diff options
Diffstat (limited to 'pngrutil.c')
| -rw-r--r-- | pngrutil.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/pngrutil.c b/pngrutil.c index 715c20df6..7d5b14b22 100644 --- a/pngrutil.c +++ b/pngrutil.c @@ -1,7 +1,7 @@ /* pngrutil.c - utilities to read a PNG file * - * libpng 1.0.9beta5 - December 15, 2000 + * libpng 1.0.9beta6 - December 18, 2000 * For conditions of distribution and use, see copyright notice in png.h * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) @@ -353,15 +353,31 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (compression_type != PNG_COMPRESSION_TYPE_BASE) png_error(png_ptr, "Unknown compression method in IHDR"); - if( #if defined(PNG_MNG_FEATURES_SUPPORTED) - !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + /* Accept filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not read a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&png_ptr->mng_features_permitted) + png_warning(png_ptr,"MNG features are not allowed in a PNG datastream\n"); + if(!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && (filter_type == PNG_INTRAPIXEL_DIFFERENCING) && + ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && -#endif - filter_type != PNG_FILTER_TYPE_BASE) + filter_type != PNG_FILTER_TYPE_BASE) + png_error(png_ptr, "Unknown filter method in IHDR"); + if(filter_type != PNG_FILTER_TYPE_BASE) + png_warning(png_ptr, "Invalid filter method in IHDR"); +#else + if(filter_type != PNG_FILTER_TYPE_BASE) png_error(png_ptr, "Unknown filter method in IHDR"); +#endif /* set internal variables */ png_ptr->width = width; |