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source: trunk/src/3rdparty/libpng/pngrutil.c@ 838

Last change on this file since 838 was 561, checked in by Dmitry A. Kuminov, 16 years ago
trunk: Merged in qt 4.6.1 sources.
File size: 93.1 KB

Line
1
2	/* pngrutil.c - utilities to read a PNG file
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	* This file contains routines that are only called from within
14	* libpng itself during the course of reading an image.
15	*/
16
17	#define PNG_INTERNAL
18	#include "png.h"
19	#if defined(PNG_READ_SUPPORTED)
20
21	#if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
22	# define WIN32_WCE_OLD
23	#endif
24
25	#ifdef PNG_FLOATING_POINT_SUPPORTED
26	# if defined(WIN32_WCE_OLD)
27	/* The strtod() function is not supported on WindowsCE */
28	__inline double png_strtod(png_structp png_ptr, PNG_CONST char nptr, char *endptr)
29	{
30	double result = 0;
31	int len;
32	wchar_t str, end;
33
34	len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
35	str = (wchar_t )png_malloc(png_ptr, len png_sizeof(wchar_t));
36	if ( NULL != str )
37	{
38	MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
39	result = wcstod(str, &end);
40	len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
41	endptr = (char )nptr + (png_strlen(nptr) - len + 1);
42	png_free(png_ptr, str);
43	}
44	return result;
45	}
46	# else
47	# define png_strtod(p,a,b) strtod(a,b)
48	# endif
49	#endif
50
51	png_uint_32 PNGAPI
52	png_get_uint_31(png_structp png_ptr, png_bytep buf)
53	{
54	#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
55	png_uint_32 i = png_get_uint_32(buf);
56	#else
57	/* Avoid an extra function call by inlining the result. */
58	png_uint_32 i = ((png_uint_32)(*buf) << 24) +
59	((png_uint_32)(*(buf + 1)) << 16) +
60	((png_uint_32)(*(buf + 2)) << 8) +
61	(png_uint_32)(*(buf + 3));
62	#endif
63	if (i > PNG_UINT_31_MAX)
64	png_error(png_ptr, "PNG unsigned integer out of range.");
65	return (i);
66	}
67	#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
68	/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
69	png_uint_32 PNGAPI
70	png_get_uint_32(png_bytep buf)
71	{
72	png_uint_32 i = ((png_uint_32)(*buf) << 24) +
73	((png_uint_32)(*(buf + 1)) << 16) +
74	((png_uint_32)(*(buf + 2)) << 8) +
75	(png_uint_32)(*(buf + 3));
76
77	return (i);
78	}
79
80	/* Grab a signed 32-bit integer from a buffer in big-endian format. The
81	* data is stored in the PNG file in two's complement format, and it is
82	* assumed that the machine format for signed integers is the same.
83	*/
84	png_int_32 PNGAPI
85	png_get_int_32(png_bytep buf)
86	{
87	png_int_32 i = ((png_int_32)(*buf) << 24) +
88	((png_int_32)(*(buf + 1)) << 16) +
89	((png_int_32)(*(buf + 2)) << 8) +
90	(png_int_32)(*(buf + 3));
91
92	return (i);
93	}
94
95	/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
96	png_uint_16 PNGAPI
97	png_get_uint_16(png_bytep buf)
98	{
99	png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
100	(png_uint_16)(*(buf + 1)));
101
102	return (i);
103	}
104	#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
105
106	/* Read the chunk header (length + type name).
107	* Put the type name into png_ptr->chunk_name, and return the length.
108	*/
109	png_uint_32 /* PRIVATE */
110	png_read_chunk_header(png_structp png_ptr)
111	{
112	png_byte buf[8];
113	png_uint_32 length;
114
115	/* Read the length and the chunk name */
116	png_read_data(png_ptr, buf, 8);
117	length = png_get_uint_31(png_ptr, buf);
118
119	/* Put the chunk name into png_ptr->chunk_name */
120	png_memcpy(png_ptr->chunk_name, buf + 4, 4);
121
122	png_debug2(0, "Reading %s chunk, length = %lu",
123	png_ptr->chunk_name, length);
124
125	/* Reset the crc and run it over the chunk name */
126	png_reset_crc(png_ptr);
127	png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
128
129	/* Check to see if chunk name is valid */
130	png_check_chunk_name(png_ptr, png_ptr->chunk_name);
131
132	return length;
133	}
134
135	/* Read data, and (optionally) run it through the CRC. */
136	void /* PRIVATE */
137	png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
138	{
139	if (png_ptr == NULL)
140	return;
141	png_read_data(png_ptr, buf, length);
142	png_calculate_crc(png_ptr, buf, length);
143	}
144
145	/* Optionally skip data and then check the CRC. Depending on whether we
146	* are reading a ancillary or critical chunk, and how the program has set
147	* things up, we may calculate the CRC on the data and print a message.
148	* Returns '1' if there was a CRC error, '0' otherwise.
149	*/
150	int /* PRIVATE */
151	png_crc_finish(png_structp png_ptr, png_uint_32 skip)
152	{
153	png_size_t i;
154	png_size_t istop = png_ptr->zbuf_size;
155
156	for (i = (png_size_t)skip; i > istop; i -= istop)
157	{
158	png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
159	}
160	if (i)
161	{
162	png_crc_read(png_ptr, png_ptr->zbuf, i);
163	}
164
165	if (png_crc_error(png_ptr))
166	{
167	if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
168	!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) \|\|
169	(!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
170	(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
171	{
172	png_chunk_warning(png_ptr, "CRC error");
173	}
174	else
175	{
176	png_chunk_error(png_ptr, "CRC error");
177	}
178	return (1);
179	}
180
181	return (0);
182	}
183
184	/* Compare the CRC stored in the PNG file with that calculated by libpng from
185	* the data it has read thus far.
186	*/
187	int /* PRIVATE */
188	png_crc_error(png_structp png_ptr)
189	{
190	png_byte crc_bytes[4];
191	png_uint_32 crc;
192	int need_crc = 1;
193
194	if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
195	{
196	if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
197	(PNG_FLAG_CRC_ANCILLARY_USE \| PNG_FLAG_CRC_ANCILLARY_NOWARN))
198	need_crc = 0;
199	}
200	else /* critical */
201	{
202	if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
203	need_crc = 0;
204	}
205
206	png_read_data(png_ptr, crc_bytes, 4);
207
208	if (need_crc)
209	{
210	crc = png_get_uint_32(crc_bytes);
211	return ((int)(crc != png_ptr->crc));
212	}
213	else
214	return (0);
215	}
216
217	#if defined(PNG_READ_zTXt_SUPPORTED) \|\| defined(PNG_READ_iTXt_SUPPORTED) \|\| \
218	defined(PNG_READ_iCCP_SUPPORTED)
219	/*
220	* Decompress trailing data in a chunk. The assumption is that chunkdata
221	* points at an allocated area holding the contents of a chunk with a
222	* trailing compressed part. What we get back is an allocated area
223	* holding the original prefix part and an uncompressed version of the
224	* trailing part (the malloc area passed in is freed).
225	*/
226	void /* PRIVATE */
227	png_decompress_chunk(png_structp png_ptr, int comp_type,
228	png_size_t chunklength,
229	png_size_t prefix_size, png_size_t *newlength)
230	{
231	static PNG_CONST char msg[] = "Error decoding compressed text";
232	png_charp text;
233	png_size_t text_size;
234
235	if (comp_type == PNG_COMPRESSION_TYPE_BASE)
236	{
237	int ret = Z_OK;
238	png_ptr->zstream.next_in = (png_bytep)(png_ptr->chunkdata + prefix_size);
239	png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
240	png_ptr->zstream.next_out = png_ptr->zbuf;
241	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
242
243	text_size = 0;
244	text = NULL;
245
246	while (png_ptr->zstream.avail_in)
247	{
248	ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
249	if (ret != Z_OK && ret != Z_STREAM_END)
250	{
251	if (png_ptr->zstream.msg != NULL)
252	png_warning(png_ptr, png_ptr->zstream.msg);
253	else
254	png_warning(png_ptr, msg);
255	inflateReset(&png_ptr->zstream);
256	png_ptr->zstream.avail_in = 0;
257
258	if (text == NULL)
259	{
260	text_size = prefix_size + png_sizeof(msg) + 1;
261	text = (png_charp)png_malloc_warn(png_ptr, text_size);
262	if (text == NULL)
263	{
264	png_free(png_ptr, png_ptr->chunkdata);
265	png_ptr->chunkdata = NULL;
266	png_error(png_ptr, "Not enough memory to decompress chunk");
267	}
268	png_memcpy(text, png_ptr->chunkdata, prefix_size);
269	}
270
271	text[text_size - 1] = 0x00;
272
273	/* Copy what we can of the error message into the text chunk */
274	text_size = (png_size_t)(chunklength -
275	(text - png_ptr->chunkdata) - 1);
276	if (text_size > png_sizeof(msg))
277	text_size = png_sizeof(msg);
278	png_memcpy(text + prefix_size, msg, text_size);
279	break;
280	}
281	if (!png_ptr->zstream.avail_out \|\| ret == Z_STREAM_END)
282	{
283	if (text == NULL)
284	{
285	text_size = prefix_size +
286	png_ptr->zbuf_size - png_ptr->zstream.avail_out;
287	text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
288	if (text == NULL)
289	{
290	png_free(png_ptr, png_ptr->chunkdata);
291	png_ptr->chunkdata = NULL;
292	png_error(png_ptr,
293	"Not enough memory to decompress chunk.");
294	}
295	png_memcpy(text + prefix_size, png_ptr->zbuf,
296	text_size - prefix_size);
297	png_memcpy(text, png_ptr->chunkdata, prefix_size);
298	*(text + text_size) = 0x00;
299	}
300	else
301	{
302	png_charp tmp;
303
304	tmp = text;
305	text = (png_charp)png_malloc_warn(png_ptr,
306	(png_uint_32)(text_size +
307	png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
308	if (text == NULL)
309	{
310	png_free(png_ptr, tmp);
311	png_free(png_ptr, png_ptr->chunkdata);
312	png_ptr->chunkdata = NULL;
313	png_error(png_ptr,
314	"Not enough memory to decompress chunk..");
315	}
316	png_memcpy(text, tmp, text_size);
317	png_free(png_ptr, tmp);
318	png_memcpy(text + text_size, png_ptr->zbuf,
319	(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
320	text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
321	*(text + text_size) = 0x00;
322	}
323	if (ret == Z_STREAM_END)
324	break;
325	else
326	{
327	png_ptr->zstream.next_out = png_ptr->zbuf;
328	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
329	}
330	}
331	}
332	if (ret != Z_STREAM_END)
333	{
334	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
335	char umsg[52];
336
337	if (ret == Z_BUF_ERROR)
338	png_snprintf(umsg, 52,
339	"Buffer error in compressed datastream in %s chunk",
340	png_ptr->chunk_name);
341
342	else if (ret == Z_DATA_ERROR)
343	png_snprintf(umsg, 52,
344	"Data error in compressed datastream in %s chunk",
345	png_ptr->chunk_name);
346
347	else
348	png_snprintf(umsg, 52,
349	"Incomplete compressed datastream in %s chunk",
350	png_ptr->chunk_name);
351
352	png_warning(png_ptr, umsg);
353	#else
354	png_warning(png_ptr,
355	"Incomplete compressed datastream in chunk other than IDAT");
356	#endif
357	text_size = prefix_size;
358	if (text == NULL)
359	{
360	text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
361	if (text == NULL)
362	{
363	png_free(png_ptr, png_ptr->chunkdata);
364	png_ptr->chunkdata = NULL;
365	png_error(png_ptr, "Not enough memory for text.");
366	}
367	png_memcpy(text, png_ptr->chunkdata, prefix_size);
368	}
369	*(text + text_size) = 0x00;
370	}
371
372	inflateReset(&png_ptr->zstream);
373	png_ptr->zstream.avail_in = 0;
374
375	png_free(png_ptr, png_ptr->chunkdata);
376	png_ptr->chunkdata = text;
377	*newlength=text_size;
378	}
379	else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
380	{
381	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
382	char umsg[50];
383
384	png_snprintf(umsg, 50, "Unknown zTXt compression type %d", comp_type);
385	png_warning(png_ptr, umsg);
386	#else
387	png_warning(png_ptr, "Unknown zTXt compression type");
388	#endif
389
390	*(png_ptr->chunkdata + prefix_size) = 0x00;
391	*newlength = prefix_size;
392	}
393	}
394	#endif
395
396	/* Read and check the IDHR chunk */
397	void /* PRIVATE */
398	png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
399	{
400	png_byte buf[13];
401	png_uint_32 width, height;
402	int bit_depth, color_type, compression_type, filter_type;
403	int interlace_type;
404
405	png_debug(1, "in png_handle_IHDR");
406
407	if (png_ptr->mode & PNG_HAVE_IHDR)
408	png_error(png_ptr, "Out of place IHDR");
409
410	/* Check the length */
411	if (length != 13)
412	png_error(png_ptr, "Invalid IHDR chunk");
413
414	png_ptr->mode \|= PNG_HAVE_IHDR;
415
416	png_crc_read(png_ptr, buf, 13);
417	png_crc_finish(png_ptr, 0);
418
419	width = png_get_uint_31(png_ptr, buf);
420	height = png_get_uint_31(png_ptr, buf + 4);
421	bit_depth = buf[8];
422	color_type = buf[9];
423	compression_type = buf[10];
424	filter_type = buf[11];
425	interlace_type = buf[12];
426
427	/* Set internal variables */
428	png_ptr->width = width;
429	png_ptr->height = height;
430	png_ptr->bit_depth = (png_byte)bit_depth;
431	png_ptr->interlaced = (png_byte)interlace_type;
432	png_ptr->color_type = (png_byte)color_type;
433	#if defined(PNG_MNG_FEATURES_SUPPORTED)
434	png_ptr->filter_type = (png_byte)filter_type;
435	#endif
436	png_ptr->compression_type = (png_byte)compression_type;
437
438	/* Find number of channels */
439	switch (png_ptr->color_type)
440	{
441	case PNG_COLOR_TYPE_GRAY:
442	case PNG_COLOR_TYPE_PALETTE:
443	png_ptr->channels = 1;
444	break;
445
446	case PNG_COLOR_TYPE_RGB:
447	png_ptr->channels = 3;
448	break;
449
450	case PNG_COLOR_TYPE_GRAY_ALPHA:
451	png_ptr->channels = 2;
452	break;
453
454	case PNG_COLOR_TYPE_RGB_ALPHA:
455	png_ptr->channels = 4;
456	break;
457	}
458
459	/* Set up other useful info */
460	png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
461	png_ptr->channels);
462	png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
463	png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
464	png_debug1(3, "channels = %d", png_ptr->channels);
465	png_debug1(3, "rowbytes = %lu", png_ptr->rowbytes);
466	png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
467	color_type, interlace_type, compression_type, filter_type);
468	}
469
470	/* Read and check the palette */
471	void /* PRIVATE */
472	png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
473	{
474	png_color palette[PNG_MAX_PALETTE_LENGTH];
475	int num, i;
476	#ifndef PNG_NO_POINTER_INDEXING
477	png_colorp pal_ptr;
478	#endif
479
480	png_debug(1, "in png_handle_PLTE");
481
482	if (!(png_ptr->mode & PNG_HAVE_IHDR))
483	png_error(png_ptr, "Missing IHDR before PLTE");
484
485	else if (png_ptr->mode & PNG_HAVE_IDAT)
486	{
487	png_warning(png_ptr, "Invalid PLTE after IDAT");
488	png_crc_finish(png_ptr, length);
489	return;
490	}
491
492	else if (png_ptr->mode & PNG_HAVE_PLTE)
493	png_error(png_ptr, "Duplicate PLTE chunk");
494
495	png_ptr->mode \|= PNG_HAVE_PLTE;
496
497	if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
498	{
499	png_warning(png_ptr,
500	"Ignoring PLTE chunk in grayscale PNG");
501	png_crc_finish(png_ptr, length);
502	return;
503	}
504	#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
505	if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
506	{
507	png_crc_finish(png_ptr, length);
508	return;
509	}
510	#endif
511
512	if (length > 3*PNG_MAX_PALETTE_LENGTH \|\| length % 3)
513	{
514	if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
515	{
516	png_warning(png_ptr, "Invalid palette chunk");
517	png_crc_finish(png_ptr, length);
518	return;
519	}
520
521	else
522	{
523	png_error(png_ptr, "Invalid palette chunk");
524	}
525	}
526
527	num = (int)length / 3;
528
529	#ifndef PNG_NO_POINTER_INDEXING
530	for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
531	{
532	png_byte buf[3];
533
534	png_crc_read(png_ptr, buf, 3);
535	pal_ptr->red = buf[0];
536	pal_ptr->green = buf[1];
537	pal_ptr->blue = buf[2];
538	}
539	#else
540	for (i = 0; i < num; i++)
541	{
542	png_byte buf[3];
543
544	png_crc_read(png_ptr, buf, 3);
545	/* Don't depend upon png_color being any order */
546	palette[i].red = buf[0];
547	palette[i].green = buf[1];
548	palette[i].blue = buf[2];
549	}
550	#endif
551
552	/* If we actually NEED the PLTE chunk (ie for a paletted image), we do
553	* whatever the normal CRC configuration tells us. However, if we
554	* have an RGB image, the PLTE can be considered ancillary, so
555	* we will act as though it is.
556	*/
557	#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
558	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
559	#endif
560	{
561	png_crc_finish(png_ptr, 0);
562	}
563	#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
564	else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
565	{
566	/* If we don't want to use the data from an ancillary chunk,
567	we have two options: an error abort, or a warning and we
568	ignore the data in this chunk (which should be OK, since
569	it's considered ancillary for a RGB or RGBA image). */
570	if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
571	{
572	if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
573	{
574	png_chunk_error(png_ptr, "CRC error");
575	}
576	else
577	{
578	png_chunk_warning(png_ptr, "CRC error");
579	return;
580	}
581	}
582	/* Otherwise, we (optionally) emit a warning and use the chunk. */
583	else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
584	{
585	png_chunk_warning(png_ptr, "CRC error");
586	}
587	}
588	#endif
589
590	png_set_PLTE(png_ptr, info_ptr, palette, num);
591
592	#if defined(PNG_READ_tRNS_SUPPORTED)
593	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
594	{
595	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
596	{
597	if (png_ptr->num_trans > (png_uint_16)num)
598	{
599	png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
600	png_ptr->num_trans = (png_uint_16)num;
601	}
602	if (info_ptr->num_trans > (png_uint_16)num)
603	{
604	png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
605	info_ptr->num_trans = (png_uint_16)num;
606	}
607	}
608	}
609	#endif
610
611	}
612
613	void /* PRIVATE */
614	png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
615	{
616	png_debug(1, "in png_handle_IEND");
617
618	if (!(png_ptr->mode & PNG_HAVE_IHDR) \|\| !(png_ptr->mode & PNG_HAVE_IDAT))
619	{
620	png_error(png_ptr, "No image in file");
621	}
622
623	png_ptr->mode \|= (PNG_AFTER_IDAT \| PNG_HAVE_IEND);
624
625	if (length != 0)
626	{
627	png_warning(png_ptr, "Incorrect IEND chunk length");
628	}
629	png_crc_finish(png_ptr, length);
630
631	info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */
632	}
633
634	#if defined(PNG_READ_gAMA_SUPPORTED)
635	void /* PRIVATE */
636	png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
637	{
638	png_fixed_point igamma;
639	#ifdef PNG_FLOATING_POINT_SUPPORTED
640	float file_gamma;
641	#endif
642	png_byte buf[4];
643
644	png_debug(1, "in png_handle_gAMA");
645
646	if (!(png_ptr->mode & PNG_HAVE_IHDR))
647	png_error(png_ptr, "Missing IHDR before gAMA");
648	else if (png_ptr->mode & PNG_HAVE_IDAT)
649	{
650	png_warning(png_ptr, "Invalid gAMA after IDAT");
651	png_crc_finish(png_ptr, length);
652	return;
653	}
654	else if (png_ptr->mode & PNG_HAVE_PLTE)
655	/* Should be an error, but we can cope with it */
656	png_warning(png_ptr, "Out of place gAMA chunk");
657
658	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
659	#if defined(PNG_READ_sRGB_SUPPORTED)
660	&& !(info_ptr->valid & PNG_INFO_sRGB)
661	#endif
662	)
663	{
664	png_warning(png_ptr, "Duplicate gAMA chunk");
665	png_crc_finish(png_ptr, length);
666	return;
667	}
668
669	if (length != 4)
670	{
671	png_warning(png_ptr, "Incorrect gAMA chunk length");
672	png_crc_finish(png_ptr, length);
673	return;
674	}
675
676	png_crc_read(png_ptr, buf, 4);
677	if (png_crc_finish(png_ptr, 0))
678	return;
679
680	igamma = (png_fixed_point)png_get_uint_32(buf);
681	/* Check for zero gamma */
682	if (igamma == 0)
683	{
684	png_warning(png_ptr,
685	"Ignoring gAMA chunk with gamma=0");
686	return;
687	}
688
689	#if defined(PNG_READ_sRGB_SUPPORTED)
690	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
691	if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
692	{
693	png_warning(png_ptr,
694	"Ignoring incorrect gAMA value when sRGB is also present");
695	#ifndef PNG_NO_CONSOLE_IO
696	fprintf(stderr, "gamma = (%d/100000)", (int)igamma);
697	#endif
698	return;
699	}
700	#endif /* PNG_READ_sRGB_SUPPORTED */
701
702	#ifdef PNG_FLOATING_POINT_SUPPORTED
703	file_gamma = (float)igamma / (float)100000.0;
704	# ifdef PNG_READ_GAMMA_SUPPORTED
705	png_ptr->gamma = file_gamma;
706	# endif
707	png_set_gAMA(png_ptr, info_ptr, file_gamma);
708	#endif
709	#ifdef PNG_FIXED_POINT_SUPPORTED
710	png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
711	#endif
712	}
713	#endif
714
715	#if defined(PNG_READ_sBIT_SUPPORTED)
716	void /* PRIVATE */
717	png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
718	{
719	png_size_t truelen;
720	png_byte buf[4];
721
722	png_debug(1, "in png_handle_sBIT");
723
724	buf[0] = buf[1] = buf[2] = buf[3] = 0;
725
726	if (!(png_ptr->mode & PNG_HAVE_IHDR))
727	png_error(png_ptr, "Missing IHDR before sBIT");
728	else if (png_ptr->mode & PNG_HAVE_IDAT)
729	{
730	png_warning(png_ptr, "Invalid sBIT after IDAT");
731	png_crc_finish(png_ptr, length);
732	return;
733	}
734	else if (png_ptr->mode & PNG_HAVE_PLTE)
735	{
736	/* Should be an error, but we can cope with it */
737	png_warning(png_ptr, "Out of place sBIT chunk");
738	}
739	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
740	{
741	png_warning(png_ptr, "Duplicate sBIT chunk");
742	png_crc_finish(png_ptr, length);
743	return;
744	}
745
746	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
747	truelen = 3;
748	else
749	truelen = (png_size_t)png_ptr->channels;
750
751	if (length != truelen \|\| length > 4)
752	{
753	png_warning(png_ptr, "Incorrect sBIT chunk length");
754	png_crc_finish(png_ptr, length);
755	return;
756	}
757
758	png_crc_read(png_ptr, buf, truelen);
759	if (png_crc_finish(png_ptr, 0))
760	return;
761
762	if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
763	{
764	png_ptr->sig_bit.red = buf[0];
765	png_ptr->sig_bit.green = buf[1];
766	png_ptr->sig_bit.blue = buf[2];
767	png_ptr->sig_bit.alpha = buf[3];
768	}
769	else
770	{
771	png_ptr->sig_bit.gray = buf[0];
772	png_ptr->sig_bit.red = buf[0];
773	png_ptr->sig_bit.green = buf[0];
774	png_ptr->sig_bit.blue = buf[0];
775	png_ptr->sig_bit.alpha = buf[1];
776	}
777	png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
778	}
779	#endif
780
781	#if defined(PNG_READ_cHRM_SUPPORTED)
782	void /* PRIVATE */
783	png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
784	{
785	png_byte buf[32];
786	#ifdef PNG_FLOATING_POINT_SUPPORTED
787	float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
788	#endif
789	png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
790	int_y_green, int_x_blue, int_y_blue;
791
792	png_uint_32 uint_x, uint_y;
793
794	png_debug(1, "in png_handle_cHRM");
795
796	if (!(png_ptr->mode & PNG_HAVE_IHDR))
797	png_error(png_ptr, "Missing IHDR before cHRM");
798	else if (png_ptr->mode & PNG_HAVE_IDAT)
799	{
800	png_warning(png_ptr, "Invalid cHRM after IDAT");
801	png_crc_finish(png_ptr, length);
802	return;
803	}
804	else if (png_ptr->mode & PNG_HAVE_PLTE)
805	/* Should be an error, but we can cope with it */
806	png_warning(png_ptr, "Missing PLTE before cHRM");
807
808	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
809	#if defined(PNG_READ_sRGB_SUPPORTED)
810	&& !(info_ptr->valid & PNG_INFO_sRGB)
811	#endif
812	)
813	{
814	png_warning(png_ptr, "Duplicate cHRM chunk");
815	png_crc_finish(png_ptr, length);
816	return;
817	}
818
819	if (length != 32)
820	{
821	png_warning(png_ptr, "Incorrect cHRM chunk length");
822	png_crc_finish(png_ptr, length);
823	return;
824	}
825
826	png_crc_read(png_ptr, buf, 32);
827	if (png_crc_finish(png_ptr, 0))
828	return;
829
830	uint_x = png_get_uint_32(buf);
831	uint_y = png_get_uint_32(buf + 4);
832	int_x_white = (png_fixed_point)uint_x;
833	int_y_white = (png_fixed_point)uint_y;
834
835	uint_x = png_get_uint_32(buf + 8);
836	uint_y = png_get_uint_32(buf + 12);
837	int_x_red = (png_fixed_point)uint_x;
838	int_y_red = (png_fixed_point)uint_y;
839
840	uint_x = png_get_uint_32(buf + 16);
841	uint_y = png_get_uint_32(buf + 20);
842	int_x_green = (png_fixed_point)uint_x;
843	int_y_green = (png_fixed_point)uint_y;
844
845	uint_x = png_get_uint_32(buf + 24);
846	uint_y = png_get_uint_32(buf + 28);
847	int_x_blue = (png_fixed_point)uint_x;
848	int_y_blue = (png_fixed_point)uint_y;
849
850	#ifdef PNG_FLOATING_POINT_SUPPORTED
851	white_x = (float)int_x_white / (float)100000.0;
852	white_y = (float)int_y_white / (float)100000.0;
853	red_x = (float)int_x_red / (float)100000.0;
854	red_y = (float)int_y_red / (float)100000.0;
855	green_x = (float)int_x_green / (float)100000.0;
856	green_y = (float)int_y_green / (float)100000.0;
857	blue_x = (float)int_x_blue / (float)100000.0;
858	blue_y = (float)int_y_blue / (float)100000.0;
859	#endif
860
861	#if defined(PNG_READ_sRGB_SUPPORTED)
862	if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
863	{
864	if (PNG_OUT_OF_RANGE(int_x_white, 31270, 1000) \|\|
865	PNG_OUT_OF_RANGE(int_y_white, 32900, 1000) \|\|
866	PNG_OUT_OF_RANGE(int_x_red, 64000L, 1000) \|\|
867	PNG_OUT_OF_RANGE(int_y_red, 33000, 1000) \|\|
868	PNG_OUT_OF_RANGE(int_x_green, 30000, 1000) \|\|
869	PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) \|\|
870	PNG_OUT_OF_RANGE(int_x_blue, 15000, 1000) \|\|
871	PNG_OUT_OF_RANGE(int_y_blue, 6000, 1000))
872	{
873	png_warning(png_ptr,
874	"Ignoring incorrect cHRM value when sRGB is also present");
875	#ifndef PNG_NO_CONSOLE_IO
876	#ifdef PNG_FLOATING_POINT_SUPPORTED
877	fprintf(stderr, "wx=%f, wy=%f, rx=%f, ry=%f\n",
878	white_x, white_y, red_x, red_y);
879	fprintf(stderr, "gx=%f, gy=%f, bx=%f, by=%f\n",
880	green_x, green_y, blue_x, blue_y);
881	#else
882	fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
883	int_x_white, int_y_white, int_x_red, int_y_red);
884	fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
885	int_x_green, int_y_green, int_x_blue, int_y_blue);
886	#endif
887	#endif /* PNG_NO_CONSOLE_IO */
888	}
889	return;
890	}
891	#endif /* PNG_READ_sRGB_SUPPORTED */
892
893	#ifdef PNG_FLOATING_POINT_SUPPORTED
894	png_set_cHRM(png_ptr, info_ptr,
895	white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
896	#endif
897	#ifdef PNG_FIXED_POINT_SUPPORTED
898	png_set_cHRM_fixed(png_ptr, info_ptr,
899	int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
900	int_y_green, int_x_blue, int_y_blue);
901	#endif
902	}
903	#endif
904
905	#if defined(PNG_READ_sRGB_SUPPORTED)
906	void /* PRIVATE */
907	png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
908	{
909	int intent;
910	png_byte buf[1];
911
912	png_debug(1, "in png_handle_sRGB");
913
914	if (!(png_ptr->mode & PNG_HAVE_IHDR))
915	png_error(png_ptr, "Missing IHDR before sRGB");
916	else if (png_ptr->mode & PNG_HAVE_IDAT)
917	{
918	png_warning(png_ptr, "Invalid sRGB after IDAT");
919	png_crc_finish(png_ptr, length);
920	return;
921	}
922	else if (png_ptr->mode & PNG_HAVE_PLTE)
923	/* Should be an error, but we can cope with it */
924	png_warning(png_ptr, "Out of place sRGB chunk");
925
926	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
927	{
928	png_warning(png_ptr, "Duplicate sRGB chunk");
929	png_crc_finish(png_ptr, length);
930	return;
931	}
932
933	if (length != 1)
934	{
935	png_warning(png_ptr, "Incorrect sRGB chunk length");
936	png_crc_finish(png_ptr, length);
937	return;
938	}
939
940	png_crc_read(png_ptr, buf, 1);
941	if (png_crc_finish(png_ptr, 0))
942	return;
943
944	intent = buf[0];
945	/* Check for bad intent */
946	if (intent >= PNG_sRGB_INTENT_LAST)
947	{
948	png_warning(png_ptr, "Unknown sRGB intent");
949	return;
950	}
951
952	#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
953	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
954	{
955	png_fixed_point igamma;
956	#ifdef PNG_FIXED_POINT_SUPPORTED
957	igamma=info_ptr->int_gamma;
958	#else
959	# ifdef PNG_FLOATING_POINT_SUPPORTED
960	igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
961	# endif
962	#endif
963	if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
964	{
965	png_warning(png_ptr,
966	"Ignoring incorrect gAMA value when sRGB is also present");
967	#ifndef PNG_NO_CONSOLE_IO
968	# ifdef PNG_FIXED_POINT_SUPPORTED
969	fprintf(stderr, "incorrect gamma=(%d/100000)\n",
970	(int)png_ptr->int_gamma);
971	# else
972	# ifdef PNG_FLOATING_POINT_SUPPORTED
973	fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
974	# endif
975	# endif
976	#endif
977	}
978	}
979	#endif /* PNG_READ_gAMA_SUPPORTED */
980
981	#ifdef PNG_READ_cHRM_SUPPORTED
982	#ifdef PNG_FIXED_POINT_SUPPORTED
983	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
984	if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270, 1000) \|\|
985	PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900, 1000) \|\|
986	PNG_OUT_OF_RANGE(info_ptr->int_x_red, 64000L, 1000) \|\|
987	PNG_OUT_OF_RANGE(info_ptr->int_y_red, 33000, 1000) \|\|
988	PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000, 1000) \|\|
989	PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) \|\|
990	PNG_OUT_OF_RANGE(info_ptr->int_x_blue, 15000, 1000) \|\|
991	PNG_OUT_OF_RANGE(info_ptr->int_y_blue, 6000, 1000))
992	{
993	png_warning(png_ptr,
994	"Ignoring incorrect cHRM value when sRGB is also present");
995	}
996	#endif /* PNG_FIXED_POINT_SUPPORTED */
997	#endif /* PNG_READ_cHRM_SUPPORTED */
998
999	png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
1000	}
1001	#endif /* PNG_READ_sRGB_SUPPORTED */
1002
1003	#if defined(PNG_READ_iCCP_SUPPORTED)
1004	void /* PRIVATE */
1005	png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1006	/* Note: this does not properly handle chunks that are > 64K under DOS */
1007	{
1008	png_byte compression_type;
1009	png_bytep pC;
1010	png_charp profile;
1011	png_uint_32 skip = 0;
1012	png_uint_32 profile_size, profile_length;
1013	png_size_t slength, prefix_length, data_length;
1014
1015	png_debug(1, "in png_handle_iCCP");
1016
1017	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1018	png_error(png_ptr, "Missing IHDR before iCCP");
1019	else if (png_ptr->mode & PNG_HAVE_IDAT)
1020	{
1021	png_warning(png_ptr, "Invalid iCCP after IDAT");
1022	png_crc_finish(png_ptr, length);
1023	return;
1024	}
1025	else if (png_ptr->mode & PNG_HAVE_PLTE)
1026	/* Should be an error, but we can cope with it */
1027	png_warning(png_ptr, "Out of place iCCP chunk");
1028
1029	if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
1030	{
1031	png_warning(png_ptr, "Duplicate iCCP chunk");
1032	png_crc_finish(png_ptr, length);
1033	return;
1034	}
1035
1036	#ifdef PNG_MAX_MALLOC_64K
1037	if (length > (png_uint_32)65535L)
1038	{
1039	png_warning(png_ptr, "iCCP chunk too large to fit in memory");
1040	skip = length - (png_uint_32)65535L;
1041	length = (png_uint_32)65535L;
1042	}
1043	#endif
1044
1045	png_free(png_ptr, png_ptr->chunkdata);
1046	png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
1047	slength = (png_size_t)length;
1048	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
1049
1050	if (png_crc_finish(png_ptr, skip))
1051	{
1052	png_free(png_ptr, png_ptr->chunkdata);
1053	png_ptr->chunkdata = NULL;
1054	return;
1055	}
1056
1057	png_ptr->chunkdata[slength] = 0x00;
1058
1059	for (profile = png_ptr->chunkdata; *profile; profile++)
1060	/* Empty loop to find end of name */ ;
1061
1062	++profile;
1063
1064	/* There should be at least one zero (the compression type byte)
1065	* following the separator, and we should be on it
1066	*/
1067	if ( profile >= png_ptr->chunkdata + slength - 1)
1068	{
1069	png_free(png_ptr, png_ptr->chunkdata);
1070	png_ptr->chunkdata = NULL;
1071	png_warning(png_ptr, "Malformed iCCP chunk");
1072	return;
1073	}
1074
1075	/* Compression_type should always be zero */
1076	compression_type = *profile++;
1077	if (compression_type)
1078	{
1079	png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
1080	compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
1081	wrote nonzero) */
1082	}
1083
1084	prefix_length = profile - png_ptr->chunkdata;
1085	png_decompress_chunk(png_ptr, compression_type,
1086	slength, prefix_length, &data_length);
1087
1088	profile_length = data_length - prefix_length;
1089
1090	if ( prefix_length > data_length \|\| profile_length < 4)
1091	{
1092	png_free(png_ptr, png_ptr->chunkdata);
1093	png_ptr->chunkdata = NULL;
1094	png_warning(png_ptr, "Profile size field missing from iCCP chunk");
1095	return;
1096	}
1097
1098	/* Check the profile_size recorded in the first 32 bits of the ICC profile */
1099	pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
1100	profile_size = ((*(pC ))<<24) \|
1101	((*(pC + 1))<<16) \|
1102	((*(pC + 2))<< 8) \|
1103	((*(pC + 3)) );
1104
1105	if (profile_size < profile_length)
1106	profile_length = profile_size;
1107
1108	if (profile_size > profile_length)
1109	{
1110	png_free(png_ptr, png_ptr->chunkdata);
1111	png_ptr->chunkdata = NULL;
1112	png_warning(png_ptr, "Ignoring truncated iCCP profile.");
1113	return;
1114	}
1115
1116	png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
1117	compression_type, png_ptr->chunkdata + prefix_length, profile_length);
1118	png_free(png_ptr, png_ptr->chunkdata);
1119	png_ptr->chunkdata = NULL;
1120	}
1121	#endif /* PNG_READ_iCCP_SUPPORTED */
1122
1123	#if defined(PNG_READ_sPLT_SUPPORTED)
1124	void /* PRIVATE */
1125	png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1126	/* Note: this does not properly handle chunks that are > 64K under DOS */
1127	{
1128	png_bytep entry_start;
1129	png_sPLT_t new_palette;
1130	#ifdef PNG_NO_POINTER_INDEXING
1131	png_sPLT_entryp pp;
1132	#endif
1133	int data_length, entry_size, i;
1134	png_uint_32 skip = 0;
1135	png_size_t slength;
1136
1137	png_debug(1, "in png_handle_sPLT");
1138
1139
1140	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1141	png_error(png_ptr, "Missing IHDR before sPLT");
1142	else if (png_ptr->mode & PNG_HAVE_IDAT)
1143	{
1144	png_warning(png_ptr, "Invalid sPLT after IDAT");
1145	png_crc_finish(png_ptr, length);
1146	return;
1147	}
1148
1149	#ifdef PNG_MAX_MALLOC_64K
1150	if (length > (png_uint_32)65535L)
1151	{
1152	png_warning(png_ptr, "sPLT chunk too large to fit in memory");
1153	skip = length - (png_uint_32)65535L;
1154	length = (png_uint_32)65535L;
1155	}
1156	#endif
1157
1158	png_free(png_ptr, png_ptr->chunkdata);
1159	png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
1160	slength = (png_size_t)length;
1161	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
1162
1163	if (png_crc_finish(png_ptr, skip))
1164	{
1165	png_free(png_ptr, png_ptr->chunkdata);
1166	png_ptr->chunkdata = NULL;
1167	return;
1168	}
1169
1170	png_ptr->chunkdata[slength] = 0x00;
1171
1172	for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; entry_start++)
1173	/* Empty loop to find end of name */ ;
1174	++entry_start;
1175
1176	/* A sample depth should follow the separator, and we should be on it */
1177	if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
1178	{
1179	png_free(png_ptr, png_ptr->chunkdata);
1180	png_ptr->chunkdata = NULL;
1181	png_warning(png_ptr, "malformed sPLT chunk");
1182	return;
1183	}
1184
1185	new_palette.depth = *entry_start++;
1186	entry_size = (new_palette.depth == 8 ? 6 : 10);
1187	data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));
1188
1189	/* Integrity-check the data length */
1190	if (data_length % entry_size)
1191	{
1192	png_free(png_ptr, png_ptr->chunkdata);
1193	png_ptr->chunkdata = NULL;
1194	png_warning(png_ptr, "sPLT chunk has bad length");
1195	return;
1196	}
1197
1198	new_palette.nentries = (png_int_32) ( data_length / entry_size);
1199	if ((png_uint_32) new_palette.nentries >
1200	(png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
1201	{
1202	png_warning(png_ptr, "sPLT chunk too long");
1203	return;
1204	}
1205	new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
1206	png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
1207	if (new_palette.entries == NULL)
1208	{
1209	png_warning(png_ptr, "sPLT chunk requires too much memory");
1210	return;
1211	}
1212
1213	#ifndef PNG_NO_POINTER_INDEXING
1214	for (i = 0; i < new_palette.nentries; i++)
1215	{
1216	png_sPLT_entryp pp = new_palette.entries + i;
1217
1218	if (new_palette.depth == 8)
1219	{
1220	pp->red = *entry_start++;
1221	pp->green = *entry_start++;
1222	pp->blue = *entry_start++;
1223	pp->alpha = *entry_start++;
1224	}
1225	else
1226	{
1227	pp->red = png_get_uint_16(entry_start); entry_start += 2;
1228	pp->green = png_get_uint_16(entry_start); entry_start += 2;
1229	pp->blue = png_get_uint_16(entry_start); entry_start += 2;
1230	pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
1231	}
1232	pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
1233	}
1234	#else
1235	pp = new_palette.entries;
1236	for (i = 0; i < new_palette.nentries; i++)
1237	{
1238
1239	if (new_palette.depth == 8)
1240	{
1241	pp[i].red = *entry_start++;
1242	pp[i].green = *entry_start++;
1243	pp[i].blue = *entry_start++;
1244	pp[i].alpha = *entry_start++;
1245	}
1246	else
1247	{
1248	pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
1249	pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
1250	pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
1251	pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
1252	}
1253	pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
1254	}
1255	#endif
1256
1257	/* Discard all chunk data except the name and stash that */
1258	new_palette.name = png_ptr->chunkdata;
1259
1260	png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
1261
1262	png_free(png_ptr, png_ptr->chunkdata);
1263	png_ptr->chunkdata = NULL;
1264	png_free(png_ptr, new_palette.entries);
1265	}
1266	#endif /* PNG_READ_sPLT_SUPPORTED */
1267
1268	#if defined(PNG_READ_tRNS_SUPPORTED)
1269	void /* PRIVATE */
1270	png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1271	{
1272	png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
1273
1274	png_debug(1, "in png_handle_tRNS");
1275
1276	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1277	png_error(png_ptr, "Missing IHDR before tRNS");
1278	else if (png_ptr->mode & PNG_HAVE_IDAT)
1279	{
1280	png_warning(png_ptr, "Invalid tRNS after IDAT");
1281	png_crc_finish(png_ptr, length);
1282	return;
1283	}
1284	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
1285	{
1286	png_warning(png_ptr, "Duplicate tRNS chunk");
1287	png_crc_finish(png_ptr, length);
1288	return;
1289	}
1290
1291	if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
1292	{
1293	png_byte buf[2];
1294
1295	if (length != 2)
1296	{
1297	png_warning(png_ptr, "Incorrect tRNS chunk length");
1298	png_crc_finish(png_ptr, length);
1299	return;
1300	}
1301
1302	png_crc_read(png_ptr, buf, 2);
1303	png_ptr->num_trans = 1;
1304	png_ptr->trans_values.gray = png_get_uint_16(buf);
1305	}
1306	else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
1307	{
1308	png_byte buf[6];
1309
1310	if (length != 6)
1311	{
1312	png_warning(png_ptr, "Incorrect tRNS chunk length");
1313	png_crc_finish(png_ptr, length);
1314	return;
1315	}
1316	png_crc_read(png_ptr, buf, (png_size_t)length);
1317	png_ptr->num_trans = 1;
1318	png_ptr->trans_values.red = png_get_uint_16(buf);
1319	png_ptr->trans_values.green = png_get_uint_16(buf + 2);
1320	png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
1321	}
1322	else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1323	{
1324	if (!(png_ptr->mode & PNG_HAVE_PLTE))
1325	{
1326	/* Should be an error, but we can cope with it. */
1327	png_warning(png_ptr, "Missing PLTE before tRNS");
1328	}
1329	if (length > (png_uint_32)png_ptr->num_palette \|\|
1330	length > PNG_MAX_PALETTE_LENGTH)
1331	{
1332	png_warning(png_ptr, "Incorrect tRNS chunk length");
1333	png_crc_finish(png_ptr, length);
1334	return;
1335	}
1336	if (length == 0)
1337	{
1338	png_warning(png_ptr, "Zero length tRNS chunk");
1339	png_crc_finish(png_ptr, length);
1340	return;
1341	}
1342	png_crc_read(png_ptr, readbuf, (png_size_t)length);
1343	png_ptr->num_trans = (png_uint_16)length;
1344	}
1345	else
1346	{
1347	png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
1348	png_crc_finish(png_ptr, length);
1349	return;
1350	}
1351
1352	if (png_crc_finish(png_ptr, 0))
1353	{
1354	png_ptr->num_trans = 0;
1355	return;
1356	}
1357
1358	png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
1359	&(png_ptr->trans_values));
1360	}
1361	#endif
1362
1363	#if defined(PNG_READ_bKGD_SUPPORTED)
1364	void /* PRIVATE */
1365	png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1366	{
1367	png_size_t truelen;
1368	png_byte buf[6];
1369
1370	png_debug(1, "in png_handle_bKGD");
1371
1372	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1373	png_error(png_ptr, "Missing IHDR before bKGD");
1374	else if (png_ptr->mode & PNG_HAVE_IDAT)
1375	{
1376	png_warning(png_ptr, "Invalid bKGD after IDAT");
1377	png_crc_finish(png_ptr, length);
1378	return;
1379	}
1380	else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
1381	!(png_ptr->mode & PNG_HAVE_PLTE))
1382	{
1383	png_warning(png_ptr, "Missing PLTE before bKGD");
1384	png_crc_finish(png_ptr, length);
1385	return;
1386	}
1387	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
1388	{
1389	png_warning(png_ptr, "Duplicate bKGD chunk");
1390	png_crc_finish(png_ptr, length);
1391	return;
1392	}
1393
1394	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1395	truelen = 1;
1396	else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
1397	truelen = 6;
1398	else
1399	truelen = 2;
1400
1401	if (length != truelen)
1402	{
1403	png_warning(png_ptr, "Incorrect bKGD chunk length");
1404	png_crc_finish(png_ptr, length);
1405	return;
1406	}
1407
1408	png_crc_read(png_ptr, buf, truelen);
1409	if (png_crc_finish(png_ptr, 0))
1410	return;
1411
1412	/* We convert the index value into RGB components so that we can allow
1413	* arbitrary RGB values for background when we have transparency, and
1414	* so it is easy to determine the RGB values of the background color
1415	* from the info_ptr struct. */
1416	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1417	{
1418	png_ptr->background.index = buf[0];
1419	if (info_ptr && info_ptr->num_palette)
1420	{
1421	if (buf[0] >= info_ptr->num_palette)
1422	{
1423	png_warning(png_ptr, "Incorrect bKGD chunk index value");
1424	return;
1425	}
1426	png_ptr->background.red =
1427	(png_uint_16)png_ptr->palette[buf[0]].red;
1428	png_ptr->background.green =
1429	(png_uint_16)png_ptr->palette[buf[0]].green;
1430	png_ptr->background.blue =
1431	(png_uint_16)png_ptr->palette[buf[0]].blue;
1432	}
1433	}
1434	else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
1435	{
1436	png_ptr->background.red =
1437	png_ptr->background.green =
1438	png_ptr->background.blue =
1439	png_ptr->background.gray = png_get_uint_16(buf);
1440	}
1441	else
1442	{
1443	png_ptr->background.red = png_get_uint_16(buf);
1444	png_ptr->background.green = png_get_uint_16(buf + 2);
1445	png_ptr->background.blue = png_get_uint_16(buf + 4);
1446	}
1447
1448	png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
1449	}
1450	#endif
1451
1452	#if defined(PNG_READ_hIST_SUPPORTED)
1453	void /* PRIVATE */
1454	png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1455	{
1456	unsigned int num, i;
1457	png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
1458
1459	png_debug(1, "in png_handle_hIST");
1460
1461	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1462	png_error(png_ptr, "Missing IHDR before hIST");
1463	else if (png_ptr->mode & PNG_HAVE_IDAT)
1464	{
1465	png_warning(png_ptr, "Invalid hIST after IDAT");
1466	png_crc_finish(png_ptr, length);
1467	return;
1468	}
1469	else if (!(png_ptr->mode & PNG_HAVE_PLTE))
1470	{
1471	png_warning(png_ptr, "Missing PLTE before hIST");
1472	png_crc_finish(png_ptr, length);
1473	return;
1474	}
1475	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
1476	{
1477	png_warning(png_ptr, "Duplicate hIST chunk");
1478	png_crc_finish(png_ptr, length);
1479	return;
1480	}
1481
1482	num = length / 2 ;
1483	if (num != (unsigned int) png_ptr->num_palette \|\| num >
1484	(unsigned int) PNG_MAX_PALETTE_LENGTH)
1485	{
1486	png_warning(png_ptr, "Incorrect hIST chunk length");
1487	png_crc_finish(png_ptr, length);
1488	return;
1489	}
1490
1491	for (i = 0; i < num; i++)
1492	{
1493	png_byte buf[2];
1494
1495	png_crc_read(png_ptr, buf, 2);
1496	readbuf[i] = png_get_uint_16(buf);
1497	}
1498
1499	if (png_crc_finish(png_ptr, 0))
1500	return;
1501
1502	png_set_hIST(png_ptr, info_ptr, readbuf);
1503	}
1504	#endif
1505
1506	#if defined(PNG_READ_pHYs_SUPPORTED)
1507	void /* PRIVATE */
1508	png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1509	{
1510	png_byte buf[9];
1511	png_uint_32 res_x, res_y;
1512	int unit_type;
1513
1514	png_debug(1, "in png_handle_pHYs");
1515
1516	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1517	png_error(png_ptr, "Missing IHDR before pHYs");
1518	else if (png_ptr->mode & PNG_HAVE_IDAT)
1519	{
1520	png_warning(png_ptr, "Invalid pHYs after IDAT");
1521	png_crc_finish(png_ptr, length);
1522	return;
1523	}
1524	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
1525	{
1526	png_warning(png_ptr, "Duplicate pHYs chunk");
1527	png_crc_finish(png_ptr, length);
1528	return;
1529	}
1530
1531	if (length != 9)
1532	{
1533	png_warning(png_ptr, "Incorrect pHYs chunk length");
1534	png_crc_finish(png_ptr, length);
1535	return;
1536	}
1537
1538	png_crc_read(png_ptr, buf, 9);
1539	if (png_crc_finish(png_ptr, 0))
1540	return;
1541
1542	res_x = png_get_uint_32(buf);
1543	res_y = png_get_uint_32(buf + 4);
1544	unit_type = buf[8];
1545	png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
1546	}
1547	#endif
1548
1549	#if defined(PNG_READ_oFFs_SUPPORTED)
1550	void /* PRIVATE */
1551	png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1552	{
1553	png_byte buf[9];
1554	png_int_32 offset_x, offset_y;
1555	int unit_type;
1556
1557	png_debug(1, "in png_handle_oFFs");
1558
1559	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1560	png_error(png_ptr, "Missing IHDR before oFFs");
1561	else if (png_ptr->mode & PNG_HAVE_IDAT)
1562	{
1563	png_warning(png_ptr, "Invalid oFFs after IDAT");
1564	png_crc_finish(png_ptr, length);
1565	return;
1566	}
1567	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
1568	{
1569	png_warning(png_ptr, "Duplicate oFFs chunk");
1570	png_crc_finish(png_ptr, length);
1571	return;
1572	}
1573
1574	if (length != 9)
1575	{
1576	png_warning(png_ptr, "Incorrect oFFs chunk length");
1577	png_crc_finish(png_ptr, length);
1578	return;
1579	}
1580
1581	png_crc_read(png_ptr, buf, 9);
1582	if (png_crc_finish(png_ptr, 0))
1583	return;
1584
1585	offset_x = png_get_int_32(buf);
1586	offset_y = png_get_int_32(buf + 4);
1587	unit_type = buf[8];
1588	png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
1589	}
1590	#endif
1591
1592	#if defined(PNG_READ_pCAL_SUPPORTED)
1593	/* Read the pCAL chunk (described in the PNG Extensions document) */
1594	void /* PRIVATE */
1595	png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1596	{
1597	png_int_32 X0, X1;
1598	png_byte type, nparams;
1599	png_charp buf, units, endptr;
1600	png_charpp params;
1601	png_size_t slength;
1602	int i;
1603
1604	png_debug(1, "in png_handle_pCAL");
1605
1606	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1607	png_error(png_ptr, "Missing IHDR before pCAL");
1608	else if (png_ptr->mode & PNG_HAVE_IDAT)
1609	{
1610	png_warning(png_ptr, "Invalid pCAL after IDAT");
1611	png_crc_finish(png_ptr, length);
1612	return;
1613	}
1614	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
1615	{
1616	png_warning(png_ptr, "Duplicate pCAL chunk");
1617	png_crc_finish(png_ptr, length);
1618	return;
1619	}
1620
1621	png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)",
1622	length + 1);
1623	png_free(png_ptr, png_ptr->chunkdata);
1624	png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
1625	if (png_ptr->chunkdata == NULL)
1626	{
1627	png_warning(png_ptr, "No memory for pCAL purpose.");
1628	return;
1629	}
1630	slength = (png_size_t)length;
1631	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
1632
1633	if (png_crc_finish(png_ptr, 0))
1634	{
1635	png_free(png_ptr, png_ptr->chunkdata);
1636	png_ptr->chunkdata = NULL;
1637	return;
1638	}
1639
1640	png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
1641
1642	png_debug(3, "Finding end of pCAL purpose string");
1643	for (buf = png_ptr->chunkdata; *buf; buf++)
1644	/* Empty loop */ ;
1645
1646	endptr = png_ptr->chunkdata + slength;
1647
1648	/* We need to have at least 12 bytes after the purpose string
1649	in order to get the parameter information. */
1650	if (endptr <= buf + 12)
1651	{
1652	png_warning(png_ptr, "Invalid pCAL data");
1653	png_free(png_ptr, png_ptr->chunkdata);
1654	png_ptr->chunkdata = NULL;
1655	return;
1656	}
1657
1658	png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
1659	X0 = png_get_int_32((png_bytep)buf+1);
1660	X1 = png_get_int_32((png_bytep)buf+5);
1661	type = buf[9];
1662	nparams = buf[10];
1663	units = buf + 11;
1664
1665	png_debug(3, "Checking pCAL equation type and number of parameters");
1666	/* Check that we have the right number of parameters for known
1667	equation types. */
1668	if ((type == PNG_EQUATION_LINEAR && nparams != 2) \|\|
1669	(type == PNG_EQUATION_BASE_E && nparams != 3) \|\|
1670	(type == PNG_EQUATION_ARBITRARY && nparams != 3) \|\|
1671	(type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
1672	{
1673	png_warning(png_ptr, "Invalid pCAL parameters for equation type");
1674	png_free(png_ptr, png_ptr->chunkdata);
1675	png_ptr->chunkdata = NULL;
1676	return;
1677	}
1678	else if (type >= PNG_EQUATION_LAST)
1679	{
1680	png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1681	}
1682
1683	for (buf = units; *buf; buf++)
1684	/* Empty loop to move past the units string. */ ;
1685
1686	png_debug(3, "Allocating pCAL parameters array");
1687	params = (png_charpp)png_malloc_warn(png_ptr,
1688	(png_uint_32)(nparams * png_sizeof(png_charp))) ;
1689	if (params == NULL)
1690	{
1691	png_free(png_ptr, png_ptr->chunkdata);
1692	png_ptr->chunkdata = NULL;
1693	png_warning(png_ptr, "No memory for pCAL params.");
1694	return;
1695	}
1696
1697	/* Get pointers to the start of each parameter string. */
1698	for (i = 0; i < (int)nparams; i++)
1699	{
1700	buf++; /* Skip the null string terminator from previous parameter. */
1701
1702	png_debug1(3, "Reading pCAL parameter %d", i);
1703	for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
1704	/* Empty loop to move past each parameter string */ ;
1705
1706	/* Make sure we haven't run out of data yet */
1707	if (buf > endptr)
1708	{
1709	png_warning(png_ptr, "Invalid pCAL data");
1710	png_free(png_ptr, png_ptr->chunkdata);
1711	png_ptr->chunkdata = NULL;
1712	png_free(png_ptr, params);
1713	return;
1714	}
1715	}
1716
1717	png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
1718	units, params);
1719
1720	png_free(png_ptr, png_ptr->chunkdata);
1721	png_ptr->chunkdata = NULL;
1722	png_free(png_ptr, params);
1723	}
1724	#endif
1725
1726	#if defined(PNG_READ_sCAL_SUPPORTED)
1727	/* Read the sCAL chunk */
1728	void /* PRIVATE */
1729	png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1730	{
1731	png_charp ep;
1732	#ifdef PNG_FLOATING_POINT_SUPPORTED
1733	double width, height;
1734	png_charp vp;
1735	#else
1736	#ifdef PNG_FIXED_POINT_SUPPORTED
1737	png_charp swidth, sheight;
1738	#endif
1739	#endif
1740	png_size_t slength;
1741
1742	png_debug(1, "in png_handle_sCAL");
1743
1744	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1745	png_error(png_ptr, "Missing IHDR before sCAL");
1746	else if (png_ptr->mode & PNG_HAVE_IDAT)
1747	{
1748	png_warning(png_ptr, "Invalid sCAL after IDAT");
1749	png_crc_finish(png_ptr, length);
1750	return;
1751	}
1752	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
1753	{
1754	png_warning(png_ptr, "Duplicate sCAL chunk");
1755	png_crc_finish(png_ptr, length);
1756	return;
1757	}
1758
1759	png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)",
1760	length + 1);
1761	png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
1762	if (png_ptr->chunkdata == NULL)
1763	{
1764	png_warning(png_ptr, "Out of memory while processing sCAL chunk");
1765	return;
1766	}
1767	slength = (png_size_t)length;
1768	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
1769
1770	if (png_crc_finish(png_ptr, 0))
1771	{
1772	png_free(png_ptr, png_ptr->chunkdata);
1773	png_ptr->chunkdata = NULL;
1774	return;
1775	}
1776
1777	png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
1778
1779	ep = png_ptr->chunkdata + 1; /* Skip unit byte */
1780
1781	#ifdef PNG_FLOATING_POINT_SUPPORTED
1782	width = png_strtod(png_ptr, ep, &vp);
1783	if (*vp)
1784	{
1785	png_warning(png_ptr, "malformed width string in sCAL chunk");
1786	return;
1787	}
1788	#else
1789	#ifdef PNG_FIXED_POINT_SUPPORTED
1790	swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
1791	if (swidth == NULL)
1792	{
1793	png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
1794	return;
1795	}
1796	png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
1797	#endif
1798	#endif
1799
1800	for (ep = png_ptr->chunkdata; *ep; ep++)
1801	/* Empty loop */ ;
1802	ep++;
1803
1804	if (png_ptr->chunkdata + slength < ep)
1805	{
1806	png_warning(png_ptr, "Truncated sCAL chunk");
1807	#if defined(PNG_FIXED_POINT_SUPPORTED) && \
1808	!defined(PNG_FLOATING_POINT_SUPPORTED)
1809	png_free(png_ptr, swidth);
1810	#endif
1811	png_free(png_ptr, png_ptr->chunkdata);
1812	png_ptr->chunkdata = NULL;
1813	return;
1814	}
1815
1816	#ifdef PNG_FLOATING_POINT_SUPPORTED
1817	height = png_strtod(png_ptr, ep, &vp);
1818	if (*vp)
1819	{
1820	png_warning(png_ptr, "malformed height string in sCAL chunk");
1821	return;
1822	}
1823	#else
1824	#ifdef PNG_FIXED_POINT_SUPPORTED
1825	sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
1826	if (sheight == NULL)
1827	{
1828	png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
1829	return;
1830	}
1831	png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
1832	#endif
1833	#endif
1834
1835	if (png_ptr->chunkdata + slength < ep
1836	#ifdef PNG_FLOATING_POINT_SUPPORTED
1837	\|\| width <= 0. \|\| height <= 0.
1838	#endif
1839	)
1840	{
1841	png_warning(png_ptr, "Invalid sCAL data");
1842	png_free(png_ptr, png_ptr->chunkdata);
1843	png_ptr->chunkdata = NULL;
1844	#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
1845	png_free(png_ptr, swidth);
1846	png_free(png_ptr, sheight);
1847	#endif
1848	return;
1849	}
1850
1851
1852	#ifdef PNG_FLOATING_POINT_SUPPORTED
1853	png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height);
1854	#else
1855	#ifdef PNG_FIXED_POINT_SUPPORTED
1856	png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight);
1857	#endif
1858	#endif
1859
1860	png_free(png_ptr, png_ptr->chunkdata);
1861	png_ptr->chunkdata = NULL;
1862	#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
1863	png_free(png_ptr, swidth);
1864	png_free(png_ptr, sheight);
1865	#endif
1866	}
1867	#endif
1868
1869	#if defined(PNG_READ_tIME_SUPPORTED)
1870	void /* PRIVATE */
1871	png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1872	{
1873	png_byte buf[7];
1874	png_time mod_time;
1875
1876	png_debug(1, "in png_handle_tIME");
1877
1878	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1879	png_error(png_ptr, "Out of place tIME chunk");
1880	else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
1881	{
1882	png_warning(png_ptr, "Duplicate tIME chunk");
1883	png_crc_finish(png_ptr, length);
1884	return;
1885	}
1886
1887	if (png_ptr->mode & PNG_HAVE_IDAT)
1888	png_ptr->mode \|= PNG_AFTER_IDAT;
1889
1890	if (length != 7)
1891	{
1892	png_warning(png_ptr, "Incorrect tIME chunk length");
1893	png_crc_finish(png_ptr, length);
1894	return;
1895	}
1896
1897	png_crc_read(png_ptr, buf, 7);
1898	if (png_crc_finish(png_ptr, 0))
1899	return;
1900
1901	mod_time.second = buf[6];
1902	mod_time.minute = buf[5];
1903	mod_time.hour = buf[4];
1904	mod_time.day = buf[3];
1905	mod_time.month = buf[2];
1906	mod_time.year = png_get_uint_16(buf);
1907
1908	png_set_tIME(png_ptr, info_ptr, &mod_time);
1909	}
1910	#endif
1911
1912	#if defined(PNG_READ_tEXt_SUPPORTED)
1913	/* Note: this does not properly handle chunks that are > 64K under DOS */
1914	void /* PRIVATE */
1915	png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1916	{
1917	png_textp text_ptr;
1918	png_charp key;
1919	png_charp text;
1920	png_uint_32 skip = 0;
1921	png_size_t slength;
1922	int ret;
1923
1924	png_debug(1, "in png_handle_tEXt");
1925
1926
1927	if (!(png_ptr->mode & PNG_HAVE_IHDR))
1928	png_error(png_ptr, "Missing IHDR before tEXt");
1929
1930	if (png_ptr->mode & PNG_HAVE_IDAT)
1931	png_ptr->mode \|= PNG_AFTER_IDAT;
1932
1933	#ifdef PNG_MAX_MALLOC_64K
1934	if (length > (png_uint_32)65535L)
1935	{
1936	png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1937	skip = length - (png_uint_32)65535L;
1938	length = (png_uint_32)65535L;
1939	}
1940	#endif
1941
1942	png_free(png_ptr, png_ptr->chunkdata);
1943
1944	png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
1945	if (png_ptr->chunkdata == NULL)
1946	{
1947	png_warning(png_ptr, "No memory to process text chunk.");
1948	return;
1949	}
1950	slength = (png_size_t)length;
1951	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
1952
1953	if (png_crc_finish(png_ptr, skip))
1954	{
1955	png_free(png_ptr, png_ptr->chunkdata);
1956	png_ptr->chunkdata = NULL;
1957	return;
1958	}
1959
1960	key = png_ptr->chunkdata;
1961
1962	key[slength] = 0x00;
1963
1964	for (text = key; *text; text++)
1965	/* Empty loop to find end of key */ ;
1966
1967	if (text != key + slength)
1968	text++;
1969
1970	text_ptr = (png_textp)png_malloc_warn(png_ptr,
1971	(png_uint_32)png_sizeof(png_text));
1972	if (text_ptr == NULL)
1973	{
1974	png_warning(png_ptr, "Not enough memory to process text chunk.");
1975	png_free(png_ptr, png_ptr->chunkdata);
1976	png_ptr->chunkdata = NULL;
1977	return;
1978	}
1979	text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1980	text_ptr->key = key;
1981	#ifdef PNG_iTXt_SUPPORTED
1982	text_ptr->lang = NULL;
1983	text_ptr->lang_key = NULL;
1984	text_ptr->itxt_length = 0;
1985	#endif
1986	text_ptr->text = text;
1987	text_ptr->text_length = png_strlen(text);
1988
1989	ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1990
1991	png_free(png_ptr, png_ptr->chunkdata);
1992	png_ptr->chunkdata = NULL;
1993	png_free(png_ptr, text_ptr);
1994	if (ret)
1995	png_warning(png_ptr, "Insufficient memory to process text chunk.");
1996	}
1997	#endif
1998
1999	#if defined(PNG_READ_zTXt_SUPPORTED)
2000	/* Note: this does not correctly handle chunks that are > 64K under DOS */
2001	void /* PRIVATE */
2002	png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
2003	{
2004	png_textp text_ptr;
2005	png_charp text;
2006	int comp_type;
2007	int ret;
2008	png_size_t slength, prefix_len, data_len;
2009
2010	png_debug(1, "in png_handle_zTXt");
2011
2012
2013	if (!(png_ptr->mode & PNG_HAVE_IHDR))
2014	png_error(png_ptr, "Missing IHDR before zTXt");
2015
2016	if (png_ptr->mode & PNG_HAVE_IDAT)
2017	png_ptr->mode \|= PNG_AFTER_IDAT;
2018
2019	#ifdef PNG_MAX_MALLOC_64K
2020	/* We will no doubt have problems with chunks even half this size, but
2021	there is no hard and fast rule to tell us where to stop. */
2022	if (length > (png_uint_32)65535L)
2023	{
2024	png_warning(png_ptr, "zTXt chunk too large to fit in memory");
2025	png_crc_finish(png_ptr, length);
2026	return;
2027	}
2028	#endif
2029
2030	png_free(png_ptr, png_ptr->chunkdata);
2031	png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
2032	if (png_ptr->chunkdata == NULL)
2033	{
2034	png_warning(png_ptr, "Out of memory processing zTXt chunk.");
2035	return;
2036	}
2037	slength = (png_size_t)length;
2038	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
2039	if (png_crc_finish(png_ptr, 0))
2040	{
2041	png_free(png_ptr, png_ptr->chunkdata);
2042	png_ptr->chunkdata = NULL;
2043	return;
2044	}
2045
2046	png_ptr->chunkdata[slength] = 0x00;
2047
2048	for (text = png_ptr->chunkdata; *text; text++)
2049	/* Empty loop */ ;
2050
2051	/* zTXt must have some text after the chunkdataword */
2052	if (text >= png_ptr->chunkdata + slength - 2)
2053	{
2054	png_warning(png_ptr, "Truncated zTXt chunk");
2055	png_free(png_ptr, png_ptr->chunkdata);
2056	png_ptr->chunkdata = NULL;
2057	return;
2058	}
2059	else
2060	{
2061	comp_type = *(++text);
2062	if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
2063	{
2064	png_warning(png_ptr, "Unknown compression type in zTXt chunk");
2065	comp_type = PNG_TEXT_COMPRESSION_zTXt;
2066	}
2067	text++; /* Skip the compression_method byte */
2068	}
2069	prefix_len = text - png_ptr->chunkdata;
2070
2071	png_decompress_chunk(png_ptr, comp_type,
2072	(png_size_t)length, prefix_len, &data_len);
2073
2074	text_ptr = (png_textp)png_malloc_warn(png_ptr,
2075	(png_uint_32)png_sizeof(png_text));
2076	if (text_ptr == NULL)
2077	{
2078	png_warning(png_ptr, "Not enough memory to process zTXt chunk.");
2079	png_free(png_ptr, png_ptr->chunkdata);
2080	png_ptr->chunkdata = NULL;
2081	return;
2082	}
2083	text_ptr->compression = comp_type;
2084	text_ptr->key = png_ptr->chunkdata;
2085	#ifdef PNG_iTXt_SUPPORTED
2086	text_ptr->lang = NULL;
2087	text_ptr->lang_key = NULL;
2088	text_ptr->itxt_length = 0;
2089	#endif
2090	text_ptr->text = png_ptr->chunkdata + prefix_len;
2091	text_ptr->text_length = data_len;
2092
2093	ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
2094
2095	png_free(png_ptr, text_ptr);
2096	png_free(png_ptr, png_ptr->chunkdata);
2097	png_ptr->chunkdata = NULL;
2098	if (ret)
2099	png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
2100	}
2101	#endif
2102
2103	#if defined(PNG_READ_iTXt_SUPPORTED)
2104	/* Note: this does not correctly handle chunks that are > 64K under DOS */
2105	void /* PRIVATE */
2106	png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
2107	{
2108	png_textp text_ptr;
2109	png_charp key, lang, text, lang_key;
2110	int comp_flag;
2111	int comp_type = 0;
2112	int ret;
2113	png_size_t slength, prefix_len, data_len;
2114
2115	png_debug(1, "in png_handle_iTXt");
2116
2117
2118	if (!(png_ptr->mode & PNG_HAVE_IHDR))
2119	png_error(png_ptr, "Missing IHDR before iTXt");
2120
2121	if (png_ptr->mode & PNG_HAVE_IDAT)
2122	png_ptr->mode \|= PNG_AFTER_IDAT;
2123
2124	#ifdef PNG_MAX_MALLOC_64K
2125	/* We will no doubt have problems with chunks even half this size, but
2126	there is no hard and fast rule to tell us where to stop. */
2127	if (length > (png_uint_32)65535L)
2128	{
2129	png_warning(png_ptr, "iTXt chunk too large to fit in memory");
2130	png_crc_finish(png_ptr, length);
2131	return;
2132	}
2133	#endif
2134
2135	png_free(png_ptr, png_ptr->chunkdata);
2136	png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
2137	if (png_ptr->chunkdata == NULL)
2138	{
2139	png_warning(png_ptr, "No memory to process iTXt chunk.");
2140	return;
2141	}
2142	slength = (png_size_t)length;
2143	png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
2144	if (png_crc_finish(png_ptr, 0))
2145	{
2146	png_free(png_ptr, png_ptr->chunkdata);
2147	png_ptr->chunkdata = NULL;
2148	return;
2149	}
2150
2151	png_ptr->chunkdata[slength] = 0x00;
2152
2153	for (lang = png_ptr->chunkdata; *lang; lang++)
2154	/* Empty loop */ ;
2155	lang++; /* Skip NUL separator */
2156
2157	/* iTXt must have a language tag (possibly empty), two compression bytes,
2158	* translated keyword (possibly empty), and possibly some text after the
2159	* keyword
2160	*/
2161
2162	if (lang >= png_ptr->chunkdata + slength - 3)
2163	{
2164	png_warning(png_ptr, "Truncated iTXt chunk");
2165	png_free(png_ptr, png_ptr->chunkdata);
2166	png_ptr->chunkdata = NULL;
2167	return;
2168	}
2169	else
2170	{
2171	comp_flag = *lang++;
2172	comp_type = *lang++;
2173	}
2174
2175	for (lang_key = lang; *lang_key; lang_key++)
2176	/* Empty loop */ ;
2177	lang_key++; /* Skip NUL separator */
2178
2179	if (lang_key >= png_ptr->chunkdata + slength)
2180	{
2181	png_warning(png_ptr, "Truncated iTXt chunk");
2182	png_free(png_ptr, png_ptr->chunkdata);
2183	png_ptr->chunkdata = NULL;
2184	return;
2185	}
2186
2187	for (text = lang_key; *text; text++)
2188	/* Empty loop */ ;
2189	text++; /* Skip NUL separator */
2190	if (text >= png_ptr->chunkdata + slength)
2191	{
2192	png_warning(png_ptr, "Malformed iTXt chunk");
2193	png_free(png_ptr, png_ptr->chunkdata);
2194	png_ptr->chunkdata = NULL;
2195	return;
2196	}
2197
2198	prefix_len = text - png_ptr->chunkdata;
2199
2200	key=png_ptr->chunkdata;
2201	if (comp_flag)
2202	png_decompress_chunk(png_ptr, comp_type,
2203	(size_t)length, prefix_len, &data_len);
2204	else
2205	data_len = png_strlen(png_ptr->chunkdata + prefix_len);
2206	text_ptr = (png_textp)png_malloc_warn(png_ptr,
2207	(png_uint_32)png_sizeof(png_text));
2208	if (text_ptr == NULL)
2209	{
2210	png_warning(png_ptr, "Not enough memory to process iTXt chunk.");
2211	png_free(png_ptr, png_ptr->chunkdata);
2212	png_ptr->chunkdata = NULL;
2213	return;
2214	}
2215	text_ptr->compression = (int)comp_flag + 1;
2216	text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
2217	text_ptr->lang = png_ptr->chunkdata + (lang - key);
2218	text_ptr->itxt_length = data_len;
2219	text_ptr->text_length = 0;
2220	text_ptr->key = png_ptr->chunkdata;
2221	text_ptr->text = png_ptr->chunkdata + prefix_len;
2222
2223	ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
2224
2225	png_free(png_ptr, text_ptr);
2226	png_free(png_ptr, png_ptr->chunkdata);
2227	png_ptr->chunkdata = NULL;
2228	if (ret)
2229	png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
2230	}
2231	#endif
2232
2233	/* This function is called when we haven't found a handler for a
2234	chunk. If there isn't a problem with the chunk itself (ie bad
2235	chunk name, CRC, or a critical chunk), the chunk is silently ignored
2236	-- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
2237	case it will be saved away to be written out later. */
2238	void /* PRIVATE */
2239	png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
2240	{
2241	png_uint_32 skip = 0;
2242
2243	png_debug(1, "in png_handle_unknown");
2244
2245
2246	if (png_ptr->mode & PNG_HAVE_IDAT)
2247	{
2248	#ifdef PNG_USE_LOCAL_ARRAYS
2249	PNG_CONST PNG_IDAT;
2250	#endif
2251	if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */
2252	png_ptr->mode \|= PNG_AFTER_IDAT;
2253	}
2254
2255	if (!(png_ptr->chunk_name[0] & 0x20))
2256	{
2257	#if defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2258	if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
2259	PNG_HANDLE_CHUNK_ALWAYS
2260	#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
2261	&& png_ptr->read_user_chunk_fn == NULL
2262	#endif
2263	)
2264	#endif
2265	png_chunk_error(png_ptr, "unknown critical chunk");
2266	}
2267
2268	#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
2269	if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
2270	#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
2271	\|\| (png_ptr->read_user_chunk_fn != NULL)
2272	#endif
2273	)
2274	{
2275	#ifdef PNG_MAX_MALLOC_64K
2276	if (length > (png_uint_32)65535L)
2277	{
2278	png_warning(png_ptr, "unknown chunk too large to fit in memory");
2279	skip = length - (png_uint_32)65535L;
2280	length = (png_uint_32)65535L;
2281	}
2282	#endif
2283	png_memcpy((png_charp)png_ptr->unknown_chunk.name,
2284	(png_charp)png_ptr->chunk_name,
2285	png_sizeof(png_ptr->unknown_chunk.name));
2286	png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] = '\0';
2287	png_ptr->unknown_chunk.size = (png_size_t)length;
2288	if (length == 0)
2289	png_ptr->unknown_chunk.data = NULL;
2290	else
2291	{
2292	png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
2293	png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
2294	}
2295	#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
2296	if (png_ptr->read_user_chunk_fn != NULL)
2297	{
2298	/* Callback to user unknown chunk handler */
2299	int ret;
2300	ret = (*(png_ptr->read_user_chunk_fn))
2301	(png_ptr, &png_ptr->unknown_chunk);
2302	if (ret < 0)
2303	png_chunk_error(png_ptr, "error in user chunk");
2304	if (ret == 0)
2305	{
2306	if (!(png_ptr->chunk_name[0] & 0x20))
2307	#if defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2308	if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
2309	PNG_HANDLE_CHUNK_ALWAYS)
2310	#endif
2311	png_chunk_error(png_ptr, "unknown critical chunk");
2312	png_set_unknown_chunks(png_ptr, info_ptr,
2313	&png_ptr->unknown_chunk, 1);
2314	}
2315	}
2316	else
2317	#endif
2318	png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
2319	png_free(png_ptr, png_ptr->unknown_chunk.data);
2320	png_ptr->unknown_chunk.data = NULL;
2321	}
2322	else
2323	#endif
2324	skip = length;
2325
2326	png_crc_finish(png_ptr, skip);
2327
2328	#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
2329	info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */
2330	#endif
2331	}
2332
2333	/* This function is called to verify that a chunk name is valid.
2334	This function can't have the "critical chunk check" incorporated
2335	into it, since in the future we will need to be able to call user
2336	functions to handle unknown critical chunks after we check that
2337	the chunk name itself is valid. */
2338
2339	#define isnonalpha(c) ((c) < 65 \|\| (c) > 122 \|\| ((c) > 90 && (c) < 97))
2340
2341	void /* PRIVATE */
2342	png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
2343	{
2344	png_debug(1, "in png_check_chunk_name");
2345	if (isnonalpha(chunk_name[0]) \|\| isnonalpha(chunk_name[1]) \|\|
2346	isnonalpha(chunk_name[2]) \|\| isnonalpha(chunk_name[3]))
2347	{
2348	png_chunk_error(png_ptr, "invalid chunk type");
2349	}
2350	}
2351
2352	/* Combines the row recently read in with the existing pixels in the
2353	row. This routine takes care of alpha and transparency if requested.
2354	This routine also handles the two methods of progressive display
2355	of interlaced images, depending on the mask value.
2356	The mask value describes which pixels are to be combined with
2357	the row. The pattern always repeats every 8 pixels, so just 8
2358	bits are needed. A one indicates the pixel is to be combined,
2359	a zero indicates the pixel is to be skipped. This is in addition
2360	to any alpha or transparency value associated with the pixel. If
2361	you want all pixels to be combined, pass 0xff (255) in mask. */
2362
2363	void /* PRIVATE */
2364	png_combine_row(png_structp png_ptr, png_bytep row, int mask)
2365	{
2366	png_debug(1, "in png_combine_row");
2367	if (mask == 0xff)
2368	{
2369	png_memcpy(row, png_ptr->row_buf + 1,
2370	PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
2371	}
2372	else
2373	{
2374	switch (png_ptr->row_info.pixel_depth)
2375	{
2376	case 1:
2377	{
2378	png_bytep sp = png_ptr->row_buf + 1;
2379	png_bytep dp = row;
2380	int s_inc, s_start, s_end;
2381	int m = 0x80;
2382	int shift;
2383	png_uint_32 i;
2384	png_uint_32 row_width = png_ptr->width;
2385
2386	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2387	if (png_ptr->transformations & PNG_PACKSWAP)
2388	{
2389	s_start = 0;
2390	s_end = 7;
2391	s_inc = 1;
2392	}
2393	else
2394	#endif
2395	{
2396	s_start = 7;
2397	s_end = 0;
2398	s_inc = -1;
2399	}
2400
2401	shift = s_start;
2402
2403	for (i = 0; i < row_width; i++)
2404	{
2405	if (m & mask)
2406	{
2407	int value;
2408
2409	value = (*sp >> shift) & 0x01;
2410	*dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
2411	*dp \|= (png_byte)(value << shift);
2412	}
2413
2414	if (shift == s_end)
2415	{
2416	shift = s_start;
2417	sp++;
2418	dp++;
2419	}
2420	else
2421	shift += s_inc;
2422
2423	if (m == 1)
2424	m = 0x80;
2425	else
2426	m >>= 1;
2427	}
2428	break;
2429	}
2430	case 2:
2431	{
2432	png_bytep sp = png_ptr->row_buf + 1;
2433	png_bytep dp = row;
2434	int s_start, s_end, s_inc;
2435	int m = 0x80;
2436	int shift;
2437	png_uint_32 i;
2438	png_uint_32 row_width = png_ptr->width;
2439	int value;
2440
2441	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2442	if (png_ptr->transformations & PNG_PACKSWAP)
2443	{
2444	s_start = 0;
2445	s_end = 6;
2446	s_inc = 2;
2447	}
2448	else
2449	#endif
2450	{
2451	s_start = 6;
2452	s_end = 0;
2453	s_inc = -2;
2454	}
2455
2456	shift = s_start;
2457
2458	for (i = 0; i < row_width; i++)
2459	{
2460	if (m & mask)
2461	{
2462	value = (*sp >> shift) & 0x03;
2463	*dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
2464	*dp \|= (png_byte)(value << shift);
2465	}
2466
2467	if (shift == s_end)
2468	{
2469	shift = s_start;
2470	sp++;
2471	dp++;
2472	}
2473	else
2474	shift += s_inc;
2475	if (m == 1)
2476	m = 0x80;
2477	else
2478	m >>= 1;
2479	}
2480	break;
2481	}
2482	case 4:
2483	{
2484	png_bytep sp = png_ptr->row_buf + 1;
2485	png_bytep dp = row;
2486	int s_start, s_end, s_inc;
2487	int m = 0x80;
2488	int shift;
2489	png_uint_32 i;
2490	png_uint_32 row_width = png_ptr->width;
2491	int value;
2492
2493	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2494	if (png_ptr->transformations & PNG_PACKSWAP)
2495	{
2496	s_start = 0;
2497	s_end = 4;
2498	s_inc = 4;
2499	}
2500	else
2501	#endif
2502	{
2503	s_start = 4;
2504	s_end = 0;
2505	s_inc = -4;
2506	}
2507	shift = s_start;
2508
2509	for (i = 0; i < row_width; i++)
2510	{
2511	if (m & mask)
2512	{
2513	value = (*sp >> shift) & 0xf;
2514	*dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
2515	*dp \|= (png_byte)(value << shift);
2516	}
2517
2518	if (shift == s_end)
2519	{
2520	shift = s_start;
2521	sp++;
2522	dp++;
2523	}
2524	else
2525	shift += s_inc;
2526	if (m == 1)
2527	m = 0x80;
2528	else
2529	m >>= 1;
2530	}
2531	break;
2532	}
2533	default:
2534	{
2535	png_bytep sp = png_ptr->row_buf + 1;
2536	png_bytep dp = row;
2537	png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
2538	png_uint_32 i;
2539	png_uint_32 row_width = png_ptr->width;
2540	png_byte m = 0x80;
2541
2542
2543	for (i = 0; i < row_width; i++)
2544	{
2545	if (m & mask)
2546	{
2547	png_memcpy(dp, sp, pixel_bytes);
2548	}
2549
2550	sp += pixel_bytes;
2551	dp += pixel_bytes;
2552
2553	if (m == 1)
2554	m = 0x80;
2555	else
2556	m >>= 1;
2557	}
2558	break;
2559	}
2560	}
2561	}
2562	}
2563
2564	#ifdef PNG_READ_INTERLACING_SUPPORTED
2565	/* OLD pre-1.0.9 interface:
2566	void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
2567	png_uint_32 transformations)
2568	*/
2569	void /* PRIVATE */
2570	png_do_read_interlace(png_structp png_ptr)
2571	{
2572	png_row_infop row_info = &(png_ptr->row_info);
2573	png_bytep row = png_ptr->row_buf + 1;
2574	int pass = png_ptr->pass;
2575	png_uint_32 transformations = png_ptr->transformations;
2576	#ifdef PNG_USE_LOCAL_ARRAYS
2577	/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2578	/* Offset to next interlace block */
2579	PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2580	#endif
2581
2582	png_debug(1, "in png_do_read_interlace");
2583	if (row != NULL && row_info != NULL)
2584	{
2585	png_uint_32 final_width;
2586
2587	final_width = row_info->width * png_pass_inc[pass];
2588
2589	switch (row_info->pixel_depth)
2590	{
2591	case 1:
2592	{
2593	png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
2594	png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
2595	int sshift, dshift;
2596	int s_start, s_end, s_inc;
2597	int jstop = png_pass_inc[pass];
2598	png_byte v;
2599	png_uint_32 i;
2600	int j;
2601
2602	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2603	if (transformations & PNG_PACKSWAP)
2604	{
2605	sshift = (int)((row_info->width + 7) & 0x07);
2606	dshift = (int)((final_width + 7) & 0x07);
2607	s_start = 7;
2608	s_end = 0;
2609	s_inc = -1;
2610	}
2611	else
2612	#endif
2613	{
2614	sshift = 7 - (int)((row_info->width + 7) & 0x07);
2615	dshift = 7 - (int)((final_width + 7) & 0x07);
2616	s_start = 0;
2617	s_end = 7;
2618	s_inc = 1;
2619	}
2620
2621	for (i = 0; i < row_info->width; i++)
2622	{
2623	v = (png_byte)((*sp >> sshift) & 0x01);
2624	for (j = 0; j < jstop; j++)
2625	{
2626	*dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
2627	*dp \|= (png_byte)(v << dshift);
2628	if (dshift == s_end)
2629	{
2630	dshift = s_start;
2631	dp--;
2632	}
2633	else
2634	dshift += s_inc;
2635	}
2636	if (sshift == s_end)
2637	{
2638	sshift = s_start;
2639	sp--;
2640	}
2641	else
2642	sshift += s_inc;
2643	}
2644	break;
2645	}
2646	case 2:
2647	{
2648	png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
2649	png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
2650	int sshift, dshift;
2651	int s_start, s_end, s_inc;
2652	int jstop = png_pass_inc[pass];
2653	png_uint_32 i;
2654
2655	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2656	if (transformations & PNG_PACKSWAP)
2657	{
2658	sshift = (int)(((row_info->width + 3) & 0x03) << 1);
2659	dshift = (int)(((final_width + 3) & 0x03) << 1);
2660	s_start = 6;
2661	s_end = 0;
2662	s_inc = -2;
2663	}
2664	else
2665	#endif
2666	{
2667	sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
2668	dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
2669	s_start = 0;
2670	s_end = 6;
2671	s_inc = 2;
2672	}
2673
2674	for (i = 0; i < row_info->width; i++)
2675	{
2676	png_byte v;
2677	int j;
2678
2679	v = (png_byte)((*sp >> sshift) & 0x03);
2680	for (j = 0; j < jstop; j++)
2681	{
2682	*dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
2683	*dp \|= (png_byte)(v << dshift);
2684	if (dshift == s_end)
2685	{
2686	dshift = s_start;
2687	dp--;
2688	}
2689	else
2690	dshift += s_inc;
2691	}
2692	if (sshift == s_end)
2693	{
2694	sshift = s_start;
2695	sp--;
2696	}
2697	else
2698	sshift += s_inc;
2699	}
2700	break;
2701	}
2702	case 4:
2703	{
2704	png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
2705	png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
2706	int sshift, dshift;
2707	int s_start, s_end, s_inc;
2708	png_uint_32 i;
2709	int jstop = png_pass_inc[pass];
2710
2711	#if defined(PNG_READ_PACKSWAP_SUPPORTED)
2712	if (transformations & PNG_PACKSWAP)
2713	{
2714	sshift = (int)(((row_info->width + 1) & 0x01) << 2);
2715	dshift = (int)(((final_width + 1) & 0x01) << 2);
2716	s_start = 4;
2717	s_end = 0;
2718	s_inc = -4;
2719	}
2720	else
2721	#endif
2722	{
2723	sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
2724	dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
2725	s_start = 0;
2726	s_end = 4;
2727	s_inc = 4;
2728	}
2729
2730	for (i = 0; i < row_info->width; i++)
2731	{
2732	png_byte v = (png_byte)((*sp >> sshift) & 0xf);
2733	int j;
2734
2735	for (j = 0; j < jstop; j++)
2736	{
2737	*dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
2738	*dp \|= (png_byte)(v << dshift);
2739	if (dshift == s_end)
2740	{
2741	dshift = s_start;
2742	dp--;
2743	}
2744	else
2745	dshift += s_inc;
2746	}
2747	if (sshift == s_end)
2748	{
2749	sshift = s_start;
2750	sp--;
2751	}
2752	else
2753	sshift += s_inc;
2754	}
2755	break;
2756	}
2757	default:
2758	{
2759	png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
2760	png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
2761	png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
2762
2763	int jstop = png_pass_inc[pass];
2764	png_uint_32 i;
2765
2766	for (i = 0; i < row_info->width; i++)
2767	{
2768	png_byte v[8];
2769	int j;
2770
2771	png_memcpy(v, sp, pixel_bytes);
2772	for (j = 0; j < jstop; j++)
2773	{
2774	png_memcpy(dp, v, pixel_bytes);
2775	dp -= pixel_bytes;
2776	}
2777	sp -= pixel_bytes;
2778	}
2779	break;
2780	}
2781	}
2782	row_info->width = final_width;
2783	row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
2784	}
2785	#if !defined(PNG_READ_PACKSWAP_SUPPORTED)
2786	transformations = transformations; /* Silence compiler warning */
2787	#endif
2788	}
2789	#endif /* PNG_READ_INTERLACING_SUPPORTED */
2790
2791	void /* PRIVATE */
2792	png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
2793	png_bytep prev_row, int filter)
2794	{
2795	png_debug(1, "in png_read_filter_row");
2796	png_debug2(2, "row = %lu, filter = %d", png_ptr->row_number, filter);
2797	switch (filter)
2798	{
2799	case PNG_FILTER_VALUE_NONE:
2800	break;
2801	case PNG_FILTER_VALUE_SUB:
2802	{
2803	png_uint_32 i;
2804	png_uint_32 istop = row_info->rowbytes;
2805	png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
2806	png_bytep rp = row + bpp;
2807	png_bytep lp = row;
2808
2809	for (i = bpp; i < istop; i++)
2810	{
2811	rp = (png_byte)(((int)(rp) + (int)(*lp++)) & 0xff);
2812	rp++;
2813	}
2814	break;
2815	}
2816	case PNG_FILTER_VALUE_UP:
2817	{
2818	png_uint_32 i;
2819	png_uint_32 istop = row_info->rowbytes;
2820	png_bytep rp = row;
2821	png_bytep pp = prev_row;
2822
2823	for (i = 0; i < istop; i++)
2824	{
2825	rp = (png_byte)(((int)(rp) + (int)(*pp++)) & 0xff);
2826	rp++;
2827	}
2828	break;
2829	}
2830	case PNG_FILTER_VALUE_AVG:
2831	{
2832	png_uint_32 i;
2833	png_bytep rp = row;
2834	png_bytep pp = prev_row;
2835	png_bytep lp = row;
2836	png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
2837	png_uint_32 istop = row_info->rowbytes - bpp;
2838
2839	for (i = 0; i < bpp; i++)
2840	{
2841	rp = (png_byte)(((int)(rp) +
2842	((int)(*pp++) / 2 )) & 0xff);
2843	rp++;
2844	}
2845
2846	for (i = 0; i < istop; i++)
2847	{
2848	rp = (png_byte)(((int)(rp) +
2849	(int)(pp++ + lp++) / 2 ) & 0xff);
2850	rp++;
2851	}
2852	break;
2853	}
2854	case PNG_FILTER_VALUE_PAETH:
2855	{
2856	png_uint_32 i;
2857	png_bytep rp = row;
2858	png_bytep pp = prev_row;
2859	png_bytep lp = row;
2860	png_bytep cp = prev_row;
2861	png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
2862	png_uint_32 istop=row_info->rowbytes - bpp;
2863
2864	for (i = 0; i < bpp; i++)
2865	{
2866	rp = (png_byte)(((int)(rp) + (int)(*pp++)) & 0xff);
2867	rp++;
2868	}
2869
2870	for (i = 0; i < istop; i++) /* Use leftover rp,pp */
2871	{
2872	int a, b, c, pa, pb, pc, p;
2873
2874	a = *lp++;
2875	b = *pp++;
2876	c = *cp++;
2877
2878	p = b - c;
2879	pc = a - c;
2880
2881	#ifdef PNG_USE_ABS
2882	pa = abs(p);
2883	pb = abs(pc);
2884	pc = abs(p + pc);
2885	#else
2886	pa = p < 0 ? -p : p;
2887	pb = pc < 0 ? -pc : pc;
2888	pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2889	#endif
2890
2891	/*
2892	if (pa <= pb && pa <= pc)
2893	p = a;
2894	else if (pb <= pc)
2895	p = b;
2896	else
2897	p = c;
2898	*/
2899
2900	p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
2901
2902	rp = (png_byte)(((int)(rp) + p) & 0xff);
2903	rp++;
2904	}
2905	break;
2906	}
2907	default:
2908	png_warning(png_ptr, "Ignoring bad adaptive filter type");
2909	*row = 0;
2910	break;
2911	}
2912	}
2913
2914	#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
2915	void /* PRIVATE */
2916	png_read_finish_row(png_structp png_ptr)
2917	{
2918	#ifdef PNG_USE_LOCAL_ARRAYS
2919	#ifdef PNG_READ_INTERLACING_SUPPORTED
2920	/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2921
2922	/* Start of interlace block */
2923	PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
2924
2925	/* Offset to next interlace block */
2926	PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2927
2928	/* Start of interlace block in the y direction */
2929	PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
2930
2931	/* Offset to next interlace block in the y direction */
2932	PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
2933	#endif /* PNG_READ_INTERLACING_SUPPORTED */
2934	#endif
2935
2936	png_debug(1, "in png_read_finish_row");
2937	png_ptr->row_number++;
2938	if (png_ptr->row_number < png_ptr->num_rows)
2939	return;
2940
2941	#ifdef PNG_READ_INTERLACING_SUPPORTED
2942	if (png_ptr->interlaced)
2943	{
2944	png_ptr->row_number = 0;
2945	png_memset_check(png_ptr, png_ptr->prev_row, 0,
2946	png_ptr->rowbytes + 1);
2947	do
2948	{
2949	png_ptr->pass++;
2950	if (png_ptr->pass >= 7)
2951	break;
2952	png_ptr->iwidth = (png_ptr->width +
2953	png_pass_inc[png_ptr->pass] - 1 -
2954	png_pass_start[png_ptr->pass]) /
2955	png_pass_inc[png_ptr->pass];
2956
2957	png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
2958	png_ptr->iwidth) + 1;
2959
2960	if (!(png_ptr->transformations & PNG_INTERLACE))
2961	{
2962	png_ptr->num_rows = (png_ptr->height +
2963	png_pass_yinc[png_ptr->pass] - 1 -
2964	png_pass_ystart[png_ptr->pass]) /
2965	png_pass_yinc[png_ptr->pass];
2966	if (!(png_ptr->num_rows))
2967	continue;
2968	}
2969	else /* if (png_ptr->transformations & PNG_INTERLACE) */
2970	break;
2971	} while (png_ptr->iwidth == 0);
2972
2973	if (png_ptr->pass < 7)
2974	return;
2975	}
2976	#endif /* PNG_READ_INTERLACING_SUPPORTED */
2977
2978	if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
2979	{
2980	#ifdef PNG_USE_LOCAL_ARRAYS
2981	PNG_CONST PNG_IDAT;
2982	#endif
2983	char extra;
2984	int ret;
2985
2986	png_ptr->zstream.next_out = (Byte *)&extra;
2987	png_ptr->zstream.avail_out = (uInt)1;
2988	for (;;)
2989	{
2990	if (!(png_ptr->zstream.avail_in))
2991	{
2992	while (!png_ptr->idat_size)
2993	{
2994	png_byte chunk_length[4];
2995
2996	png_crc_finish(png_ptr, 0);
2997
2998	png_read_data(png_ptr, chunk_length, 4);
2999	png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
3000	png_reset_crc(png_ptr);
3001	png_crc_read(png_ptr, png_ptr->chunk_name, 4);
3002	if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
3003	png_error(png_ptr, "Not enough image data");
3004
3005	}
3006	png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
3007	png_ptr->zstream.next_in = png_ptr->zbuf;
3008	if (png_ptr->zbuf_size > png_ptr->idat_size)
3009	png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
3010	png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
3011	png_ptr->idat_size -= png_ptr->zstream.avail_in;
3012	}
3013	ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
3014	if (ret == Z_STREAM_END)
3015	{
3016	if (!(png_ptr->zstream.avail_out) \|\| png_ptr->zstream.avail_in \|\|
3017	png_ptr->idat_size)
3018	png_warning(png_ptr, "Extra compressed data");
3019	png_ptr->mode \|= PNG_AFTER_IDAT;
3020	png_ptr->flags \|= PNG_FLAG_ZLIB_FINISHED;
3021	break;
3022	}
3023	if (ret != Z_OK)
3024	png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
3025	"Decompression Error");
3026
3027	if (!(png_ptr->zstream.avail_out))
3028	{
3029	png_warning(png_ptr, "Extra compressed data.");
3030	png_ptr->mode \|= PNG_AFTER_IDAT;
3031	png_ptr->flags \|= PNG_FLAG_ZLIB_FINISHED;
3032	break;
3033	}
3034
3035	}
3036	png_ptr->zstream.avail_out = 0;
3037	}
3038
3039	if (png_ptr->idat_size \|\| png_ptr->zstream.avail_in)
3040	png_warning(png_ptr, "Extra compression data");
3041
3042	inflateReset(&png_ptr->zstream);
3043
3044	png_ptr->mode \|= PNG_AFTER_IDAT;
3045	}
3046	#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
3047
3048	void /* PRIVATE */
3049	png_read_start_row(png_structp png_ptr)
3050	{
3051	#ifdef PNG_USE_LOCAL_ARRAYS
3052	#ifdef PNG_READ_INTERLACING_SUPPORTED
3053	/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
3054
3055	/* Start of interlace block */
3056	PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
3057
3058	/* Offset to next interlace block */
3059	PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
3060
3061	/* Start of interlace block in the y direction */
3062	PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
3063
3064	/* Offset to next interlace block in the y direction */
3065	PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
3066	#endif
3067	#endif
3068
3069	int max_pixel_depth;
3070	png_size_t row_bytes;
3071
3072	png_debug(1, "in png_read_start_row");
3073	png_ptr->zstream.avail_in = 0;
3074	png_init_read_transformations(png_ptr);
3075	#ifdef PNG_READ_INTERLACING_SUPPORTED
3076	if (png_ptr->interlaced)
3077	{
3078	if (!(png_ptr->transformations & PNG_INTERLACE))
3079	png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
3080	png_pass_ystart[0]) / png_pass_yinc[0];
3081	else
3082	png_ptr->num_rows = png_ptr->height;
3083
3084	png_ptr->iwidth = (png_ptr->width +
3085	png_pass_inc[png_ptr->pass] - 1 -
3086	png_pass_start[png_ptr->pass]) /
3087	png_pass_inc[png_ptr->pass];
3088
3089	png_ptr->irowbytes =
3090	PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1;
3091	}
3092	else
3093	#endif /* PNG_READ_INTERLACING_SUPPORTED */
3094	{
3095	png_ptr->num_rows = png_ptr->height;
3096	png_ptr->iwidth = png_ptr->width;
3097	png_ptr->irowbytes = png_ptr->rowbytes + 1;
3098	}
3099	max_pixel_depth = png_ptr->pixel_depth;
3100
3101	#if defined(PNG_READ_PACK_SUPPORTED)
3102	if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
3103	max_pixel_depth = 8;
3104	#endif
3105
3106	#if defined(PNG_READ_EXPAND_SUPPORTED)
3107	if (png_ptr->transformations & PNG_EXPAND)
3108	{
3109	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
3110	{
3111	if (png_ptr->num_trans)
3112	max_pixel_depth = 32;
3113	else
3114	max_pixel_depth = 24;
3115	}
3116	else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
3117	{
3118	if (max_pixel_depth < 8)
3119	max_pixel_depth = 8;
3120	if (png_ptr->num_trans)
3121	max_pixel_depth *= 2;
3122	}
3123	else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
3124	{
3125	if (png_ptr->num_trans)
3126	{
3127	max_pixel_depth *= 4;
3128	max_pixel_depth /= 3;
3129	}
3130	}
3131	}
3132	#endif
3133
3134	#if defined(PNG_READ_FILLER_SUPPORTED)
3135	if (png_ptr->transformations & (PNG_FILLER))
3136	{
3137	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
3138	max_pixel_depth = 32;
3139	else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
3140	{
3141	if (max_pixel_depth <= 8)
3142	max_pixel_depth = 16;
3143	else
3144	max_pixel_depth = 32;
3145	}
3146	else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
3147	{
3148	if (max_pixel_depth <= 32)
3149	max_pixel_depth = 32;
3150	else
3151	max_pixel_depth = 64;
3152	}
3153	}
3154	#endif
3155
3156	#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3157	if (png_ptr->transformations & PNG_GRAY_TO_RGB)
3158	{
3159	if (
3160	#if defined(PNG_READ_EXPAND_SUPPORTED)
3161	(png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) \|\|
3162	#endif
3163	#if defined(PNG_READ_FILLER_SUPPORTED)
3164	(png_ptr->transformations & (PNG_FILLER)) \|\|
3165	#endif
3166	png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
3167	{
3168	if (max_pixel_depth <= 16)
3169	max_pixel_depth = 32;
3170	else
3171	max_pixel_depth = 64;
3172	}
3173	else
3174	{
3175	if (max_pixel_depth <= 8)
3176	{
3177	if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
3178	max_pixel_depth = 32;
3179	else
3180	max_pixel_depth = 24;
3181	}
3182	else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
3183	max_pixel_depth = 64;
3184	else
3185	max_pixel_depth = 48;
3186	}
3187	}
3188	#endif
3189
3190	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
3191	defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
3192	if (png_ptr->transformations & PNG_USER_TRANSFORM)
3193	{
3194	int user_pixel_depth = png_ptr->user_transform_depth*
3195	png_ptr->user_transform_channels;
3196	if (user_pixel_depth > max_pixel_depth)
3197	max_pixel_depth=user_pixel_depth;
3198	}
3199	#endif
3200
3201	/* Align the width on the next larger 8 pixels. Mainly used
3202	* for interlacing
3203	*/
3204	row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
3205	/* Calculate the maximum bytes needed, adding a byte and a pixel
3206	* for safety's sake
3207	*/
3208	row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
3209	1 + ((max_pixel_depth + 7) >> 3);
3210	#ifdef PNG_MAX_MALLOC_64K
3211	if (row_bytes > (png_uint_32)65536L)
3212	png_error(png_ptr, "This image requires a row greater than 64KB");
3213	#endif
3214
3215	if (row_bytes + 64 > png_ptr->old_big_row_buf_size)
3216	{
3217	png_free(png_ptr, png_ptr->big_row_buf);
3218	png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 64);
3219	if (png_ptr->interlaced)
3220	png_memset(png_ptr->big_row_buf, 0, row_bytes + 64);
3221	png_ptr->row_buf = png_ptr->big_row_buf + 32;
3222	png_ptr->old_big_row_buf_size = row_bytes + 64;
3223	}
3224
3225	#ifdef PNG_MAX_MALLOC_64K
3226	if ((png_uint_32)row_bytes + 1 > (png_uint_32)65536L)
3227	png_error(png_ptr, "This image requires a row greater than 64KB");
3228	#endif
3229	if ((png_uint_32)row_bytes > (png_uint_32)(PNG_SIZE_MAX - 1))
3230	png_error(png_ptr, "Row has too many bytes to allocate in memory.");
3231
3232	if (row_bytes + 1 > png_ptr->old_prev_row_size)
3233	{
3234	png_free(png_ptr, png_ptr->prev_row);
3235	png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
3236	row_bytes + 1));
3237	png_memset_check(png_ptr, png_ptr->prev_row, 0, row_bytes + 1);
3238	png_ptr->old_prev_row_size = row_bytes + 1;
3239	}
3240
3241	png_ptr->rowbytes = row_bytes;
3242
3243	png_debug1(3, "width = %lu,", png_ptr->width);
3244	png_debug1(3, "height = %lu,", png_ptr->height);
3245	png_debug1(3, "iwidth = %lu,", png_ptr->iwidth);
3246	png_debug1(3, "num_rows = %lu,", png_ptr->num_rows);
3247	png_debug1(3, "rowbytes = %lu,", png_ptr->rowbytes);
3248	png_debug1(3, "irowbytes = %lu", png_ptr->irowbytes);
3249
3250	png_ptr->flags \|= PNG_FLAG_ROW_INIT;
3251	}
3252	#endif /* PNG_READ_SUPPORTED */

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