diff options
Diffstat (limited to 'third_party/libpng16/png.c')
| -rw-r--r-- | third_party/libpng16/png.c | 627 |
1 files changed, 354 insertions, 273 deletions
diff --git a/third_party/libpng16/png.c b/third_party/libpng16/png.c index 01d8d9bae6..22dcef260e 100644 --- a/third_party/libpng16/png.c +++ b/third_party/libpng16/png.c @@ -1,8 +1,8 @@ /* png.c - location for general purpose libpng functions * - * Last changed in libpng 1.6.19 [November 12, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * Last changed in libpng 1.6.33 [September 28, 2017] + * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -14,7 +14,27 @@ #include "pngpriv.h" /* Generate a compiler error if there is an old png.h in the search path. */ -typedef png_libpng_version_1_6_22 Your_png_h_is_not_version_1_6_22; +typedef png_libpng_version_1_6_34 Your_png_h_is_not_version_1_6_34; + +#ifdef __GNUC__ +/* The version tests may need to be added to, but the problem warning has + * consistently been fixed in GCC versions which obtain wide-spread release. + * The problem is that many versions of GCC rearrange comparison expressions in + * the optimizer in such a way that the results of the comparison will change + * if signed integer overflow occurs. Such comparisons are not permitted in + * ANSI C90, however GCC isn't clever enough to work out that that do not occur + * below in png_ascii_from_fp and png_muldiv, so it produces a warning with + * -Wextra. Unfortunately this is highly dependent on the optimizer and the + * machine architecture so the warning comes and goes unpredictably and is + * impossible to "fix", even were that a good idea. + */ +#if __GNUC__ == 7 && __GNUC_MINOR__ == 1 +#define GCC_STRICT_OVERFLOW 1 +#endif /* GNU 7.1.x */ +#endif /* GNU */ +#ifndef GCC_STRICT_OVERFLOW +#define GCC_STRICT_OVERFLOW 0 +#endif /* Tells libpng that we have already handled the first "num_bytes" bytes * of the PNG file signature. If the PNG data is embedded into another @@ -85,7 +105,7 @@ png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED) if (items >= (~(png_alloc_size_t)0)/size) { png_warning (png_voidcast(png_structrp, png_ptr), - "Potential overflow in png_zalloc()"); + "Potential overflow in png_zalloc()"); return NULL; } @@ -172,10 +192,10 @@ png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length) int png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver) { - /* Libpng versions 1.0.0 and later are binary compatible if the version - * string matches through the second '.'; we must recompile any - * applications that use any older library version. - */ + /* Libpng versions 1.0.0 and later are binary compatible if the version + * string matches through the second '.'; we must recompile any + * applications that use any older library version. + */ if (user_png_ver != NULL) { @@ -297,7 +317,7 @@ png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr, if (png_user_version_check(&create_struct, user_png_ver) != 0) { png_structrp png_ptr = png_voidcast(png_structrp, - png_malloc_warn(&create_struct, (sizeof *png_ptr))); + png_malloc_warn(&create_struct, (sizeof *png_ptr))); if (png_ptr != NULL) { @@ -346,7 +366,7 @@ png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED) * has always been done in 'example.c'. */ info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr, - (sizeof *info_ptr))); + (sizeof *info_ptr))); if (info_ptr != NULL) memset(info_ptr, 0, (sizeof *info_ptr)); @@ -402,7 +422,7 @@ png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr) */ PNG_FUNCTION(void,PNGAPI png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size), - PNG_DEPRECATED) + PNG_DEPRECATED) { png_inforp info_ptr = *ptr_ptr; @@ -417,7 +437,7 @@ png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size), /* The following line is why this API should not be used: */ free(info_ptr); info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL, - (sizeof *info_ptr))); + (sizeof *info_ptr))); if (info_ptr == NULL) return; *ptr_ptr = info_ptr; @@ -430,7 +450,7 @@ png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size), /* The following API is not called internally */ void PNGAPI png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, - int freer, png_uint_32 mask) + int freer, png_uint_32 mask) { png_debug(1, "in png_data_freer"); @@ -449,7 +469,7 @@ png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, void PNGAPI png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, - int num) + int num) { png_debug(1, "in png_free_data"); @@ -458,7 +478,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, #ifdef PNG_TEXT_SUPPORTED /* Free text item num or (if num == -1) all text items */ - if (info_ptr->text != 0 && + if (info_ptr->text != NULL && ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0) { if (num != -1) @@ -477,6 +497,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, png_free(png_ptr, info_ptr->text); info_ptr->text = NULL; info_ptr->num_text = 0; + info_ptr->max_text = 0; } } #endif @@ -541,7 +562,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, #ifdef PNG_sPLT_SUPPORTED /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ - if (info_ptr->splt_palettes != 0 && + if (info_ptr->splt_palettes != NULL && ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0) { if (num != -1) @@ -571,7 +592,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, #endif #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED - if (info_ptr->unknown_chunks != 0 && + if (info_ptr->unknown_chunks != NULL && ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0) { if (num != -1) @@ -594,6 +615,26 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, } #endif +#ifdef PNG_eXIf_SUPPORTED + /* Free any eXIf entry */ + if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0) + { +# ifdef PNG_READ_eXIf_SUPPORTED + if (info_ptr->eXIf_buf) + { + png_free(png_ptr, info_ptr->eXIf_buf); + info_ptr->eXIf_buf = NULL; + } +# endif + if (info_ptr->exif) + { + png_free(png_ptr, info_ptr->exif); + info_ptr->exif = NULL; + } + info_ptr->valid &= ~PNG_INFO_eXIf; + } +#endif + #ifdef PNG_hIST_SUPPORTED /* Free any hIST entry */ if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0) @@ -617,7 +658,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, /* Free any image bits attached to the info structure */ if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0) { - if (info_ptr->row_pointers != 0) + if (info_ptr->row_pointers != NULL) { png_uint_32 row; for (row = 0; row < info_ptr->height; row++) @@ -684,7 +725,7 @@ png_init_io(png_structrp png_ptr, png_FILE_p fp) void PNGAPI png_save_int_32(png_bytep buf, png_int_32 i) { - png_save_uint_32(buf, i); + png_save_uint_32(buf, (png_uint_32)i); } # endif @@ -775,15 +816,15 @@ png_get_copyright(png_const_structrp png_ptr) #else # ifdef __STDC__ return PNG_STRING_NEWLINE \ - "libpng version 1.6.22 - May 26, 2016" PNG_STRING_NEWLINE \ - "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \ + "libpng version 1.6.34 - September 29, 2017" PNG_STRING_NEWLINE \ + "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \ PNG_STRING_NEWLINE \ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ PNG_STRING_NEWLINE; # else - return "libpng version 1.6.22 - May 26, 2016\ - Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\ + return "libpng version 1.6.34 - September 29, 2017\ + Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\ Copyright (c) 1996-1997 Andreas Dilger\ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."; # endif @@ -1033,7 +1074,7 @@ png_zstream_error(png_structrp png_ptr, int ret) #ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */ static int png_colorspace_check_gamma(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_fixed_point gAMA, int from) + png_colorspacerp colorspace, png_fixed_point gAMA, int from) /* This is called to check a new gamma value against an existing one. The * routine returns false if the new gamma value should not be written. * @@ -1047,7 +1088,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr, png_fixed_point gtest; if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && - (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 || + (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 || png_gamma_significant(gtest) != 0)) { /* Either this is an sRGB image, in which case the calculated gamma @@ -1059,7 +1100,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr, if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2) { png_chunk_report(png_ptr, "gamma value does not match sRGB", - PNG_CHUNK_ERROR); + PNG_CHUNK_ERROR); /* Do not overwrite an sRGB value */ return from == 2; } @@ -1067,7 +1108,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr, else /* sRGB tag not involved */ { png_chunk_report(png_ptr, "gamma value does not match libpng estimate", - PNG_CHUNK_WARNING); + PNG_CHUNK_WARNING); return from == 1; } } @@ -1077,7 +1118,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr, void /* PRIVATE */ png_colorspace_set_gamma(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_fixed_point gAMA) + png_colorspacerp colorspace, png_fixed_point gAMA) { /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't * occur. Since the fixed point representation is asymetrical it is @@ -1635,8 +1676,8 @@ static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */ static int png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ, - int preferred) + png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ, + int preferred) { if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) return 0; @@ -1683,7 +1724,7 @@ png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr, int /* PRIVATE */ png_colorspace_set_chromaticities(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_xy *xy, int preferred) + png_colorspacerp colorspace, const png_xy *xy, int preferred) { /* We must check the end points to ensure they are reasonable - in the past * color management systems have crashed as a result of getting bogus @@ -1697,7 +1738,7 @@ png_colorspace_set_chromaticities(png_const_structrp png_ptr, { case 0: /* success */ return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ, - preferred); + preferred); case 1: /* We can't invert the chromaticities so we can't produce value XYZ @@ -1720,7 +1761,7 @@ png_colorspace_set_chromaticities(png_const_structrp png_ptr, int /* PRIVATE */ png_colorspace_set_endpoints(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred) + png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred) { png_XYZ XYZ = *XYZ_in; png_xy xy; @@ -1729,7 +1770,7 @@ png_colorspace_set_endpoints(png_const_structrp png_ptr, { case 0: return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ, - preferred); + preferred); case 1: /* End points are invalid. */ @@ -1786,7 +1827,7 @@ is_ICC_signature(png_alloc_size_t it) static int png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_alloc_size_t value, png_const_charp reason) + png_const_charp name, png_alloc_size_t value, png_const_charp reason) { size_t pos; char message[196]; /* see below for calculation */ @@ -1811,8 +1852,8 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/ pos = png_safecat(message, (sizeof message), pos, - png_format_number(number, number+(sizeof number), - PNG_NUMBER_FORMAT_x, value)); + png_format_number(number, number+(sizeof number), + PNG_NUMBER_FORMAT_x, value)); pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/ } # endif @@ -1826,7 +1867,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, * application errors the PNG won't be written.) */ png_chunk_report(png_ptr, message, - (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR); + (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR); return 0; } @@ -1835,7 +1876,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, #ifdef PNG_sRGB_SUPPORTED int /* PRIVATE */ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, - int intent) + int intent) { /* sRGB sets known gamma, end points and (from the chunk) intent. */ /* IMPORTANT: these are not necessarily the values found in an ICC profile @@ -1872,12 +1913,12 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, */ if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST) return png_icc_profile_error(png_ptr, colorspace, "sRGB", - (unsigned)intent, "invalid sRGB rendering intent"); + (png_alloc_size_t)intent, "invalid sRGB rendering intent"); if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 && - colorspace->rendering_intent != intent) + colorspace->rendering_intent != intent) return png_icc_profile_error(png_ptr, colorspace, "sRGB", - (unsigned)intent, "inconsistent rendering intents"); + (png_alloc_size_t)intent, "inconsistent rendering intents"); if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0) { @@ -1889,8 +1930,8 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, * warn but overwrite the value with the correct one. */ if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 && - !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy, - 100)) + !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy, + 100)) png_chunk_report(png_ptr, "cHRM chunk does not match sRGB", PNG_CHUNK_ERROR); @@ -1898,7 +1939,7 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, * returns true when the 'from' argument corresponds to sRGB (2). */ (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE, - 2/*from sRGB*/); + 2/*from sRGB*/); /* intent: bugs in GCC force 'int' to be used as the parameter type. */ colorspace->rendering_intent = (png_uint_16)intent; @@ -1933,12 +1974,11 @@ static const png_byte D50_nCIEXYZ[12] = static int /* bool */ icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length) + png_const_charp name, png_uint_32 profile_length) { if (profile_length < 132) return png_icc_profile_error(png_ptr, colorspace, name, profile_length, - "too short"); - + "too short"); return 1; } @@ -1978,8 +2018,8 @@ png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, int /* PRIVATE */ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, - png_const_bytep profile/* first 132 bytes only */, int color_type) + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile/* first 132 bytes only */, int color_type) { png_uint_32 temp; @@ -1991,18 +2031,18 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, temp = png_get_uint_32(profile); if (temp != profile_length) return png_icc_profile_error(png_ptr, colorspace, name, temp, - "length does not match profile"); + "length does not match profile"); temp = (png_uint_32) (*(profile+8)); if (temp > 3 && (profile_length & 3)) return png_icc_profile_error(png_ptr, colorspace, name, profile_length, - "invalid length"); + "invalid length"); temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */ if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */ profile_length < 132+12*temp) /* truncated tag table */ return png_icc_profile_error(png_ptr, colorspace, name, temp, - "tag count too large"); + "tag count too large"); /* The 'intent' must be valid or we can't store it, ICC limits the intent to * 16 bits. @@ -2010,14 +2050,14 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, temp = png_get_uint_32(profile+64); if (temp >= 0xffff) /* The ICC limit */ return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid rendering intent"); + "invalid rendering intent"); /* This is just a warning because the profile may be valid in future * versions. */ if (temp >= PNG_sRGB_INTENT_LAST) (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "intent outside defined range"); + "intent outside defined range"); /* At this point the tag table can't be checked because it hasn't necessarily * been loaded; however, various header fields can be checked. These checks @@ -2034,7 +2074,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, temp = png_get_uint_32(profile+36); /* signature 'ascp' */ if (temp != 0x61637370) return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid signature"); + "invalid signature"); /* Currently the PCS illuminant/adopted white point (the computational * white point) are required to be D50, @@ -2045,7 +2085,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, */ if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0) (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/, - "PCS illuminant is not D50"); + "PCS illuminant is not D50"); /* The PNG spec requires this: * "If the iCCP chunk is present, the image samples conform to the colour @@ -2073,18 +2113,18 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, case 0x52474220: /* 'RGB ' */ if ((color_type & PNG_COLOR_MASK_COLOR) == 0) return png_icc_profile_error(png_ptr, colorspace, name, temp, - "RGB color space not permitted on grayscale PNG"); + "RGB color space not permitted on grayscale PNG"); break; case 0x47524159: /* 'GRAY' */ if ((color_type & PNG_COLOR_MASK_COLOR) != 0) return png_icc_profile_error(png_ptr, colorspace, name, temp, - "Gray color space not permitted on RGB PNG"); + "Gray color space not permitted on RGB PNG"); break; default: return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid ICC profile color space"); + "invalid ICC profile color space"); } /* It is up to the application to check that the profile class matches the @@ -2109,7 +2149,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, case 0x61627374: /* 'abst' */ /* May not be embedded in an image */ return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid embedded Abstract ICC profile"); + "invalid embedded Abstract ICC profile"); case 0x6c696e6b: /* 'link' */ /* DeviceLink profiles cannot be interpreted in a non-device specific @@ -2119,7 +2159,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, * PNG. */ return png_icc_profile_error(png_ptr, colorspace, name, temp, - "unexpected DeviceLink ICC profile class"); + "unexpected DeviceLink ICC profile class"); case 0x6e6d636c: /* 'nmcl' */ /* A NamedColor profile is also device specific, however it doesn't @@ -2127,7 +2167,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, * certainly it will fail the tests below. */ (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "unexpected NamedColor ICC profile class"); + "unexpected NamedColor ICC profile class"); break; default: @@ -2137,7 +2177,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, * understood profiles. */ (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "unrecognized ICC profile class"); + "unrecognized ICC profile class"); break; } @@ -2153,7 +2193,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, default: return png_icc_profile_error(png_ptr, colorspace, name, temp, - "unexpected ICC PCS encoding"); + "unexpected ICC PCS encoding"); } return 1; @@ -2161,8 +2201,8 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, int /* PRIVATE */ png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, - png_const_bytep profile /* header plus whole tag table */) + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile /* header plus whole tag table */) { png_uint_32 tag_count = png_get_uint_32(profile+128); png_uint_32 itag; @@ -2183,22 +2223,23 @@ png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace, * being in range. All defined tag types have an 8 byte header - a 4 byte * type signature then 0. */ + + /* This is a hard error; potentially it can cause read outside the + * profile. + */ + if (tag_start > profile_length || tag_length > profile_length - tag_start) + return png_icc_profile_error(png_ptr, colorspace, name, tag_id, + "ICC profile tag outside profile"); + if ((tag_start & 3) != 0) { - /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is + /* CNHP730S.icc shipped with Microsoft Windows 64 violates this; it is * only a warning here because libpng does not care about the * alignment. */ (void)png_icc_profile_error(png_ptr, NULL, name, tag_id, - "ICC profile tag start not a multiple of 4"); + "ICC profile tag start not a multiple of 4"); } - - /* This is a hard error; potentially it can cause read outside the - * profile. - */ - if (tag_start > profile_length || tag_length > profile_length - tag_start) - return png_icc_profile_error(png_ptr, colorspace, name, tag_id, - "ICC profile tag outside profile"); } return 1; /* success, maybe with warnings */ @@ -2226,22 +2267,22 @@ static const struct */ /* adler32, crc32, MD5[4], intent, date, length, file-name */ PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9, - PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0, - "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc") + PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0, + "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc") /* ICC sRGB v2 perceptual no black-compensation: */ PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21, - PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0, - "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc") + PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0, + "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc") PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae, - PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0, - "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc") + PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0, + "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc") /* ICC sRGB v4 perceptual */ PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812, - PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0, - "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") + PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0, + "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") /* The following profiles have no known MD5 checksum. If there is a match * on the (empty) MD5 the other fields are used to attempt a match and @@ -2249,8 +2290,8 @@ static const struct * which suggests that they were also made by Hewlett Packard. */ PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0, - "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc") + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0, + "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc") /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not * match the D50 PCS illuminant in the header (it is in fact the D65 values, @@ -2260,17 +2301,17 @@ static const struct * chromaticAdaptationTag. */ PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/, - "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual") + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual") PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/, - "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative") + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative") }; static int png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, - png_const_bytep profile, uLong adler) + png_const_bytep profile, uLong adler) { /* The quick check is to verify just the MD5 signature and trust the * rest of the data. Because the profile has already been verified for @@ -2354,7 +2395,7 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, * which is made irrelevant by this error. */ png_chunk_report(png_ptr, "known incorrect sRGB profile", - PNG_CHUNK_ERROR); + PNG_CHUNK_ERROR); } /* Warn that this being done; this isn't even an error since @@ -2364,8 +2405,8 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, else if (png_sRGB_checks[i].have_md5 == 0) { png_chunk_report(png_ptr, - "out-of-date sRGB profile with no signature", - PNG_CHUNK_WARNING); + "out-of-date sRGB profile with no signature", + PNG_CHUNK_WARNING); } return 1+png_sRGB_checks[i].is_broken; @@ -2388,38 +2429,36 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, return 0; /* no match */ } -#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */ void /* PRIVATE */ png_icc_set_sRGB(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_bytep profile, uLong adler) + png_colorspacerp colorspace, png_const_bytep profile, uLong adler) { /* Is this profile one of the known ICC sRGB profiles? If it is, just set * the sRGB information. */ -#if PNG_sRGB_PROFILE_CHECKS >= 0 if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0) -#endif (void)png_colorspace_set_sRGB(png_ptr, colorspace, (int)/*already checked*/png_get_uint_32(profile+64)); } +#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */ #endif /* sRGB */ int /* PRIVATE */ png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, png_const_bytep profile, - int color_type) + png_const_charp name, png_uint_32 profile_length, png_const_bytep profile, + int color_type) { if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) return 0; if (icc_check_length(png_ptr, colorspace, name, profile_length) != 0 && png_icc_check_header(png_ptr, colorspace, name, profile_length, profile, - color_type) != 0 && + color_type) != 0 && png_icc_check_tag_table(png_ptr, colorspace, name, profile_length, - profile) != 0) + profile) != 0) { -# ifdef PNG_sRGB_SUPPORTED +# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0 /* If no sRGB support, don't try storing sRGB information */ png_icc_set_sRGB(png_ptr, colorspace, profile, 0); # endif @@ -2478,7 +2517,7 @@ png_colorspace_set_rgb_coefficients(png_structrp png_ptr) /* Check for an internal error. */ if (r+g+b != 32768) png_error(png_ptr, - "internal error handling cHRM coefficients"); + "internal error handling cHRM coefficients"); else { @@ -2505,7 +2544,7 @@ png_colorspace_set_rgb_coefficients(png_structrp png_ptr) static int /* PRIVATE */ png_gt(size_t a, size_t b) { - return a > b; + return a > b; } #else # define png_gt(a,b) ((a) > (b)) @@ -2513,9 +2552,9 @@ png_gt(size_t a, size_t b) void /* PRIVATE */ png_check_IHDR(png_const_structrp png_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, - int color_type, int interlace_type, int compression_type, - int filter_type) + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) { int error = 0; @@ -2532,7 +2571,7 @@ png_check_IHDR(png_const_structrp png_ptr, error = 1; } - if (png_gt(((width + 7) & (~7)), + if (png_gt(((width + 7) & (~7U)), ((PNG_SIZE_MAX - 48 /* big_row_buf hack */ - 1) /* filter byte */ @@ -2678,7 +2717,7 @@ png_check_IHDR(png_const_structrp png_ptr, int /* PRIVATE */ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, - png_size_tp whereami) + png_size_tp whereami) { int state = *statep; png_size_t i = *whereami; @@ -2834,7 +2873,7 @@ png_pow10(int power) if (power < 0) { if (power < DBL_MIN_10_EXP) return 0; - recip = 1, power = -power; + recip = 1; power = -power; } if (power > 0) @@ -2859,6 +2898,14 @@ png_pow10(int power) /* Function to format a floating point value in ASCII with a given * precision. */ +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic push +/* The problem arises below with exp_b10, which can never overflow because it + * comes, originally, from frexp and is therefore limited to a range which is + * typically +/-710 (log2(DBL_MAX)/log2(DBL_MIN)). + */ +#pragma GCC diagnostic warning "-Wstrict-overflow=2" +#endif /* GCC_STRICT_OVERFLOW */ void /* PRIVATE */ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, double fp, unsigned int precision) @@ -2912,7 +2959,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, double test = png_pow10(exp_b10+1); if (test <= DBL_MAX) - ++exp_b10, base = test; + { + ++exp_b10; base = test; + } else break; @@ -2926,7 +2975,10 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, * test on DBL_MAX above. */ fp /= base; - while (fp >= 1) fp /= 10, ++exp_b10; + while (fp >= 1) + { + fp /= 10; ++exp_b10; + } /* Because of the code above fp may, at this point, be * less than .1, this is ok because the code below can @@ -2943,7 +2995,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, */ if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */ { - czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */ + czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */ exp_b10 = 0; /* Dot added below before first output. */ } else @@ -2977,7 +3029,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, /* Rounding up to 10, handle that here. */ if (czero > 0) { - --czero, d = 1; + --czero; d = 1; if (cdigits == 0) --clead; } else @@ -2991,7 +3043,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, else if (ch == 46) { - ch = *--ascii, ++size; + ch = *--ascii; ++size; /* Advance exp_b10 to '1', so that the * decimal point happens after the * previous digit. @@ -3018,7 +3070,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, int ch = *--ascii; if (ch == 46) - ++size, exp_b10 = 1; + { + ++size; exp_b10 = 1; + } /* Else lost a leading zero, so 'exp_b10' is * still ok at (-1) @@ -3054,21 +3108,26 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, */ if (exp_b10 != (-1)) { - if (exp_b10 == 0) *ascii++ = 46, --size; + if (exp_b10 == 0) + { + *ascii++ = 46; --size; + } /* PLUS 1: TOTAL 4 */ --exp_b10; } - *ascii++ = 48, --czero; + *ascii++ = 48; --czero; } if (exp_b10 != (-1)) { if (exp_b10 == 0) - *ascii++ = 46, --size; /* counted above */ + { + *ascii++ = 46; --size; /* counted above */ + } --exp_b10; } - *ascii++ = (char)(48 + (int)d), ++cdigits; + *ascii++ = (char)(48 + (int)d); ++cdigits; } } while (cdigits+czero < precision+clead && fp > DBL_MIN); @@ -3077,7 +3136,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, /* Check for an exponent, if we don't need one we are * done and just need to terminate the string. At - * this point exp_b10==(-1) is effectively if flag - it got + * this point exp_b10==(-1) is effectively a flag - it got * to '-1' because of the decrement after outputting * the decimal point above (the exponent required is * *not* -1!) @@ -3091,7 +3150,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, * zeros were *not* output, so this doesn't increase * the output count. */ - while (--exp_b10 >= 0) *ascii++ = 48; + while (exp_b10-- > 0) *ascii++ = 48; *ascii = 0; @@ -3109,7 +3168,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, */ size -= cdigits; - *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */ + *ascii++ = 69; --size; /* 'E': PLUS 1 TOTAL 2+precision */ /* The following use of an unsigned temporary avoids ambiguities in * the signed arithmetic on exp_b10 and permits GCC at least to do @@ -3120,12 +3179,12 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, if (exp_b10 < 0) { - *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ - uexp_b10 = -exp_b10; + *ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */ + uexp_b10 = 0U-exp_b10; } else - uexp_b10 = exp_b10; + uexp_b10 = 0U+exp_b10; cdigits = 0; @@ -3168,6 +3227,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, /* Here on buffer too small. */ png_error(png_ptr, "ASCII conversion buffer too small"); } +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic pop +#endif /* GCC_STRICT_OVERFLOW */ # endif /* FLOATING_POINT */ @@ -3187,9 +3249,11 @@ png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii, /* Avoid overflow here on the minimum integer. */ if (fp < 0) - *ascii++ = 45, num = -fp; + { + *ascii++ = 45; num = (png_uint_32)(-fp); + } else - num = fp; + num = (png_uint_32)fp; if (num <= 0x80000000) /* else overflowed */ { @@ -3225,7 +3289,10 @@ png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii, * then ndigits digits to first: */ i = 5; - while (ndigits < i) *ascii++ = 48, --i; + while (ndigits < i) + { + *ascii++ = 48; --i; + } while (ndigits >= first) *ascii++ = digits[--ndigits]; /* Don't output the trailing zeros! */ } @@ -3276,6 +3343,15 @@ png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text) * the nearest .00001). Overflow and divide by zero are signalled in * the result, a boolean - true on success, false on overflow. */ +#if GCC_STRICT_OVERFLOW /* from above */ +/* It is not obvious which comparison below gets optimized in such a way that + * signed overflow would change the result; looking through the code does not + * reveal any tests which have the form GCC complains about, so presumably the + * optimizer is moving an add or subtract into the 'if' somewhere. + */ +#pragma GCC diagnostic push +#pragma GCC diagnostic warning "-Wstrict-overflow=2" +#endif /* GCC_STRICT_OVERFLOW */ int png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, png_int_32 divisor) @@ -3390,6 +3466,9 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, return 0; } +#if GCC_STRICT_OVERFLOW +#pragma GCC diagnostic pop +#endif /* GCC_STRICT_OVERFLOW */ #endif /* READ_GAMMA || INCH_CONVERSIONS */ #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) @@ -3683,7 +3762,7 @@ png_log16bit(png_uint_32 x) * of getting this accuracy in practice. * * To deal with this the following exp() function works out the exponent of the - * frational part of the logarithm by using an accurate 32-bit value from the + * fractional part of the logarithm by using an accurate 32-bit value from the * top four fractional bits then multiplying in the remaining bits. */ static const png_uint_32 @@ -3841,25 +3920,25 @@ png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) { if (value > 0 && value < 65535) { -# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - /* The same (unsigned int)->(double) constraints apply here as above, - * however in this case the (unsigned int) to (int) conversion can - * overflow on an ANSI-C90 compliant system so the cast needs to ensure - * that this is not possible. - */ - double r = floor(65535*pow((png_int_32)value/65535., - gamma_val*.00001)+.5); - return (png_uint_16)r; -# else - png_int_32 lg2 = png_log16bit(value); - png_fixed_point res; - - if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) - return png_exp16bit(res); - - /* Overflow. */ - value = 0; -# endif +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* The same (unsigned int)->(double) constraints apply here as above, + * however in this case the (unsigned int) to (int) conversion can + * overflow on an ANSI-C90 compliant system so the cast needs to ensure + * that this is not possible. + */ + double r = floor(65535*pow((png_int_32)value/65535., + gamma_val*.00001)+.5); + return (png_uint_16)r; +# else + png_int_32 lg2 = png_log16bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) + return png_exp16bit(res); + + /* Overflow. */ + value = 0; +# endif } return (png_uint_16)value; @@ -3898,7 +3977,7 @@ png_gamma_correct(png_structrp png_ptr, unsigned int value, */ static void png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, - PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) { /* Various values derived from 'shift': */ PNG_CONST unsigned int num = 1U << (8U - shift); @@ -3975,7 +4054,7 @@ png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, */ static void png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable, - PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) { PNG_CONST unsigned int num = 1U << (8U - shift); PNG_CONST unsigned int max = (1U << (16U - shift))-1U; @@ -4043,7 +4122,7 @@ png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable, */ static void png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable, - PNG_CONST png_fixed_point gamma_val) + PNG_CONST png_fixed_point gamma_val) { unsigned int i; png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256); @@ -4123,131 +4202,133 @@ png_destroy_gamma_table(png_structrp png_ptr) void /* PRIVATE */ png_build_gamma_table(png_structrp png_ptr, int bit_depth) { - png_debug(1, "in png_build_gamma_table"); - - /* Remove any existing table; this copes with multiple calls to - * png_read_update_info. The warning is because building the gamma tables - * multiple times is a performance hit - it's harmless but the ability to call - * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible - * to warn if the app introduces such a hit. - */ - if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) - { - png_warning(png_ptr, "gamma table being rebuilt"); - png_destroy_gamma_table(png_ptr); - } - - if (bit_depth <= 8) - { - png_build_8bit_table(png_ptr, &png_ptr->gamma_table, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); + png_debug(1, "in png_build_gamma_table"); + + /* Remove any existing table; this copes with multiple calls to + * png_read_update_info. The warning is because building the gamma tables + * multiple times is a performance hit - it's harmless but the ability to + * call png_read_update_info() multiple times is new in 1.5.6 so it seems + * sensible to warn if the app introduces such a hit. + */ + if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) + { + png_warning(png_ptr, "gamma table being rebuilt"); + png_destroy_gamma_table(png_ptr); + } + + if (bit_depth <= 8) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_table, + png_ptr->screen_gamma > 0 ? + png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) - { - png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, - png_reciprocal(png_ptr->colorspace.gamma)); - - png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); - } + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, + png_reciprocal(png_ptr->colorspace.gamma)); + + png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, + png_ptr->screen_gamma > 0 ? + png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ - } + } #ifdef PNG_16BIT_SUPPORTED - else - { - png_byte shift, sig_bit; - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - sig_bit = png_ptr->sig_bit.red; - - if (png_ptr->sig_bit.green > sig_bit) - sig_bit = png_ptr->sig_bit.green; - - if (png_ptr->sig_bit.blue > sig_bit) - sig_bit = png_ptr->sig_bit.blue; - } - else - sig_bit = png_ptr->sig_bit.gray; - - /* 16-bit gamma code uses this equation: - * - * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] - * - * Where 'iv' is the input color value and 'ov' is the output value - - * pow(iv, gamma). - * - * Thus the gamma table consists of up to 256 256-entry tables. The table - * is selected by the (8-gamma_shift) most significant of the low 8 bits of - * the color value then indexed by the upper 8 bits: - * - * table[low bits][high 8 bits] - * - * So the table 'n' corresponds to all those 'iv' of: - * - * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> - * - */ - if (sig_bit > 0 && sig_bit < 16U) - /* shift == insignificant bits */ - shift = (png_byte)((16U - sig_bit) & 0xff); - - else - shift = 0; /* keep all 16 bits */ - - if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) - { - /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively - * the significant bits in the *input* when the output will - * eventually be 8 bits. By default it is 11. - */ - if (shift < (16U - PNG_MAX_GAMMA_8)) - shift = (16U - PNG_MAX_GAMMA_8); - } - - if (shift > 8U) - shift = 8U; /* Guarantees at least one table! */ - - png_ptr->gamma_shift = shift; - - /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now - * PNG_COMPOSE). This effectively smashed the background calculation for - * 16-bit output because the 8-bit table assumes the result will be reduced - * to 8 bits. - */ - if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) - png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); - - else - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); + else + { + png_byte shift, sig_bit; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + sig_bit = png_ptr->sig_bit.red; + + if (png_ptr->sig_bit.green > sig_bit) + sig_bit = png_ptr->sig_bit.green; + + if (png_ptr->sig_bit.blue > sig_bit) + sig_bit = png_ptr->sig_bit.blue; + } + else + sig_bit = png_ptr->sig_bit.gray; + + /* 16-bit gamma code uses this equation: + * + * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] + * + * Where 'iv' is the input color value and 'ov' is the output value - + * pow(iv, gamma). + * + * Thus the gamma table consists of up to 256 256-entry tables. The table + * is selected by the (8-gamma_shift) most significant of the low 8 bits + * of the color value then indexed by the upper 8 bits: + * + * table[low bits][high 8 bits] + * + * So the table 'n' corresponds to all those 'iv' of: + * + * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> + * + */ + if (sig_bit > 0 && sig_bit < 16U) + /* shift == insignificant bits */ + shift = (png_byte)((16U - sig_bit) & 0xff); + + else + shift = 0; /* keep all 16 bits */ + + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + { + /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively + * the significant bits in the *input* when the output will + * eventually be 8 bits. By default it is 11. + */ + if (shift < (16U - PNG_MAX_GAMMA_8)) + shift = (16U - PNG_MAX_GAMMA_8); + } + + if (shift > 8U) + shift = 8U; /* Guarantees at least one table! */ + + png_ptr->gamma_shift = shift; + + /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now + * PNG_COMPOSE). This effectively smashed the background calculation for + * 16-bit output because the 8-bit table assumes the result will be + * reduced to 8 bits. + */ + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + + else + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) - { - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, - png_reciprocal(png_ptr->colorspace.gamma)); - - /* Notice that the '16 from 1' table should be full precision, however - * the lookup on this table still uses gamma_shift, so it can't be. - * TODO: fix this. - */ - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); - } + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, + png_reciprocal(png_ptr->colorspace.gamma)); + + /* Notice that the '16 from 1' table should be full precision, however + * the lookup on this table still uses gamma_shift, so it can't be. + * TODO: fix this. + */ + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ - } + } #endif /* 16BIT */ } #endif /* READ_GAMMA */ @@ -4260,13 +4341,13 @@ png_set_option(png_structrp png_ptr, int option, int onoff) if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT && (option & 1) == 0) { - int mask = 3 << option; - int setting = (2 + (onoff != 0)) << option; - int current = png_ptr->options; + png_uint_32 mask = 3U << option; + png_uint_32 setting = (2U + (onoff != 0)) << option; + png_uint_32 current = png_ptr->options; - png_ptr->options = (png_byte)(((current & ~mask) | setting) & 0xff); + png_ptr->options = (png_uint_32)(((current & ~mask) | setting) & 0xff); - return (current & mask) >> option; + return (int)(current & mask) >> option; } return PNG_OPTION_INVALID; @@ -4278,7 +4359,7 @@ png_set_option(png_structrp png_ptr, int option, int onoff) defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) /* sRGB conversion tables; these are machine generated with the code in * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the - * specification (see the article at http://en.wikipedia.org/wiki/SRGB) + * specification (see the article at https://en.wikipedia.org/wiki/SRGB) * is used, not the gamma=1/2.2 approximation use elsewhere in libpng. * The sRGB to linear table is exact (to the nearest 16-bit linear fraction). * The inverse (linear to sRGB) table has accuracies as follows: |