (text == NULL)
1372 {
1373 text = (png_charp)png_malloc(png_ptr,
1374 (png_uint_32)(png_ptr->zbuf_size
1375 - png_ptr->zstream.avail_out + key_size + 1));
1376
1377 png_memcpy(text + key_size, png_ptr->zbuf,
1378 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1379
1380 png_memcpy(text, key, key_size);
1381
1382 text_size = key_size + png_ptr->zbuf_size -
1383 png_ptr->zstream.avail_out;
1384
1385 *(text + text_size) = '\0';
1386 }
1387 else
1388 {
1389 png_charp tmp;
1390
1391 tmp = text;
1392 text = (png_charp)png_malloc(png_ptr, text_size +
1393 (png_uint_32)(png_ptr->zbuf_size
1394 - png_ptr->zstream.avail_out + 1));
1395
1396 png_memcpy(text, tmp, text_size);
1397 png_free(png_ptr, tmp);
1398
1399 png_memcpy(text + text_size, png_ptr->zbuf,
1400 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1401
1402 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1403 *(text + text_size) = '\0';
1404 }
1405 if (ret != Z_STREAM_END)
1406 {
1407 png_ptr->zstream.next_out = png_ptr->zbuf;
1408 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1409 }
1410 }
1411 else
1412 {
1413 break;
1414 }
1415
1416 if (ret == Z_STREAM_END)
1417 break;
1418 }
1419
1420 inflateReset(&png_ptr->zstream);
1421 png_ptr->zstream.avail_in = 0;
1422
1423 if (ret != Z_STREAM_END)
1424 {
1425 png_ptr->current_text = NULL;
1426 png_free(png_ptr, key);
1427 png_free(png_ptr, text);
1428 return;
1429 }
1430
1431 png_ptr->current_text = NULL;
1432 png_free(png_ptr, key);
1433 key = text;
1434 text += key_size;
1435
1436 text_ptr = (png_textp)png_malloc(png_ptr,
1437 (png_uint_32)png_sizeof(png_text));
1438 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1439 text_ptr->key = key;
1440#ifdef PNG_iTXt_SUPPORTED
1441 text_ptr->lang = NULL;
1442 text_ptr->lang_key = NULL;
1443#endif
1444 text_ptr->text = text;
1445
1446 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1447
1448 png_free(png_ptr, key);
1449 png_free(png_ptr, text_ptr);
1450
1451 if (ret)
1452 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1453 }
1454}
1455#endif
1456
1457#if defined(PNG_READ_iTXt_SUPPORTED)
1458void /* PRIVATE */
1459png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1460 length)
1461{
1462 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1463 {
1464 png_error(png_ptr, "Out of place iTXt");
1465 info_ptr = info_ptr; /* To quiet some compiler warnings */
1466 }
1467
1468#ifdef PNG_MAX_MALLOC_64K
1469 png_ptr->skip_length = 0; /* This may not be necessary */
1470
1471 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1472 {
1473 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1474 png_ptr->skip_length = length - (png_uint_32)65535L;
1475 length = (png_uint_32)65535L;
1476 }
1477#endif
1478
1479 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1480 (png_uint_32)(length + 1));
1481 png_ptr->current_text[length] = '\0';
1482 png_ptr->current_text_ptr = png_ptr->current_text;
1483 png_ptr->current_text_size = (png_size_t)length;
1484 png_ptr->current_text_left = (png_size_t)length;
1485 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1486}
1487
1488void /* PRIVATE */
1489png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1490{
1491
1492 if (png_ptr->buffer_size && png_ptr->current_text_left)
1493 {
1494 png_size_t text_size;
1495
1496 if (png_ptr->buffer_size < png_ptr->current_text_left)
1497 text_size = png_ptr->buffer_size;
1498
1499 else
1500 text_size = png_ptr->current_text_left;
1501
1502 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1503 png_ptr->current_text_left -= text_size;
1504 png_ptr->current_text_ptr += text_size;
1505 }
1506 if (!(png_ptr->current_text_left))
1507 {
1508 png_textp text_ptr;
1509 png_charp key;
1510 int comp_flag;
1511 png_charp lang;
1512 png_charp lang_key;
1513 png_charp text;
1514 int ret;
1515
1516 if (png_ptr->buffer_size < 4)
1517 {
1518 png_push_save_buffer(png_ptr);
1519 return;
1520 }
1521
1522 png_push_crc_finish(png_ptr);
1523
1524#if defined(PNG_MAX_MALLOC_64K)
1525 if (png_ptr->skip_length)
1526 return;
1527#endif
1528
1529 key = png_ptr->current_text;
1530
1531 for (lang = key; *lang; lang++)
1532 /* Empty loop */ ;
1533
1534 if (lang < key + png_ptr->current_text_size - 3)
1535 lang++;
1536
1537 comp_flag = *lang++;
1538 lang++; /* Skip comp_type, always zero */
1539
1540 for (lang_key = lang; *lang_key; lang_key++)
1541 /* Empty loop */ ;
1542
1543 lang_key++; /* Skip NUL separator */
1544
1545 text=lang_key;
1546
1547 if (lang_key < key + png_ptr->current_text_size - 1)
1548 {
1549 for (; *text; text++)
1550 /* Empty loop */ ;
1551 }
1552
1553 if (text < key + png_ptr->current_text_size)
1554 text++;
1555
1556 text_ptr = (png_textp)png_malloc(png_ptr,
1557 (png_uint_32)png_sizeof(png_text));
1558
1559 text_ptr->compression = comp_flag + 2;
1560 text_ptr->key = key;
1561 text_ptr->lang = lang;
1562 text_ptr->lang_key = lang_key;
1563 text_ptr->text = text;
1564 text_ptr->text_length = 0;
1565 text_ptr->itxt_length = png_strlen(text);
1566
1567 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1568
1569 png_ptr->current_text = NULL;
1570
1571 png_free(png_ptr, text_ptr);
1572 if (ret)
1573 png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1574 }
1575}
1576#endif
1577
1578/* This function is called when we haven't found a handler for this
1579 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1580 * name or a critical chunk), the chunk is (currently) silently ignored.
1581 */
1582void /* PRIVATE */
1583png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1584 length)
1585{
1586 png_uint_32 skip = 0;
1587
1588 if (!(png_ptr->chunk_name[0] & 0x20))
1589 {
1590#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1591 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1592 PNG_HANDLE_CHUNK_ALWAYS
1593#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1594 && png_ptr->read_user_chunk_fn == NULL
1595#endif
1596 )
1597#endif
1598 png_chunk_error(png_ptr, "unknown critical chunk");
1599
1600 info_ptr = info_ptr; /* To quiet some compiler warnings */
1601 }
1602
1603#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1604 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1605 {
1606#ifdef PNG_MAX_MALLOC_64K
1607 if (length > (png_uint_32)65535L)
1608 {
1609 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1610 skip = length - (png_uint_32)65535L;
1611 length = (png_uint_32)65535L;
1612 }
1613#endif
1614 png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1615 (png_charp)png_ptr->chunk_name,
1616 png_sizeof(png_ptr->unknown_chunk.name));
1617 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
1618 = '\0';
1619
1620 png_ptr->unknown_chunk.size = (png_size_t)length;
1621
1622 if (length == 0)
1623 png_ptr->unknown_chunk.data = NULL;
1624
1625 else
1626 {
1627 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1628 (png_uint_32)length);
1629 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1630 }
1631
1632#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1633 if (png_ptr->read_user_chunk_fn != NULL)
1634 {
1635 /* Callback to user unknown chunk handler */
1636 int ret;
1637 ret = (*(png_ptr->read_user_chunk_fn))
1638 (png_ptr, &png_ptr->unknown_chunk);
1639
1640 if (ret < 0)
1641 png_chunk_error(png_ptr, "error in user chunk");
1642
1643 if (ret == 0)
1644 {
1645 if (!(png_ptr->chunk_name[0] & 0x20))
1646 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1647 PNG_HANDLE_CHUNK_ALWAYS)
1648 png_chunk_error(png_ptr, "unknown critical chunk");
1649 png_set_unknown_chunks(png_ptr, info_ptr,
1650 &png_ptr->unknown_chunk, 1);
1651 }
1652 }
1653
1654 else
1655#endif
1656 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1657 png_free(png_ptr, png_ptr->unknown_chunk.data);
1658 png_ptr->unknown_chunk.data = NULL;
1659 }
1660
1661 else
1662#endif
1663 skip=length;
1664 png_push_crc_skip(png_ptr, skip);
1665}
1666
1667void /* PRIVATE */
1668png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1669{
1670 if (png_ptr->info_fn != NULL)
1671 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1672}
1673
1674void /* PRIVATE */
1675png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1676{
1677 if (png_ptr->end_fn != NULL)
1678 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1679}
1680
1681void /* PRIVATE */
1682png_push_have_row(png_structp png_ptr, png_bytep row)
1683{
1684 if (png_ptr->row_fn != NULL)
1685 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1686 (int)png_ptr->pass);
1687}
1688
1689void PNGAPI
1690png_progressive_combine_row (png_structp png_ptr,
1691 png_bytep old_row, png_bytep new_row)
1692{
1693#ifdef PNG_USE_LOCAL_ARRAYS
1694 PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1695 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1696#endif
1697 if (png_ptr == NULL)
1698 return;
1699
1700 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1701 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1702}
1703
1704void PNGAPI
1705png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1706 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1707 png_progressive_end_ptr end_fn)
1708{
1709 if (png_ptr == NULL)
1710 return;
1711
1712 png_ptr->info_fn = info_fn;
1713 png_ptr->row_fn = row_fn;
1714 png_ptr->end_fn = end_fn;
1715
1716 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1717}
1718
1719png_voidp PNGAPI
1720png_get_progressive_ptr(png_structp png_ptr)
1721{
1722 if (png_ptr == NULL)
1723 return (NULL);
1724
1725 return png_ptr->io_ptr;
1726}
1727#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
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