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-rw-r--r--libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c1843
1 files changed, 1843 insertions, 0 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c
new file mode 100644
index 0000000..eda5a6c
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+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c
@@ -0,0 +1,1843 @@
1
2/* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.5.9 [February 18, 2012]
5 * Copyright (c) 1998-2011 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
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
44png_size_t PNGAPI
45png_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
71png_uint_32 PNGAPI
72png_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 */
105void /* PRIVATE */
106png_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#ifdef PNG_READ_tEXt_SUPPORTED
132 case PNG_READ_tEXt_MODE:
133 {
134 png_push_read_tEXt(png_ptr, info_ptr);
135 break;
136 }
137
138#endif
139#ifdef PNG_READ_zTXt_SUPPORTED
140 case PNG_READ_zTXt_MODE:
141 {
142 png_push_read_zTXt(png_ptr, info_ptr);
143 break;
144 }
145
146#endif
147#ifdef PNG_READ_iTXt_SUPPORTED
148 case PNG_READ_iTXt_MODE:
149 {
150 png_push_read_iTXt(png_ptr, info_ptr);
151 break;
152 }
153
154#endif
155 case PNG_SKIP_MODE:
156 {
157 png_push_crc_finish(png_ptr);
158 break;
159 }
160
161 default:
162 {
163 png_ptr->buffer_size = 0;
164 break;
165 }
166 }
167}
168
169/* Read any remaining signature bytes from the stream and compare them with
170 * the correct PNG signature. It is possible that this routine is called
171 * with bytes already read from the signature, either because they have been
172 * checked by the calling application, or because of multiple calls to this
173 * routine.
174 */
175void /* PRIVATE */
176png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
177{
178 png_size_t num_checked = png_ptr->sig_bytes,
179 num_to_check = 8 - num_checked;
180
181 if (png_ptr->buffer_size < num_to_check)
182 {
183 num_to_check = png_ptr->buffer_size;
184 }
185
186 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
187 num_to_check);
188 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
189
190 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
191 {
192 if (num_checked < 4 &&
193 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
194 png_error(png_ptr, "Not a PNG file");
195
196 else
197 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
198 }
199 else
200 {
201 if (png_ptr->sig_bytes >= 8)
202 {
203 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
204 }
205 }
206}
207
208void /* PRIVATE */
209png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
210{
211 png_uint_32 chunk_name;
212
213 /* First we make sure we have enough data for the 4 byte chunk name
214 * and the 4 byte chunk length before proceeding with decoding the
215 * chunk data. To fully decode each of these chunks, we also make
216 * sure we have enough data in the buffer for the 4 byte CRC at the
217 * end of every chunk (except IDAT, which is handled separately).
218 */
219 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
220 {
221 png_byte chunk_length[4];
222 png_byte chunk_tag[4];
223
224 if (png_ptr->buffer_size < 8)
225 {
226 png_push_save_buffer(png_ptr);
227 return;
228 }
229
230 png_push_fill_buffer(png_ptr, chunk_length, 4);
231 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
232 png_reset_crc(png_ptr);
233 png_crc_read(png_ptr, chunk_tag, 4);
234 png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
235 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
236 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
237 }
238
239 chunk_name = png_ptr->chunk_name;
240
241 if (chunk_name == png_IDAT)
242 {
243 /* This is here above the if/else case statement below because if the
244 * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
245 * completely skipped.
246 *
247 * TODO: there must be a better way of doing this.
248 */
249 if (png_ptr->mode & PNG_AFTER_IDAT)
250 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
251 }
252
253 if (chunk_name == png_IHDR)
254 {
255 if (png_ptr->push_length != 13)
256 png_error(png_ptr, "Invalid IHDR length");
257
258 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
259 {
260 png_push_save_buffer(png_ptr);
261 return;
262 }
263
264 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
265 }
266
267 else if (chunk_name == png_IEND)
268 {
269 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
270 {
271 png_push_save_buffer(png_ptr);
272 return;
273 }
274
275 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
276
277 png_ptr->process_mode = PNG_READ_DONE_MODE;
278 png_push_have_end(png_ptr, info_ptr);
279 }
280
281#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
282 else if (png_chunk_unknown_handling(png_ptr, chunk_name))
283 {
284 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
285 {
286 png_push_save_buffer(png_ptr);
287 return;
288 }
289
290 if (chunk_name == png_IDAT)
291 png_ptr->mode |= PNG_HAVE_IDAT;
292
293 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
294
295 if (chunk_name == png_PLTE)
296 png_ptr->mode |= PNG_HAVE_PLTE;
297
298 else if (chunk_name == png_IDAT)
299 {
300 if (!(png_ptr->mode & PNG_HAVE_IHDR))
301 png_error(png_ptr, "Missing IHDR before IDAT");
302
303 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
304 !(png_ptr->mode & PNG_HAVE_PLTE))
305 png_error(png_ptr, "Missing PLTE before IDAT");
306 }
307 }
308
309#endif
310 else if (chunk_name == png_PLTE)
311 {
312 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
313 {
314 png_push_save_buffer(png_ptr);
315 return;
316 }
317 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
318 }
319
320 else if (chunk_name == png_IDAT)
321 {
322 /* If we reach an IDAT chunk, this means we have read all of the
323 * header chunks, and we can start reading the image (or if this
324 * is called after the image has been read - we have an error).
325 */
326
327 if (!(png_ptr->mode & PNG_HAVE_IHDR))
328 png_error(png_ptr, "Missing IHDR before IDAT");
329
330 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
331 !(png_ptr->mode & PNG_HAVE_PLTE))
332 png_error(png_ptr, "Missing PLTE before IDAT");
333
334 if (png_ptr->mode & PNG_HAVE_IDAT)
335 {
336 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
337 if (png_ptr->push_length == 0)
338 return;
339
340 if (png_ptr->mode & PNG_AFTER_IDAT)
341 png_benign_error(png_ptr, "Too many IDATs found");
342 }
343
344 png_ptr->idat_size = png_ptr->push_length;
345 png_ptr->mode |= PNG_HAVE_IDAT;
346 png_ptr->process_mode = PNG_READ_IDAT_MODE;
347 png_push_have_info(png_ptr, info_ptr);
348 png_ptr->zstream.avail_out =
349 (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
350 png_ptr->iwidth) + 1;
351 png_ptr->zstream.next_out = png_ptr->row_buf;
352 return;
353 }
354
355#ifdef PNG_READ_gAMA_SUPPORTED
356 else if (png_ptr->chunk_name == png_gAMA)
357 {
358 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
359 {
360 png_push_save_buffer(png_ptr);
361 return;
362 }
363
364 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
365 }
366
367#endif
368#ifdef PNG_READ_sBIT_SUPPORTED
369 else if (png_ptr->chunk_name == png_sBIT)
370 {
371 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
372 {
373 png_push_save_buffer(png_ptr);
374 return;
375 }
376
377 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
378 }
379
380#endif
381#ifdef PNG_READ_cHRM_SUPPORTED
382 else if (png_ptr->chunk_name == png_cHRM)
383 {
384 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
385 {
386 png_push_save_buffer(png_ptr);
387 return;
388 }
389
390 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
391 }
392
393#endif
394#ifdef PNG_READ_sRGB_SUPPORTED
395 else if (chunk_name == png_sRGB)
396 {
397 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
398 {
399 png_push_save_buffer(png_ptr);
400 return;
401 }
402
403 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
404 }
405
406#endif
407#ifdef PNG_READ_iCCP_SUPPORTED
408 else if (png_ptr->chunk_name == png_iCCP)
409 {
410 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
411 {
412 png_push_save_buffer(png_ptr);
413 return;
414 }
415
416 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
417 }
418
419#endif
420#ifdef PNG_READ_sPLT_SUPPORTED
421 else if (chunk_name == png_sPLT)
422 {
423 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
424 {
425 png_push_save_buffer(png_ptr);
426 return;
427 }
428
429 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
430 }
431
432#endif
433#ifdef PNG_READ_tRNS_SUPPORTED
434 else if (chunk_name == png_tRNS)
435 {
436 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
437 {
438 png_push_save_buffer(png_ptr);
439 return;
440 }
441
442 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
443 }
444
445#endif
446#ifdef PNG_READ_bKGD_SUPPORTED
447 else if (chunk_name == png_bKGD)
448 {
449 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
450 {
451 png_push_save_buffer(png_ptr);
452 return;
453 }
454
455 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
456 }
457
458#endif
459#ifdef PNG_READ_hIST_SUPPORTED
460 else if (chunk_name == png_hIST)
461 {
462 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
463 {
464 png_push_save_buffer(png_ptr);
465 return;
466 }
467
468 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
469 }
470
471#endif
472#ifdef PNG_READ_pHYs_SUPPORTED
473 else if (chunk_name == png_pHYs)
474 {
475 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
476 {
477 png_push_save_buffer(png_ptr);
478 return;
479 }
480
481 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
482 }
483
484#endif
485#ifdef PNG_READ_oFFs_SUPPORTED
486 else if (chunk_name == png_oFFs)
487 {
488 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
489 {
490 png_push_save_buffer(png_ptr);
491 return;
492 }
493
494 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
495 }
496#endif
497
498#ifdef PNG_READ_pCAL_SUPPORTED
499 else if (chunk_name == png_pCAL)
500 {
501 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
502 {
503 png_push_save_buffer(png_ptr);
504 return;
505 }
506
507 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
508 }
509
510#endif
511#ifdef PNG_READ_sCAL_SUPPORTED
512 else if (chunk_name == png_sCAL)
513 {
514 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
515 {
516 png_push_save_buffer(png_ptr);
517 return;
518 }
519
520 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
521 }
522
523#endif
524#ifdef PNG_READ_tIME_SUPPORTED
525 else if (chunk_name == png_tIME)
526 {
527 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
528 {
529 png_push_save_buffer(png_ptr);
530 return;
531 }
532
533 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
534 }
535
536#endif
537#ifdef PNG_READ_tEXt_SUPPORTED
538 else if (chunk_name == png_tEXt)
539 {
540 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
541 {
542 png_push_save_buffer(png_ptr);
543 return;
544 }
545
546 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
547 }
548
549#endif
550#ifdef PNG_READ_zTXt_SUPPORTED
551 else if (chunk_name == png_zTXt)
552 {
553 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
554 {
555 png_push_save_buffer(png_ptr);
556 return;
557 }
558
559 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
560 }
561
562#endif
563#ifdef PNG_READ_iTXt_SUPPORTED
564 else if (chunk_name == png_iTXt)
565 {
566 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
567 {
568 png_push_save_buffer(png_ptr);
569 return;
570 }
571
572 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
573 }
574
575#endif
576 else
577 {
578 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
579 {
580 png_push_save_buffer(png_ptr);
581 return;
582 }
583 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
584 }
585
586 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
587}
588
589void /* PRIVATE */
590png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
591{
592 png_ptr->process_mode = PNG_SKIP_MODE;
593 png_ptr->skip_length = skip;
594}
595
596void /* PRIVATE */
597png_push_crc_finish(png_structp png_ptr)
598{
599 if (png_ptr->skip_length && png_ptr->save_buffer_size)
600 {
601 png_size_t save_size = png_ptr->save_buffer_size;
602 png_uint_32 skip_length = png_ptr->skip_length;
603
604 /* We want the smaller of 'skip_length' and 'save_buffer_size', but
605 * they are of different types and we don't know which variable has the
606 * fewest bits. Carefully select the smaller and cast it to the type of
607 * the larger - this cannot overflow. Do not cast in the following test
608 * - it will break on either 16 or 64 bit platforms.
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->save_buffer_ptr, save_size);
617
618 png_ptr->skip_length -= skip_length;
619 png_ptr->buffer_size -= save_size;
620 png_ptr->save_buffer_size -= save_size;
621 png_ptr->save_buffer_ptr += save_size;
622 }
623 if (png_ptr->skip_length && png_ptr->current_buffer_size)
624 {
625 png_size_t save_size = png_ptr->current_buffer_size;
626 png_uint_32 skip_length = png_ptr->skip_length;
627
628 /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
629 * the same problem exists as above and the same solution.
630 */
631 if (skip_length < save_size)
632 save_size = (png_size_t)skip_length;
633
634 else
635 skip_length = (png_uint_32)save_size;
636
637 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
638
639 png_ptr->skip_length -= skip_length;
640 png_ptr->buffer_size -= save_size;
641 png_ptr->current_buffer_size -= save_size;
642 png_ptr->current_buffer_ptr += save_size;
643 }
644 if (!png_ptr->skip_length)
645 {
646 if (png_ptr->buffer_size < 4)
647 {
648 png_push_save_buffer(png_ptr);
649 return;
650 }
651
652 png_crc_finish(png_ptr, 0);
653 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
654 }
655}
656
657void PNGCBAPI
658png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
659{
660 png_bytep ptr;
661
662 if (png_ptr == NULL)
663 return;
664
665 ptr = buffer;
666 if (png_ptr->save_buffer_size)
667 {
668 png_size_t save_size;
669
670 if (length < png_ptr->save_buffer_size)
671 save_size = length;
672
673 else
674 save_size = png_ptr->save_buffer_size;
675
676 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
677 length -= save_size;
678 ptr += save_size;
679 png_ptr->buffer_size -= save_size;
680 png_ptr->save_buffer_size -= save_size;
681 png_ptr->save_buffer_ptr += save_size;
682 }
683 if (length && png_ptr->current_buffer_size)
684 {
685 png_size_t save_size;
686
687 if (length < png_ptr->current_buffer_size)
688 save_size = length;
689
690 else
691 save_size = png_ptr->current_buffer_size;
692
693 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
694 png_ptr->buffer_size -= save_size;
695 png_ptr->current_buffer_size -= save_size;
696 png_ptr->current_buffer_ptr += save_size;
697 }
698}
699
700void /* PRIVATE */
701png_push_save_buffer(png_structp png_ptr)
702{
703 if (png_ptr->save_buffer_size)
704 {
705 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
706 {
707 png_size_t i, istop;
708 png_bytep sp;
709 png_bytep dp;
710
711 istop = png_ptr->save_buffer_size;
712 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
713 i < istop; i++, sp++, dp++)
714 {
715 *dp = *sp;
716 }
717 }
718 }
719 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
720 png_ptr->save_buffer_max)
721 {
722 png_size_t new_max;
723 png_bytep old_buffer;
724
725 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
726 (png_ptr->current_buffer_size + 256))
727 {
728 png_error(png_ptr, "Potential overflow of save_buffer");
729 }
730
731 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
732 old_buffer = png_ptr->save_buffer;
733 png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max);
734
735 if (png_ptr->save_buffer == NULL)
736 {
737 png_free(png_ptr, old_buffer);
738 png_error(png_ptr, "Insufficient memory for save_buffer");
739 }
740
741 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
742 png_free(png_ptr, old_buffer);
743 png_ptr->save_buffer_max = new_max;
744 }
745 if (png_ptr->current_buffer_size)
746 {
747 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
748 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
749 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
750 png_ptr->current_buffer_size = 0;
751 }
752 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
753 png_ptr->buffer_size = 0;
754}
755
756void /* PRIVATE */
757png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
758 png_size_t buffer_length)
759{
760 png_ptr->current_buffer = buffer;
761 png_ptr->current_buffer_size = buffer_length;
762 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
763 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
764}
765
766void /* PRIVATE */
767png_push_read_IDAT(png_structp png_ptr)
768{
769 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
770 {
771 png_byte chunk_length[4];
772 png_byte chunk_tag[4];
773
774 /* TODO: this code can be commoned up with the same code in push_read */
775 if (png_ptr->buffer_size < 8)
776 {
777 png_push_save_buffer(png_ptr);
778 return;
779 }
780
781 png_push_fill_buffer(png_ptr, chunk_length, 4);
782 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
783 png_reset_crc(png_ptr);
784 png_crc_read(png_ptr, chunk_tag, 4);
785 png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
786 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
787
788 if (png_ptr->chunk_name != png_IDAT)
789 {
790 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
791
792 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
793 png_error(png_ptr, "Not enough compressed data");
794
795 return;
796 }
797
798 png_ptr->idat_size = png_ptr->push_length;
799 }
800
801 if (png_ptr->idat_size && png_ptr->save_buffer_size)
802 {
803 png_size_t save_size = png_ptr->save_buffer_size;
804 png_uint_32 idat_size = png_ptr->idat_size;
805
806 /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
807 * are of different types and we don't know which variable has the fewest
808 * bits. Carefully select the smaller and cast it to the type of the
809 * larger - this cannot overflow. Do not cast in the following test - it
810 * will break on either 16 or 64 bit platforms.
811 */
812 if (idat_size < save_size)
813 save_size = (png_size_t)idat_size;
814
815 else
816 idat_size = (png_uint_32)save_size;
817
818 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
819
820 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
821
822 png_ptr->idat_size -= idat_size;
823 png_ptr->buffer_size -= save_size;
824 png_ptr->save_buffer_size -= save_size;
825 png_ptr->save_buffer_ptr += save_size;
826 }
827
828 if (png_ptr->idat_size && png_ptr->current_buffer_size)
829 {
830 png_size_t save_size = png_ptr->current_buffer_size;
831 png_uint_32 idat_size = png_ptr->idat_size;
832
833 /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
834 * are of different types and we don't know which variable has the fewest
835 * bits. Carefully select the smaller and cast it to the type of the
836 * larger - this cannot overflow.
837 */
838 if (idat_size < save_size)
839 save_size = (png_size_t)idat_size;
840
841 else
842 idat_size = (png_uint_32)save_size;
843
844 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
845
846 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
847
848 png_ptr->idat_size -= idat_size;
849 png_ptr->buffer_size -= save_size;
850 png_ptr->current_buffer_size -= save_size;
851 png_ptr->current_buffer_ptr += save_size;
852 }
853 if (!png_ptr->idat_size)
854 {
855 if (png_ptr->buffer_size < 4)
856 {
857 png_push_save_buffer(png_ptr);
858 return;
859 }
860
861 png_crc_finish(png_ptr, 0);
862 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
863 png_ptr->mode |= PNG_AFTER_IDAT;
864 }
865}
866
867void /* PRIVATE */
868png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
869 png_size_t buffer_length)
870{
871 /* The caller checks for a non-zero buffer length. */
872 if (!(buffer_length > 0) || buffer == NULL)
873 png_error(png_ptr, "No IDAT data (internal error)");
874
875 /* This routine must process all the data it has been given
876 * before returning, calling the row callback as required to
877 * handle the uncompressed results.
878 */
879 png_ptr->zstream.next_in = buffer;
880 png_ptr->zstream.avail_in = (uInt)buffer_length;
881
882 /* Keep going until the decompressed data is all processed
883 * or the stream marked as finished.
884 */
885 while (png_ptr->zstream.avail_in > 0 &&
886 !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
887 {
888 int ret;
889
890 /* We have data for zlib, but we must check that zlib
891 * has someplace to put the results. It doesn't matter
892 * if we don't expect any results -- it may be the input
893 * data is just the LZ end code.
894 */
895 if (!(png_ptr->zstream.avail_out > 0))
896 {
897 png_ptr->zstream.avail_out =
898 (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
899 png_ptr->iwidth) + 1;
900
901 png_ptr->zstream.next_out = png_ptr->row_buf;
902 }
903
904 /* Using Z_SYNC_FLUSH here means that an unterminated
905 * LZ stream (a stream with a missing end code) can still
906 * be handled, otherwise (Z_NO_FLUSH) a future zlib
907 * implementation might defer output and therefore
908 * change the current behavior (see comments in inflate.c
909 * for why this doesn't happen at present with zlib 1.2.5).
910 */
911 ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
912
913 /* Check for any failure before proceeding. */
914 if (ret != Z_OK && ret != Z_STREAM_END)
915 {
916 /* Terminate the decompression. */
917 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
918
919 /* This may be a truncated stream (missing or
920 * damaged end code). Treat that as a warning.
921 */
922 if (png_ptr->row_number >= png_ptr->num_rows ||
923 png_ptr->pass > 6)
924 png_warning(png_ptr, "Truncated compressed data in IDAT");
925
926 else
927 png_error(png_ptr, "Decompression error in IDAT");
928
929 /* Skip the check on unprocessed input */
930 return;
931 }
932
933 /* Did inflate output any data? */
934 if (png_ptr->zstream.next_out != png_ptr->row_buf)
935 {
936 /* Is this unexpected data after the last row?
937 * If it is, artificially terminate the LZ output
938 * here.
939 */
940 if (png_ptr->row_number >= png_ptr->num_rows ||
941 png_ptr->pass > 6)
942 {
943 /* Extra data. */
944 png_warning(png_ptr, "Extra compressed data in IDAT");
945 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
946
947 /* Do no more processing; skip the unprocessed
948 * input check below.
949 */
950 return;
951 }
952
953 /* Do we have a complete row? */
954 if (png_ptr->zstream.avail_out == 0)
955 png_push_process_row(png_ptr);
956 }
957
958 /* And check for the end of the stream. */
959 if (ret == Z_STREAM_END)
960 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
961 }
962
963 /* All the data should have been processed, if anything
964 * is left at this point we have bytes of IDAT data
965 * after the zlib end code.
966 */
967 if (png_ptr->zstream.avail_in > 0)
968 png_warning(png_ptr, "Extra compression data in IDAT");
969}
970
971void /* PRIVATE */
972png_push_process_row(png_structp png_ptr)
973{
974 /* 1.5.6: row_info moved out of png_struct to a local here. */
975 png_row_info row_info;
976
977 row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
978 row_info.color_type = png_ptr->color_type;
979 row_info.bit_depth = png_ptr->bit_depth;
980 row_info.channels = png_ptr->channels;
981 row_info.pixel_depth = png_ptr->pixel_depth;
982 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
983
984 if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
985 {
986 if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
987 png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
988 png_ptr->prev_row + 1, png_ptr->row_buf[0]);
989 else
990 png_error(png_ptr, "bad adaptive filter value");
991 }
992
993 /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
994 * 1.5.6, while the buffer really is this big in current versions of libpng
995 * it may not be in the future, so this was changed just to copy the
996 * interlaced row count:
997 */
998 png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
999
1000#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1001 if (png_ptr->transformations)
1002 png_do_read_transformations(png_ptr, &row_info);
1003#endif
1004
1005 /* The transformed pixel depth should match the depth now in row_info. */
1006 if (png_ptr->transformed_pixel_depth == 0)
1007 {
1008 png_ptr->transformed_pixel_depth = row_info.pixel_depth;
1009 if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
1010 png_error(png_ptr, "progressive row overflow");
1011 }
1012
1013 else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
1014 png_error(png_ptr, "internal progressive row size calculation error");
1015
1016
1017#ifdef PNG_READ_INTERLACING_SUPPORTED
1018 /* Blow up interlaced rows to full size */
1019 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
1020 {
1021 if (png_ptr->pass < 6)
1022 png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
1023 png_ptr->transformations);
1024
1025 switch (png_ptr->pass)
1026 {
1027 case 0:
1028 {
1029 int i;
1030 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
1031 {
1032 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1033 png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
1034 }
1035
1036 if (png_ptr->pass == 2) /* Pass 1 might be empty */
1037 {
1038 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1039 {
1040 png_push_have_row(png_ptr, NULL);
1041 png_read_push_finish_row(png_ptr);
1042 }
1043 }
1044
1045 if (png_ptr->pass == 4 && png_ptr->height <= 4)
1046 {
1047 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1048 {
1049 png_push_have_row(png_ptr, NULL);
1050 png_read_push_finish_row(png_ptr);
1051 }
1052 }
1053
1054 if (png_ptr->pass == 6 && png_ptr->height <= 4)
1055 {
1056 png_push_have_row(png_ptr, NULL);
1057 png_read_push_finish_row(png_ptr);
1058 }
1059
1060 break;
1061 }
1062
1063 case 1:
1064 {
1065 int i;
1066 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
1067 {
1068 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1069 png_read_push_finish_row(png_ptr);
1070 }
1071
1072 if (png_ptr->pass == 2) /* Skip top 4 generated rows */
1073 {
1074 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1075 {
1076 png_push_have_row(png_ptr, NULL);
1077 png_read_push_finish_row(png_ptr);
1078 }
1079 }
1080
1081 break;
1082 }
1083
1084 case 2:
1085 {
1086 int i;
1087
1088 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1089 {
1090 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1091 png_read_push_finish_row(png_ptr);
1092 }
1093
1094 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1095 {
1096 png_push_have_row(png_ptr, NULL);
1097 png_read_push_finish_row(png_ptr);
1098 }
1099
1100 if (png_ptr->pass == 4) /* Pass 3 might be empty */
1101 {
1102 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1103 {
1104 png_push_have_row(png_ptr, NULL);
1105 png_read_push_finish_row(png_ptr);
1106 }
1107 }
1108
1109 break;
1110 }
1111
1112 case 3:
1113 {
1114 int i;
1115
1116 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
1117 {
1118 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1119 png_read_push_finish_row(png_ptr);
1120 }
1121
1122 if (png_ptr->pass == 4) /* Skip top two generated rows */
1123 {
1124 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1125 {
1126 png_push_have_row(png_ptr, NULL);
1127 png_read_push_finish_row(png_ptr);
1128 }
1129 }
1130
1131 break;
1132 }
1133
1134 case 4:
1135 {
1136 int i;
1137
1138 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1139 {
1140 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1141 png_read_push_finish_row(png_ptr);
1142 }
1143
1144 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1145 {
1146 png_push_have_row(png_ptr, NULL);
1147 png_read_push_finish_row(png_ptr);
1148 }
1149
1150 if (png_ptr->pass == 6) /* Pass 5 might be empty */
1151 {
1152 png_push_have_row(png_ptr, NULL);
1153 png_read_push_finish_row(png_ptr);
1154 }
1155
1156 break;
1157 }
1158
1159 case 5:
1160 {
1161 int i;
1162
1163 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1164 {
1165 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1166 png_read_push_finish_row(png_ptr);
1167 }
1168
1169 if (png_ptr->pass == 6) /* Skip top generated row */
1170 {
1171 png_push_have_row(png_ptr, NULL);
1172 png_read_push_finish_row(png_ptr);
1173 }
1174
1175 break;
1176 }
1177
1178 default:
1179 case 6:
1180 {
1181 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1182 png_read_push_finish_row(png_ptr);
1183
1184 if (png_ptr->pass != 6)
1185 break;
1186
1187 png_push_have_row(png_ptr, NULL);
1188 png_read_push_finish_row(png_ptr);
1189 }
1190 }
1191 }
1192 else
1193#endif
1194 {
1195 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1196 png_read_push_finish_row(png_ptr);
1197 }
1198}
1199
1200void /* PRIVATE */
1201png_read_push_finish_row(png_structp png_ptr)
1202{
1203#ifdef PNG_READ_INTERLACING_SUPPORTED
1204 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1205
1206 /* Start of interlace block */
1207 static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1208
1209 /* Offset to next interlace block */
1210 static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1211
1212 /* Start of interlace block in the y direction */
1213 static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1214
1215 /* Offset to next interlace block in the y direction */
1216 static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1217
1218 /* Height of interlace block. This is not currently used - if you need
1219 * it, uncomment it here and in png.h
1220 static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1221 */
1222#endif
1223
1224 png_ptr->row_number++;
1225 if (png_ptr->row_number < png_ptr->num_rows)
1226 return;
1227
1228#ifdef PNG_READ_INTERLACING_SUPPORTED
1229 if (png_ptr->interlaced)
1230 {
1231 png_ptr->row_number = 0;
1232 png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
1233
1234 do
1235 {
1236 png_ptr->pass++;
1237 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1238 (png_ptr->pass == 3 && png_ptr->width < 3) ||
1239 (png_ptr->pass == 5 && png_ptr->width < 2))
1240 png_ptr->pass++;
1241
1242 if (png_ptr->pass > 7)
1243 png_ptr->pass--;
1244
1245 if (png_ptr->pass >= 7)
1246 break;
1247
1248 png_ptr->iwidth = (png_ptr->width +
1249 png_pass_inc[png_ptr->pass] - 1 -
1250 png_pass_start[png_ptr->pass]) /
1251 png_pass_inc[png_ptr->pass];
1252
1253 if (png_ptr->transformations & PNG_INTERLACE)
1254 break;
1255
1256 png_ptr->num_rows = (png_ptr->height +
1257 png_pass_yinc[png_ptr->pass] - 1 -
1258 png_pass_ystart[png_ptr->pass]) /
1259 png_pass_yinc[png_ptr->pass];
1260
1261 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1262 }
1263#endif /* PNG_READ_INTERLACING_SUPPORTED */
1264}
1265
1266#ifdef PNG_READ_tEXt_SUPPORTED
1267void /* PRIVATE */
1268png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1269 length)
1270{
1271 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1272 {
1273 PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
1274 png_error(png_ptr, "Out of place tEXt");
1275 /* NOT REACHED */
1276 }
1277
1278#ifdef PNG_MAX_MALLOC_64K
1279 png_ptr->skip_length = 0; /* This may not be necessary */
1280
1281 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1282 {
1283 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1284 png_ptr->skip_length = length - (png_uint_32)65535L;
1285 length = (png_uint_32)65535L;
1286 }
1287#endif
1288
1289 png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
1290 png_ptr->current_text[length] = '\0';
1291 png_ptr->current_text_ptr = png_ptr->current_text;
1292 png_ptr->current_text_size = (png_size_t)length;
1293 png_ptr->current_text_left = (png_size_t)length;
1294 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1295}
1296
1297void /* PRIVATE */
1298png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1299{
1300 if (png_ptr->buffer_size && png_ptr->current_text_left)
1301 {
1302 png_size_t text_size;
1303
1304 if (png_ptr->buffer_size < png_ptr->current_text_left)
1305 text_size = png_ptr->buffer_size;
1306
1307 else
1308 text_size = png_ptr->current_text_left;
1309
1310 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1311 png_ptr->current_text_left -= text_size;
1312 png_ptr->current_text_ptr += text_size;
1313 }
1314 if (!(png_ptr->current_text_left))
1315 {
1316 png_textp text_ptr;
1317 png_charp text;
1318 png_charp key;
1319 int ret;
1320
1321 if (png_ptr->buffer_size < 4)
1322 {
1323 png_push_save_buffer(png_ptr);
1324 return;
1325 }
1326
1327 png_push_crc_finish(png_ptr);
1328
1329#ifdef PNG_MAX_MALLOC_64K
1330 if (png_ptr->skip_length)
1331 return;
1332#endif
1333
1334 key = png_ptr->current_text;
1335
1336 for (text = key; *text; text++)
1337 /* Empty loop */ ;
1338
1339 if (text < key + png_ptr->current_text_size)
1340 text++;
1341
1342 text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text));
1343 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1344 text_ptr->key = key;
1345 text_ptr->itxt_length = 0;
1346 text_ptr->lang = NULL;
1347 text_ptr->lang_key = NULL;
1348 text_ptr->text = text;
1349
1350 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1351
1352 png_free(png_ptr, key);
1353 png_free(png_ptr, text_ptr);
1354 png_ptr->current_text = NULL;
1355
1356 if (ret)
1357 png_warning(png_ptr, "Insufficient memory to store text chunk");
1358 }
1359}
1360#endif
1361
1362#ifdef PNG_READ_zTXt_SUPPORTED
1363void /* PRIVATE */
1364png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1365 length)
1366{
1367 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1368 {
1369 PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
1370 png_error(png_ptr, "Out of place zTXt");
1371 /* NOT REACHED */
1372 }
1373
1374#ifdef PNG_MAX_MALLOC_64K
1375 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1376 * to be able to store the uncompressed data. Actually, the threshold
1377 * is probably around 32K, but it isn't as definite as 64K is.
1378 */
1379 if (length > (png_uint_32)65535L)
1380 {
1381 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1382 png_push_crc_skip(png_ptr, length);
1383 return;
1384 }
1385#endif
1386
1387 png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
1388 png_ptr->current_text[length] = '\0';
1389 png_ptr->current_text_ptr = png_ptr->current_text;
1390 png_ptr->current_text_size = (png_size_t)length;
1391 png_ptr->current_text_left = (png_size_t)length;
1392 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1393}
1394
1395void /* PRIVATE */
1396png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1397{
1398 if (png_ptr->buffer_size && png_ptr->current_text_left)
1399 {
1400 png_size_t text_size;
1401
1402 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1403 text_size = png_ptr->buffer_size;
1404
1405 else
1406 text_size = png_ptr->current_text_left;
1407
1408 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1409 png_ptr->current_text_left -= text_size;
1410 png_ptr->current_text_ptr += text_size;
1411 }
1412 if (!(png_ptr->current_text_left))
1413 {
1414 png_textp text_ptr;
1415 png_charp text;
1416 png_charp key;
1417 int ret;
1418 png_size_t text_size, key_size;
1419
1420 if (png_ptr->buffer_size < 4)
1421 {
1422 png_push_save_buffer(png_ptr);
1423 return;
1424 }
1425
1426 png_push_crc_finish(png_ptr);
1427
1428 key = png_ptr->current_text;
1429
1430 for (text = key; *text; text++)
1431 /* Empty loop */ ;
1432
1433 /* zTXt can't have zero text */
1434 if (text >= key + png_ptr->current_text_size)
1435 {
1436 png_ptr->current_text = NULL;
1437 png_free(png_ptr, key);
1438 return;
1439 }
1440
1441 text++;
1442
1443 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1444 {
1445 png_ptr->current_text = NULL;
1446 png_free(png_ptr, key);
1447 return;
1448 }
1449
1450 text++;
1451
1452 png_ptr->zstream.next_in = (png_bytep)text;
1453 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1454 (text - key));
1455 png_ptr->zstream.next_out = png_ptr->zbuf;
1456 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1457
1458 key_size = text - key;
1459 text_size = 0;
1460 text = NULL;
1461 ret = Z_STREAM_END;
1462
1463 while (png_ptr->zstream.avail_in)
1464 {
1465 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1466 if (ret != Z_OK && ret != Z_STREAM_END)
1467 {
1468 inflateReset(&png_ptr->zstream);
1469 png_ptr->zstream.avail_in = 0;
1470 png_ptr->current_text = NULL;
1471 png_free(png_ptr, key);
1472 png_free(png_ptr, text);
1473 return;
1474 }
1475
1476 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1477 {
1478 if (text == NULL)
1479 {
1480 text = (png_charp)png_malloc(png_ptr,
1481 (png_ptr->zbuf_size
1482 - png_ptr->zstream.avail_out + key_size + 1));
1483
1484 png_memcpy(text + key_size, png_ptr->zbuf,
1485 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1486
1487 png_memcpy(text, key, key_size);
1488
1489 text_size = key_size + png_ptr->zbuf_size -
1490 png_ptr->zstream.avail_out;
1491
1492 *(text + text_size) = '\0';
1493 }
1494
1495 else
1496 {
1497 png_charp tmp;
1498
1499 tmp = text;
1500 text = (png_charp)png_malloc(png_ptr, text_size +
1501 (png_ptr->zbuf_size
1502 - png_ptr->zstream.avail_out + 1));
1503
1504 png_memcpy(text, tmp, text_size);
1505 png_free(png_ptr, tmp);
1506
1507 png_memcpy(text + text_size, png_ptr->zbuf,
1508 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1509
1510 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1511 *(text + text_size) = '\0';
1512 }
1513
1514 if (ret != Z_STREAM_END)
1515 {
1516 png_ptr->zstream.next_out = png_ptr->zbuf;
1517 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1518 }
1519 }
1520 else
1521 {
1522 break;
1523 }
1524
1525 if (ret == Z_STREAM_END)
1526 break;
1527 }
1528
1529 inflateReset(&png_ptr->zstream);
1530 png_ptr->zstream.avail_in = 0;
1531
1532 if (ret != Z_STREAM_END)
1533 {
1534 png_ptr->current_text = NULL;
1535 png_free(png_ptr, key);
1536 png_free(png_ptr, text);
1537 return;
1538 }
1539
1540 png_ptr->current_text = NULL;
1541 png_free(png_ptr, key);
1542 key = text;
1543 text += key_size;
1544
1545 text_ptr = (png_textp)png_malloc(png_ptr,
1546 png_sizeof(png_text));
1547 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1548 text_ptr->key = key;
1549 text_ptr->itxt_length = 0;
1550 text_ptr->lang = NULL;
1551 text_ptr->lang_key = NULL;
1552 text_ptr->text = text;
1553
1554 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1555
1556 png_free(png_ptr, key);
1557 png_free(png_ptr, text_ptr);
1558
1559 if (ret)
1560 png_warning(png_ptr, "Insufficient memory to store text chunk");
1561 }
1562}
1563#endif
1564
1565#ifdef PNG_READ_iTXt_SUPPORTED
1566void /* PRIVATE */
1567png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1568 length)
1569{
1570 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1571 {
1572 PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
1573 png_error(png_ptr, "Out of place iTXt");
1574 /* NOT REACHED */
1575 }
1576
1577#ifdef PNG_MAX_MALLOC_64K
1578 png_ptr->skip_length = 0; /* This may not be necessary */
1579
1580 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1581 {
1582 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1583 png_ptr->skip_length = length - (png_uint_32)65535L;
1584 length = (png_uint_32)65535L;
1585 }
1586#endif
1587
1588 png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
1589 png_ptr->current_text[length] = '\0';
1590 png_ptr->current_text_ptr = png_ptr->current_text;
1591 png_ptr->current_text_size = (png_size_t)length;
1592 png_ptr->current_text_left = (png_size_t)length;
1593 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1594}
1595
1596void /* PRIVATE */
1597png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1598{
1599
1600 if (png_ptr->buffer_size && png_ptr->current_text_left)
1601 {
1602 png_size_t text_size;
1603
1604 if (png_ptr->buffer_size < png_ptr->current_text_left)
1605 text_size = png_ptr->buffer_size;
1606
1607 else
1608 text_size = png_ptr->current_text_left;
1609
1610 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1611 png_ptr->current_text_left -= text_size;
1612 png_ptr->current_text_ptr += text_size;
1613 }
1614
1615 if (!(png_ptr->current_text_left))
1616 {
1617 png_textp text_ptr;
1618 png_charp key;
1619 int comp_flag;
1620 png_charp lang;
1621 png_charp lang_key;
1622 png_charp text;
1623 int ret;
1624
1625 if (png_ptr->buffer_size < 4)
1626 {
1627 png_push_save_buffer(png_ptr);
1628 return;
1629 }
1630
1631 png_push_crc_finish(png_ptr);
1632
1633#ifdef PNG_MAX_MALLOC_64K
1634 if (png_ptr->skip_length)
1635 return;
1636#endif
1637
1638 key = png_ptr->current_text;
1639
1640 for (lang = key; *lang; lang++)
1641 /* Empty loop */ ;
1642
1643 if (lang < key + png_ptr->current_text_size - 3)
1644 lang++;
1645
1646 comp_flag = *lang++;
1647 lang++; /* Skip comp_type, always zero */
1648
1649 for (lang_key = lang; *lang_key; lang_key++)
1650 /* Empty loop */ ;
1651
1652 lang_key++; /* Skip NUL separator */
1653
1654 text=lang_key;
1655
1656 if (lang_key < key + png_ptr->current_text_size - 1)
1657 {
1658 for (; *text; text++)
1659 /* Empty loop */ ;
1660 }
1661
1662 if (text < key + png_ptr->current_text_size)
1663 text++;
1664
1665 text_ptr = (png_textp)png_malloc(png_ptr,
1666 png_sizeof(png_text));
1667
1668 text_ptr->compression = comp_flag + 2;
1669 text_ptr->key = key;
1670 text_ptr->lang = lang;
1671 text_ptr->lang_key = lang_key;
1672 text_ptr->text = text;
1673 text_ptr->text_length = 0;
1674 text_ptr->itxt_length = png_strlen(text);
1675
1676 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1677
1678 png_ptr->current_text = NULL;
1679
1680 png_free(png_ptr, text_ptr);
1681 if (ret)
1682 png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
1683 }
1684}
1685#endif
1686
1687/* This function is called when we haven't found a handler for this
1688 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1689 * name or a critical chunk), the chunk is (currently) silently ignored.
1690 */
1691void /* PRIVATE */
1692png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1693 length)
1694{
1695 png_uint_32 skip = 0;
1696 png_uint_32 chunk_name = png_ptr->chunk_name;
1697
1698 if (PNG_CHUNK_CRITICAL(chunk_name))
1699 {
1700#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1701 if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
1702 PNG_HANDLE_CHUNK_ALWAYS
1703#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1704 && png_ptr->read_user_chunk_fn == NULL
1705#endif
1706 )
1707#endif
1708 png_chunk_error(png_ptr, "unknown critical chunk");
1709
1710 PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
1711 }
1712
1713#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1714 /* TODO: the code below is apparently just using the
1715 * png_struct::unknown_chunk member as a temporarily variable, it should be
1716 * possible to eliminate both it and the temporary buffer.
1717 */
1718 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1719 {
1720#ifdef PNG_MAX_MALLOC_64K
1721 if (length > 65535)
1722 {
1723 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1724 skip = length - 65535;
1725 length = 65535;
1726 }
1727#endif
1728 /* This is just a record for the user; libpng doesn't use the character
1729 * form of the name.
1730 */
1731 PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
1732
1733 png_ptr->unknown_chunk.size = length;
1734
1735 if (length == 0)
1736 png_ptr->unknown_chunk.data = NULL;
1737
1738 else
1739 {
1740 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1741 png_ptr->unknown_chunk.size);
1742 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data,
1743 png_ptr->unknown_chunk.size);
1744 }
1745
1746#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1747 if (png_ptr->read_user_chunk_fn != NULL)
1748 {
1749 /* Callback to user unknown chunk handler */
1750 int ret;
1751 ret = (*(png_ptr->read_user_chunk_fn))
1752 (png_ptr, &png_ptr->unknown_chunk);
1753
1754 if (ret < 0)
1755 png_chunk_error(png_ptr, "error in user chunk");
1756
1757 if (ret == 0)
1758 {
1759 if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
1760 if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
1761 PNG_HANDLE_CHUNK_ALWAYS)
1762 png_chunk_error(png_ptr, "unknown critical chunk");
1763 png_set_unknown_chunks(png_ptr, info_ptr,
1764 &png_ptr->unknown_chunk, 1);
1765 }
1766 }
1767
1768 else
1769#endif
1770 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1771 png_free(png_ptr, png_ptr->unknown_chunk.data);
1772 png_ptr->unknown_chunk.data = NULL;
1773 }
1774
1775 else
1776#endif
1777 skip=length;
1778 png_push_crc_skip(png_ptr, skip);
1779}
1780
1781void /* PRIVATE */
1782png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1783{
1784 if (png_ptr->info_fn != NULL)
1785 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1786}
1787
1788void /* PRIVATE */
1789png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1790{
1791 if (png_ptr->end_fn != NULL)
1792 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1793}
1794
1795void /* PRIVATE */
1796png_push_have_row(png_structp png_ptr, png_bytep row)
1797{
1798 if (png_ptr->row_fn != NULL)
1799 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1800 (int)png_ptr->pass);
1801}
1802
1803#ifdef PNG_READ_INTERLACING_SUPPORTED
1804void PNGAPI
1805png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
1806 png_const_bytep new_row)
1807{
1808 if (png_ptr == NULL)
1809 return;
1810
1811 /* new_row is a flag here - if it is NULL then the app callback was called
1812 * from an empty row (see the calls to png_struct::row_fn below), otherwise
1813 * it must be png_ptr->row_buf+1
1814 */
1815 if (new_row != NULL)
1816 png_combine_row(png_ptr, old_row, 1/*display*/);
1817}
1818#endif /* PNG_READ_INTERLACING_SUPPORTED */
1819
1820void PNGAPI
1821png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1822 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1823 png_progressive_end_ptr end_fn)
1824{
1825 if (png_ptr == NULL)
1826 return;
1827
1828 png_ptr->info_fn = info_fn;
1829 png_ptr->row_fn = row_fn;
1830 png_ptr->end_fn = end_fn;
1831
1832 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1833}
1834
1835png_voidp PNGAPI
1836png_get_progressive_ptr(png_const_structp png_ptr)
1837{
1838 if (png_ptr == NULL)
1839 return (NULL);
1840
1841 return png_ptr->io_ptr;
1842}
1843#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
generated by cgit v1.1 at 2024-11-03 22:24:51 +0000