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Diffstat (limited to 'contrib/libtests/pngimage.c')
| -rw-r--r-- | contrib/libtests/pngimage.c | 1618 |
1 files changed, 1618 insertions, 0 deletions
diff --git a/contrib/libtests/pngimage.c b/contrib/libtests/pngimage.c new file mode 100644 index 000000000..372845ead --- /dev/null +++ b/contrib/libtests/pngimage.c @@ -0,0 +1,1618 @@ +/* pngimage.c + * + * Copyright (c) 2014 John Cunningham Bowler + * + * Last changed in libpng 1.6.10 [March 6, 2014] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Test the png_read_png and png_write_png interfaces. Given a PNG file load it + * using png_read_png and then write with png_write_png. Test all possible + * transforms. + */ +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <stdio.h> +#include <assert.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +#ifndef PNG_SETJMP_SUPPORTED +# include <setjmp.h> /* because png.h did *not* include this */ +#endif + +#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED) +/* If a transform is valid on both read and write this implies that if the + * transform is applied to read it must also be applied on write to produce + * meaningful data. This is because these transforms when performed on read + * produce data with a memory format that does not correspond to a PNG format. + * + * Most of these transforms are invertible; after applying the transform on + * write the result is the original PNG data that would have would have been + * read if no transform were applied. + * + * The exception is _SHIFT, which destroys the low order bits marked as not + * significant in a PNG with the sBIT chunk. + * + * The following table lists, for each transform, the conditions under which it + * is expected to do anything. Conditions are defined as follows: + * + * 1) Color mask bits required - simply a mask to AND with color_type; one of + * these must be present for the transform to fire, except that 0 means + * 'always'. + * 2) Color mask bits which must be absent - another mask - none of these must + * be present. + * 3) Bit depths - a mask of component bit depths for the transform to fire. + * 4) 'read' - the transform works in png_read_png. + * 5) 'write' - the transform works in png_write_png. + * 6) PNG_INFO_chunk; a mask of the chunks that must be present for the + * transform to fire. All must be present - the requirement is that + * png_get_valid() & mask == mask, so if mask is 0 there is no requirement. + * + * The condition refers to the original image state - if multiple transforms are + * used together it is possible to cause a transform that wouldn't fire on the + * original image to fire. + */ +static struct transform_info +{ + const char *name; + int transform; + png_uint_32 valid_chunks; +# define CHUNK_NONE 0 +# define CHUNK_sBIT PNG_INFO_sBIT +# define CHUNK_tRNS PNG_INFO_tRNS + png_byte color_mask_required; + png_byte color_mask_absent; +# define COLOR_MASK_X 0 +# define COLOR_MASK_P PNG_COLOR_MASK_PALETTE +# define COLOR_MASK_C PNG_COLOR_MASK_COLOR +# define COLOR_MASK_A PNG_COLOR_MASK_ALPHA +# define COLOR_MASK_ALL (PALETTE+COLOR+ALPHA) /* absent = gray, no alpha */ + png_byte bit_depths; +# define BD_ALL (1 + 2 + 4 + 8 + 16) +# define BD_PAL (1 + 2 + 4 + 8) +# define BD_LOW (1 + 2 + 4) +# define BD_16 16 +# define BD_TRUE (8+16) /* i.e. true-color depths */ + png_byte when; +# define TRANSFORM_R 1 +# define TRANSFORM_W 2 +# define TRANSFORM_RW 3 + png_byte tested; /* the transform was tested somewhere */ +} transform_info[] = +{ + /* List ALL the PNG_TRANSFORM_ macros here. Check for support using the READ + * macros; even if the transform is supported on write it cannot be tested + * without the read support. + */ +# define T(name,chunk,cm_required,cm_absent,bd,when)\ + { #name, PNG_TRANSFORM_ ## name, CHUNK_ ## chunk,\ + COLOR_MASK_ ## cm_required, COLOR_MASK_ ## cm_absent, BD_ ## bd,\ + TRANSFORM_ ## when, 0/*!tested*/ } + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + T(STRIP_16, NONE, X, X, 16, R), + /* drops the bottom 8 bits when bit depth is 16 */ +#endif +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + T(STRIP_ALPHA, NONE, A, X, ALL, R), + /* removes the alpha channel if present */ +#endif +#ifdef PNG_WRITE_PACK_SUPPORTED +# define TRANSFORM_RW_PACK TRANSFORM_RW +#else +# define TRANSFORM_RW_PACK TRANSFORM_R +#endif +#ifdef PNG_READ_PACK_SUPPORTED + T(PACKING, NONE, X, X, LOW, RW_PACK), + /* unpacks low-bit-depth components into 1 byte per component on read, + * reverses this on write. + */ +#endif +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED +# define TRANSFORM_RW_PACKSWAP TRANSFORM_RW +#else +# define TRANSFORM_RW_PACKSWAP TRANSFORM_R +#endif +#ifdef PNG_READ_PACKSWAP_SUPPORTED + T(PACKSWAP, NONE, X, X, LOW, RW_PACKSWAP), + /* reverses the order of low-bit-depth components packed into a byte */ +#endif +#ifdef PNG_READ_EXPAND_SUPPORTED + T(EXPAND, NONE, P, X, ALL, R), + /* expands PLTE PNG files to RGB (no tRNS) or RGBA (tRNS) * + * Note that the 'EXPAND' transform does lots of different things: */ + T(EXPAND, NONE, X, C, ALL, R), + /* expands grayscale PNG files to RGB, or RGBA */ + T(EXPAND, tRNS, X, A, ALL, R), + /* expands the tRNS chunk in files without alpha */ +#endif +#ifdef PNG_WRITE_INVERT_SUPPORTED +# define TRANSFORM_RW_INVERT TRANSFORM_RW +#else +# define TRANSFORM_RW_INVERT TRANSFORM_R +#endif +#ifdef PNG_READ_INVERT_SUPPORTED + T(INVERT_MONO, NONE, X, C, ALL, RW_INVERT), + /* converts gray-scale components to 1..0 from 0..1 */ +#endif +#ifdef PNG_WRITE_SHIFT_SUPPORTED +# define TRANSFORM_RW_SHIFT TRANSFORM_RW +#else +# define TRANSFORM_RW_SHIFT TRANSFORM_R +#endif +#ifdef PNG_READ_SHIFT_SUPPORTED + T(SHIFT, sBIT, X, X, ALL, RW_SHIFT), + /* reduces component values to the original range based on the sBIT chunk, + * this is only partially reversible - the low bits are lost and cannot be + * recovered on write. In fact write code replicates the bits to generate + * new low-order bits. + */ +#endif +#ifdef PNG_WRITE_BGR_SUPPORTED +# define TRANSFORM_RW_BGR TRANSFORM_RW +#else +# define TRANSFORM_RW_BGR TRANSFORM_R +#endif +#ifdef PNG_READ_BGR_SUPPORTED + T(BGR, NONE, C, P, TRUE, RW_BGR), + /* reverses the rgb component values of true-color pixels */ +#endif +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +# define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_RW +#else +# define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_R +#endif +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + T(SWAP_ALPHA, NONE, A, X, TRUE, RW_SWAP_ALPHA), + /* swaps the alpha channel of RGBA or GA pixels to the front - ARGB or + * AG, on write reverses the process. + */ +#endif +#ifdef PNG_WRITE_SWAP_SUPPORTED +# define TRANSFORM_RW_SWAP TRANSFORM_RW +#else +# define TRANSFORM_RW_SWAP TRANSFORM_R +#endif +#ifdef PNG_READ_SWAP_SUPPORTED + T(SWAP_ENDIAN, NONE, X, P, 16, RW_SWAP), + /* byte-swaps 16-bit component values */ +#endif +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +# define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_RW +#else +# define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_R +#endif +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + T(INVERT_ALPHA, NONE, A, X, TRUE, RW_INVERT_ALPHA), + /* converts an alpha channel from 0..1 to 1..0 */ +#endif +#ifdef PNG_WRITE_FILLER_SUPPORTED + T(STRIP_FILLER_BEFORE, NONE, A, P, TRUE, W), /* 'A' for a filler! */ + /* on write skips a leading filler channel; testing requires data with a + * filler channel so this is produced from RGBA or GA images by removing + * the 'alpha' flag from the color type in place. + */ + T(STRIP_FILLER_AFTER, NONE, A, P, TRUE, W), + /* on write strips a trailing filler channel */ +#endif +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + T(GRAY_TO_RGB, NONE, X, C, ALL, R), + /* expands grayscale images to RGB, also causes the palette part of + * 'EXPAND' to happen. Low bit depth grayscale images are expanded to + * 8-bits per component and no attempt is made to convert the image to a + * palette image. While this transform is partially reversible + * png_write_png does not currently support this. + */ + T(GRAY_TO_RGB, NONE, P, X, ALL, R), + /* The 'palette' side effect mentioned above; a bit bogus but this is the + * way the libpng code works. + */ +#endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED + T(EXPAND_16, NONE, X, X, PAL, R), + /* expands images to 16-bits per component, as a side effect expands + * palette images to RGB and expands the tRNS chunk if present, so it can + * modify 16-bit per component images as well: + */ + T(EXPAND_16, tRNS, X, A, 16, R), + /* side effect of EXPAND_16 - expands the tRNS chunk in an RGB or G 16-bit + * image. + */ +#endif +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + T(SCALE_16, NONE, X, X, 16, R) + /* scales 16-bit components to 8-bits. */ +#endif + +#undef T +}; + +#define ARRAY_SIZE(a) ((sizeof a)/(sizeof a[0])) +#define TTABLE_SIZE ARRAY_SIZE(transform_info) + +/* Some combinations of options that should be reversible are not; these cases + * are bugs. + */ +static int known_bad_combos[][2] = +{ + /* problem, antidote */ + { PNG_TRANSFORM_SHIFT | PNG_TRANSFORM_INVERT_ALPHA, 0/*antidote*/ } +}; + +static int +is_combo(int transforms) +{ + return transforms & (transforms-1); /* non-zero if more than one set bit */ +} + +static int +first_transform(int transforms) +{ + return transforms & -transforms; /* lowest set bit */ +} + +static int +is_bad_combo(int transforms) +{ + unsigned int i; + + for (i=0; i<ARRAY_SIZE(known_bad_combos); ++i) + { + int combo = known_bad_combos[i][0]; + + if ((combo & transforms) == combo && + (transforms & known_bad_combos[i][1]) == 0) + return 1; + } + + return 0; /* combo is ok */ +} + +static const char * +transform_name(int t) + /* The name, if 't' has multiple bits set the name of the lowest set bit is + * returned. + */ +{ + unsigned int i; + + t &= -t; /* first set bit */ + + for (i=0; i<TTABLE_SIZE; ++i) + { + if ((transform_info[i].transform & t) != 0) + return transform_info[i].name; + } + + return "invalid transform"; +} + +/* Variables calculated by validate_T below and used to record all the supported + * transforms. Need (unsigned int) here because of the places where these + * values are used (unsigned compares in the 'exhaustive' iterator.) + */ +static unsigned int read_transforms, write_transforms, rw_transforms; + +static void +validate_T(void) + /* Validate the above table - this just builds the above values */ +{ + unsigned int i; + + for (i=0; i<TTABLE_SIZE; ++i) + { + if (transform_info[i].when & TRANSFORM_R) + read_transforms |= transform_info[i].transform; + + if (transform_info[i].when & TRANSFORM_W) + write_transforms |= transform_info[i].transform; + } + + /* Reversible transforms are those which are supported on both read and + * write. + */ + rw_transforms = read_transforms & write_transforms; +} + +/* FILE DATA HANDLING + * The original file is cached in memory. During write the output file is + * written to memory. + * + * In both cases the file data is held in a linked list of buffers - not all + * of these are in use at any time. + */ +struct buffer_list +{ + struct buffer_list *next; /* next buffer in list */ + png_byte buffer[1024]; /* the actual buffer */ +}; + +struct buffer +{ + struct buffer_list *last; /* last buffer in use */ + size_t end_count; /* bytes in the last buffer */ + struct buffer_list *current; /* current buffer being read */ + size_t read_count; /* count of bytes read from current */ + struct buffer_list first; /* the very first buffer */ +}; + +static void +buffer_init(struct buffer *buffer) + /* Call this only once for a given buffer */ +{ + buffer->first.next = NULL; + buffer->last = NULL; + buffer->current = NULL; +} + +#ifdef PNG_WRITE_SUPPORTED +static void +buffer_start_write(struct buffer *buffer) +{ + buffer->last = &buffer->first; + buffer->end_count = 0; + buffer->current = NULL; +} +#endif + +static void +buffer_start_read(struct buffer *buffer) +{ + buffer->current = &buffer->first; + buffer->read_count = 0; +} + +#ifdef ENOMEM /* required by POSIX 1003.1 */ +# define MEMORY ENOMEM +#else +# define MEMORY ERANGE /* required by ANSI-C */ +#endif +static struct buffer * +get_buffer(png_structp pp) + /* Used from libpng callbacks to get the current buffer */ +{ + return (struct buffer*)png_get_io_ptr(pp); +} + +#define NEW(type) ((type *)malloc(sizeof (type))) + +static struct buffer_list * +buffer_extend(struct buffer_list *current) +{ + struct buffer_list *add; + + assert(current->next == NULL); + + add = NEW(struct buffer_list); + if (add == NULL) + return NULL; + + add->next = NULL; + current->next = add; + + return add; +} + +/* Load a buffer from a file; does the equivalent of buffer_start_write. On a + * read error returns an errno value, else returns 0. + */ +static int +buffer_from_file(struct buffer *buffer, FILE *fp) +{ + struct buffer_list *last = &buffer->first; + size_t count = 0; + + for (;;) + { + size_t r = fread(last->buffer+count, 1/*size*/, + (sizeof last->buffer)-count, fp); + + if (r > 0) + { + count += r; + + if (count >= sizeof last->buffer) + { + assert(count == sizeof last->buffer); + count = 0; + + if (last->next == NULL) + { + last = buffer_extend(last); + if (last == NULL) + return MEMORY; + } + + else + last = last->next; + } + } + + else /* fread failed - probably end of file */ + { + if (feof(fp)) + { + buffer->last = last; + buffer->end_count = count; + return 0; /* no error */ + } + + /* Some kind of funky error; errno should be non-zero */ + return errno == 0 ? ERANGE : errno; + } + } +} + +/* This structure is used to control the test of a single file. */ +typedef enum +{ + VERBOSE, /* switches on all messages */ + INFORMATION, + WARNINGS, /* switches on warnings */ + LIBPNG_WARNING, + APP_WARNING, + ERRORS, /* just errors */ + APP_FAIL, /* continuable error - no need to longjmp */ + LIBPNG_ERROR, /* this and higher cause a longjmp */ + LIBPNG_BUG, /* erroneous behavior in libpng */ + APP_ERROR, /* such as out-of-memory in a callback */ + QUIET, /* no normal messages */ + USER_ERROR, /* such as file-not-found */ + INTERNAL_ERROR +} error_level; +#define LEVEL_MASK 0xf /* where the level is in 'options' */ + +#define EXHAUSTIVE 0x010 /* Test all combinations of active options */ +#define STRICT 0x020 /* Fail on warnings as well as errors */ +#define LOG 0x040 /* Log pass/fail to stdout */ +#define CONTINUE 0x080 /* Continue on APP_FAIL errors */ +#define SKIP_BUGS 0x100 /* Skip over known bugs */ +#define LOG_SKIPPED 0x200 /* Log skipped bugs */ +#define FIND_BAD_COMBOS 0x400 /* Attempt to deduce bad combos */ + +/* Result masks apply to the result bits in the 'results' field below; these + * bits are simple 1U<<error_level. A pass requires either nothing worse than + * warnings (--relaxes) or nothing worse than information (--strict) + */ +#define RESULT_STRICT(r) (((r) & ~((1U<<WARNINGS)-1)) == 0) +#define RESULT_RELAXED(r) (((r) & ~((1U<<ERRORS)-1)) == 0) + +struct display +{ + jmp_buf error_return; /* Where to go to on error */ + + const char *filename; /* The name of the original file */ + const char *operation; /* Operation being performed */ + int transforms; /* Transform used in operation */ + png_uint_32 options; /* See display_log below */ + png_uint_32 results; /* A mask of errors seen */ + + + png_structp original_pp; /* used on the original read */ + png_infop original_ip; /* set by the original read */ + + png_size_t original_rowbytes; /* of the original rows: */ + png_bytepp original_rows; /* from the original read */ + + /* Original chunks valid */ + png_uint_32 chunks; + + /* Original IHDR information */ + png_uint_32 width; + png_uint_32 height; + int bit_depth; + int color_type; + int interlace_method; + int compression_method; + int filter_method; + + /* Derived information for the original image. */ + int active_transforms; /* transforms that do something on read */ + int ignored_transforms; /* transforms that should do nothing */ + + /* Used on a read, both the original read and when validating a written + * image. + */ + png_structp read_pp; + png_infop read_ip; + +# ifdef PNG_WRITE_SUPPORTED + /* Used to write a new image (the original info_ptr is used) */ + png_structp write_pp; + struct buffer written_file; /* where the file gets written */ +# endif + + struct buffer original_file; /* Data read from the original file */ +}; + +static void +display_init(struct display *dp) + /* Call this only once right at the start to initialize the control + * structure, the (struct buffer) lists are maintained across calls - the + * memory is not freed. + */ +{ + memset(dp, 0, sizeof *dp); + dp->options = WARNINGS; /* default to !verbose, !quiet */ + dp->filename = NULL; + dp->operation = NULL; + dp->original_pp = NULL; + dp->original_ip = NULL; + dp->original_rows = NULL; + dp->read_pp = NULL; + dp->read_ip = NULL; + buffer_init(&dp->original_file); + +# ifdef PNG_WRITE_SUPPORTED + dp->write_pp = NULL; + buffer_init(&dp->written_file); +# endif +} + +static void +display_clean_read(struct display *dp) +{ + if (dp->read_pp != NULL) + png_destroy_read_struct(&dp->read_pp, &dp->read_ip, NULL); +} + +#ifdef PNG_WRITE_SUPPORTED +static void +display_clean_write(struct display *dp) +{ + if (dp->write_pp != NULL) + png_destroy_write_struct(&dp->write_pp, NULL); +} +#endif + +static void +display_clean(struct display *dp) +{ +# ifdef PNG_WRITE_SUPPORTED + display_clean_write(dp); +# endif + display_clean_read(dp); + + dp->original_rowbytes = 0; + dp->original_rows = NULL; + dp->chunks = 0; + + png_destroy_read_struct(&dp->original_pp, &dp->original_ip, NULL); + /* leave the filename for error detection */ + dp->results = 0; /* reset for next time */ +} + +static struct display * +get_dp(png_structp pp) + /* The display pointer is always stored in the png_struct error pointer */ +{ + struct display *dp = (struct display*)png_get_error_ptr(pp); + + if (dp == NULL) + { + fprintf(stderr, "pngimage: internal error (no display)\n"); + exit(99); /* prevents a crash */ + } + + return dp; +} + +/* error handling */ +#ifdef __GNUC__ +# define VGATTR __attribute__((__format__ (__printf__,3,4))) + /* Required to quiet GNUC warnings when the compiler sees a stdarg function + * that calls one of the stdio v APIs. + */ +#else +# define VGATTR +#endif +static void VGATTR +display_log(struct display *dp, error_level level, const char *fmt, ...) + /* 'level' is as above, fmt is a stdio style format string. This routine + * does not return if level is above LIBPNG_WARNING + */ +{ + dp->results |= 1U << level; + + if (level > (error_level)(dp->options & LEVEL_MASK)) + { + const char *lp; + va_list ap; + + switch (level) + { + case INFORMATION: lp = "information"; break; + case LIBPNG_WARNING: lp = "warning(libpng)"; break; + case APP_WARNING: lp = "warning(pngimage)"; break; + case APP_FAIL: lp = "error(continuable)"; break; + case LIBPNG_ERROR: lp = "error(libpng)"; break; + case LIBPNG_BUG: lp = "bug(libpng)"; break; + case APP_ERROR: lp = "error(pngimage)"; break; + case USER_ERROR: lp = "error(user)"; break; + + case INTERNAL_ERROR: /* anything unexpected is an internal error: */ + case VERBOSE: case WARNINGS: case ERRORS: case QUIET: + default: lp = "bug(pngimage)"; break; + } + + fprintf(stderr, "%s: %s: %s", + dp->filename != NULL ? dp->filename : "<stdin>", lp, dp->operation); + + if (dp->transforms != 0) + { + int tr = dp->transforms; + + if (is_combo(tr)) + fprintf(stderr, "(0x%x)", tr); + + else + fprintf(stderr, "(%s)", transform_name(tr)); + } + + fprintf(stderr, ": "); + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + + fputc('\n', stderr); + } + /* else do not output any message */ + + /* Errors cause this routine to exit to the fail code */ + if (level > APP_FAIL || (level > ERRORS && !(dp->options & CONTINUE))) + longjmp(dp->error_return, level); +} + +/* error handler callbacks for libpng */ +static void PNGCBAPI +display_warning(png_structp pp, png_const_charp warning) +{ + display_log(get_dp(pp), LIBPNG_WARNING, "%s", warning); +} + +static void PNGCBAPI +display_error(png_structp pp, png_const_charp error) +{ + struct display *dp = get_dp(pp); + + display_log(dp, LIBPNG_ERROR, "%s", error); +} + +static void +display_cache_file(struct display *dp, const char *filename) + /* Does the initial cache of the file. */ +{ + FILE *fp; + int ret; + + dp->filename = filename; + + if (filename != NULL) + { + fp = fopen(filename, "rb"); + if (fp == NULL) + display_log(dp, USER_ERROR, "open failed: %s", strerror(errno)); + } + + else + fp = stdin; + + ret = buffer_from_file(&dp->original_file, fp); + + fclose(fp); + + if (ret != 0) + display_log(dp, APP_ERROR, "read failed: %s", strerror(ret)); +} + +static void +buffer_read(struct display *dp, struct buffer *bp, png_bytep data, + png_size_t size) +{ + struct buffer_list *last = bp->current; + size_t read_count = bp->read_count; + + while (size > 0) + { + size_t avail; + + if (last == NULL || + (last == bp->last && read_count >= bp->end_count)) + { + display_log(dp, USER_ERROR, "file truncated (%lu bytes)", + (unsigned long)size); + /*NOTREACHED*/ + break; + } + + else if (read_count >= sizeof last->buffer) + { + /* Move to the next buffer: */ + last = last->next; + read_count = 0; + bp->current = last; /* Avoid update outside the loop */ + + /* And do a sanity check (the EOF case is caught above) */ + if (last == NULL) + { + display_log(dp, INTERNAL_ERROR, "damaged buffer list"); + /*NOTREACHED*/ + break; + } + } + + avail = (sizeof last->buffer) - read_count; + if (avail > size) + avail = size; + + memcpy(data, last->buffer + read_count, avail); + read_count += avail; + size -= avail; + data += avail; + } + + bp->read_count = read_count; +} + +static void PNGCBAPI +read_function(png_structp pp, png_bytep data, png_size_t size) +{ + buffer_read(get_dp(pp), get_buffer(pp), data, size); +} + +static void +read_png(struct display *dp, struct buffer *bp, const char *operation, + int transforms) +{ + png_structp pp; + png_infop ip; + + /* This cleans out any previous read and sets operation and transforms to + * empty. + */ + display_clean_read(dp); + + if (operation != NULL) /* else this is a verify and do not overwrite info */ + { + dp->operation = operation; + dp->transforms = transforms; + } + + dp->read_pp = pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, dp, + display_error, display_warning); + if (pp == NULL) + display_log(dp, LIBPNG_ERROR, "failed to create read struct"); + + /* The png_read_png API requires us to make the info struct, but it does the + * call to png_read_info. + */ + dp->read_ip = ip = png_create_info_struct(pp); + if (ip == NULL) + display_log(dp, LIBPNG_ERROR, "failed to create info struct"); + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + /* Remove the user limits, if any */ + png_set_user_limits(pp, 0x7fffffff, 0x7fffffff); +# endif + + /* Set the IO handling */ + buffer_start_read(bp); + png_set_read_fn(pp, bp, read_function); + + png_read_png(pp, ip, transforms, NULL/*params*/); + +#if 0 /* crazy debugging */ + { + png_bytep pr = png_get_rows(pp, ip)[0]; + size_t rb = png_get_rowbytes(pp, ip); + size_t cb; + char c = ' '; + + fprintf(stderr, "%.4x %2d (%3lu bytes):", transforms, png_get_bit_depth(pp,ip), (unsigned long)rb); + + for (cb=0; cb<rb; ++cb) + fputc(c, stderr), fprintf(stderr, "%.2x", pr[cb]), c='.'; + + fputc('\n', stderr); + } +#endif +} + +static void +update_display(struct display *dp) + /* called once after the first read to update all the info, original_pp and + * original_ip must have been filled in. + */ +{ + png_structp pp; + png_infop ip; + + /* Now perform the initial read with a 0 tranform. */ + read_png(dp, &dp->original_file, "original read", 0/*no transform*/); + + /* Move the result to the 'original' fields */ + dp->original_pp = pp = dp->read_pp, dp->read_pp = NULL; + dp->original_ip = ip = dp->read_ip, dp->read_ip = NULL; + + dp->original_rowbytes = png_get_rowbytes(pp, ip); + if (dp->original_rowbytes == 0) + display_log(dp, LIBPNG_BUG, "png_get_rowbytes returned 0"); + + dp->chunks = png_get_valid(pp, ip, 0xffffffff); + if ((dp->chunks & PNG_INFO_IDAT) == 0) /* set by png_read_png */ + display_log(dp, LIBPNG_BUG, "png_read_png did not set IDAT flag"); + + dp->original_rows = png_get_rows(pp, ip); + if (dp->original_rows == NULL) + display_log(dp, LIBPNG_BUG, "png_read_png did not create row buffers"); + + if (!png_get_IHDR(pp, ip, + &dp->width, &dp->height, &dp->bit_depth, &dp->color_type, + &dp->interlace_method, &dp->compression_method, &dp->filter_method)) + display_log(dp, LIBPNG_BUG, "png_get_IHDR failed"); + + /* 'active' transforms are discovered based on the original image format; + * running one active transform can activate others. At present the code + * does not attempt to determine the closure. + */ + { + png_uint_32 chunks = dp->chunks; + int active = 0, inactive = 0; + int ct = dp->color_type; + int bd = dp->bit_depth; + unsigned int i; + + for (i=0; i<TTABLE_SIZE; ++i) + { + int transform = transform_info[i].transform; + + if ((transform_info[i].valid_chunks == 0 || + (transform_info[i].valid_chunks & chunks) != 0) && + (transform_info[i].color_mask_required & ct) == + transform_info[i].color_mask_required && + (transform_info[i].color_mask_absent & ct) == 0 && + (transform_info[i].bit_depths & bd) != 0 && + (transform_info[i].when & TRANSFORM_R) != 0) + active |= transform; + + else if ((transform_info[i].when & TRANSFORM_R) != 0) + inactive |= transform; + } + + /* Some transforms appear multiple times in the table; the 'active' status + * is the logical OR of these and the inactive status must be adjusted to + * take this into account. + */ + inactive &= ~active; + + dp->active_transforms = active; + dp->ignored_transforms = inactive; /* excluding write-only transforms */ + + if (active == 0) + display_log(dp, INTERNAL_ERROR, "bad transform table"); + } +} + +static int +compare_read(struct display *dp, int applied_transforms) +{ + /* Compare the png_info from read_ip with original_info */ + size_t rowbytes; + png_uint_32 width, height; + int bit_depth, color_type; + int interlace_method, compression_method, filter_method; + const char *e = NULL; + + png_get_IHDR(dp->read_pp, dp->read_ip, &width, &height, &bit_depth, + &color_type, &interlace_method, &compression_method, &filter_method); + +# define C(item) if (item != dp->item) \ + display_log(dp, APP_WARNING, "IHDR " #item "(%lu) changed to %lu",\ + (unsigned long)dp->item, (unsigned long)item), e = #item + + /* The IHDR should be identical: */ + C(width); + C(height); + C(bit_depth); + C(color_type); + C(interlace_method); + C(compression_method); + C(filter_method); + + /* 'e' remains set to the name of the last thing changed: */ + if (e) + display_log(dp, APP_ERROR, "IHDR changed (%s)", e); + + /* All the chunks from the original PNG should be preserved in the output PNG + * because the PNG format has not been changed. + */ + { + unsigned long chunks = + png_get_valid(dp->read_pp, dp->read_ip, 0xffffffff); + + if (chunks != dp->chunks) + display_log(dp, APP_FAIL, "PNG chunks changed from 0x%lx to 0x%lx", + (unsigned long)dp->chunks, chunks); + } + + /* rowbytes should be the same */ + rowbytes = png_get_rowbytes(dp->read_pp, dp->read_ip); + + /* NOTE: on 64-bit systems this may trash the top bits of rowbytes, + * which could lead to weird error messages. + */ + if (rowbytes != dp->original_rowbytes) + display_log(dp, APP_ERROR, "PNG rowbytes changed from %lu to %lu", + (unsigned long)dp->original_rowbytes, (unsigned long)rowbytes); + + /* The rows should be the same too, unless the applied transforms includes + * the shift transform, in which case low bits may have been lost. + */ + { + png_bytepp rows = png_get_rows(dp->read_pp, dp->read_ip); + unsigned int mask; /* mask (if not zero) for the final byte */ + + if (bit_depth < 8) + { + /* Need the stray bits at the end, this depends only on the low bits + * of the image width; overflow does not matter. If the width is an + * exact multiple of 8 bits this gives a mask of 0, not 0xff. + */ + mask = 0xff & (0xff00 >> ((bit_depth * width) & 7)); + } + + else + mask = 0; + + if (rows == NULL) + display_log(dp, LIBPNG_BUG, "png_get_rows returned NULL"); + + if ((applied_transforms & PNG_TRANSFORM_SHIFT) == 0 || + (dp->active_transforms & PNG_TRANSFORM_SHIFT) == 0 || + color_type == PNG_COLOR_TYPE_PALETTE) + { + unsigned long y; + + for (y=0; y<height; ++y) + { + png_bytep row = rows[y]; + png_bytep orig = dp->original_rows[y]; + + if (memcmp(row, orig, rowbytes-(mask != 0)) != 0 || (mask != 0 && + ((row[rowbytes-1] & mask) != (orig[rowbytes-1] & mask)))) + { + size_t x; + + /* Find the first error */ + for (x=0; x<rowbytes-1; ++x) if (row[x] != orig[x]) + break; + + display_log(dp, APP_FAIL, + "byte(%lu,%lu) changed 0x%.2x -> 0x%.2x", + (unsigned long)x, (unsigned long)y, orig[x], row[x]); + return 0; /* don't keep reporting failed rows on 'continue' */ + } + } + } + + else + { + unsigned long y; + int bpp; /* bits-per-pixel then bytes-per-pixel */ + /* components are up to 8 bytes in size */ + png_byte sig_bits[8]; + png_color_8p sBIT; + + if (png_get_sBIT(dp->read_pp, dp->read_ip, &sBIT) != PNG_INFO_sBIT) + display_log(dp, INTERNAL_ERROR, + "active shift transform but no sBIT in file"); + + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + sig_bits[0] = sBIT->gray; + bpp = bit_depth; + break; + + case PNG_COLOR_TYPE_GA: + sig_bits[0] = sBIT->gray; + sig_bits[1] = sBIT->alpha; + bpp = 2 * bit_depth; + break; + + case PNG_COLOR_TYPE_RGB: + sig_bits[0] = sBIT->red; + sig_bits[1] = sBIT->green; + sig_bits[2] = sBIT->blue; + bpp = 3 * bit_depth; + break; + + case PNG_COLOR_TYPE_RGBA: + sig_bits[0] = sBIT->red; + sig_bits[1] = sBIT->green; + sig_bits[2] = sBIT->blue; + sig_bits[3] = sBIT->alpha; + bpp = 4 * bit_depth; + break; + + default: + display_log(dp, LIBPNG_ERROR, "invalid colour type %d", + color_type); + /*NOTREACHED*/ + bpp = 0; + break; + } + + { + int b; + + for (b=0; 8*b<bpp; ++b) + { + /* libpng should catch this; if not there is a security issue + * because an app (like this one) may overflow an array. In fact + * libpng doesn't catch this at present. + */ + if (sig_bits[b] == 0 || sig_bits[b] > bit_depth/*!palette*/) + display_log(dp, LIBPNG_BUG, + "invalid sBIT[%u] value %d returned for PNG bit depth %d", + b, sig_bits[b], bit_depth); + } + } + + if (bpp < 8 && bpp != bit_depth) + { + /* sanity check; this is a grayscale PNG; something is wrong in the + * code above. + */ + display_log(dp, INTERNAL_ERROR, "invalid bpp %u for bit_depth %u", + bpp, bit_depth); + } + + switch (bit_depth) + { + int b; + + case 16: /* Two bytes per component, bit-endian */ + for (b = (bpp >> 4); b > 0; ) + { + unsigned int sig = (unsigned int)(0xffff0000 >> sig_bits[b]); + + sig_bits[2*b+1] = (png_byte)sig; + sig_bits[2*b+0] = (png_byte)(sig >> 8); /* big-endian */ + } + break; + + case 8: /* One byte per component */ + for (b=0; b*8 < bpp; ++b) + sig_bits[b] = (png_byte)(0xff00 >> sig_bits[b]); + break; + + case 1: /* allowed, but dumb */ + /* Value is 1 */ + sig_bits[0] = 0xff; + break; + + case 2: /* Replicate 4 times */ + /* Value is 1 or 2 */ + b = 0x3 & ((0x3<<2) >> sig_bits[0]); + b |= b << 2; + b |= b << 4; + sig_bits[0] = (png_byte)b; + break; + + case 4: /* Relicate twice */ + /* Value is 1, 2, 3 or 4 */ + b = 0xf & ((0xf << 4) >> sig_bits[0]); + b |= b << 4; + sig_bits[0] = (png_byte)b; + break; + + default: + display_log(dp, LIBPNG_BUG, "invalid bit depth %d", bit_depth); + break; + } + + /* Convert bpp to bytes; this gives '1' for low-bit depth grayscale, + * where there are multiple pixels per byte. + */ + bpp = (bpp+7) >> 3; + + /* The mask can be combined with sig_bits[0] */ + if (mask != 0) + { + mask &= sig_bits[0]; + + if (bpp != 1 || mask == 0) + display_log(dp, INTERNAL_ERROR, "mask calculation error %u, %u", + bpp, mask); + } + + for (y=0; y<height; ++y) + { + png_bytep row = rows[y]; + png_bytep orig = dp->original_rows[y]; + unsigned long x; + + for (x=0; x<(width-(mask!=0)); ++x) + { + int b; + + for (b=0; b<bpp; ++b) + { + if ((*row++ & sig_bits[b]) != (*orig++ & sig_bits[b])) + { + display_log(dp, APP_FAIL, + "significant bits at (%lu[%u],%lu) changed %.2x->%.2x", + x, b, y, orig[-1], row[-1]); + return 0; + } + } + } + + if (mask != 0 && (*row & mask) != (*orig & mask)) + { + display_log(dp, APP_FAIL, + "significant bits at (%lu[end],%lu) changed", x, y); + return 0; + } + } /* for y */ + } + } + + return 1; /* compare succeeded */ +} + +#ifdef PNG_WRITE_SUPPORTED +static void +buffer_write(struct display *dp, struct buffer *buffer, png_bytep data, + png_size_t size) + /* Generic write function used both from the write callback provided to + * libpng and from the generic read code. + */ +{ + /* Write the data into the buffer, adding buffers as required */ + struct buffer_list *last = buffer->last; + size_t end_count = buffer->end_count; + + while (size > 0) + { + size_t avail; + + if (end_count >= sizeof last->buffer) + { + if (last->next == NULL) + { + last = buffer_extend(last); + + if (last == NULL) + display_log(dp, APP_ERROR, "out of memory saving file"); + } + + else + last = last->next; + + buffer->last = last; /* avoid the need to rewrite every time */ + end_count = 0; + } + + avail = (sizeof last->buffer) - end_count; + if (avail > size) + avail = size; + + memcpy(last->buffer + end_count, data, avail); + end_count += avail; + size -= avail; + data += avail; + } + + buffer->end_count = end_count; +} + +static void PNGCBAPI +write_function(png_structp pp, png_bytep data, png_size_t size) +{ + buffer_write(get_dp(pp), get_buffer(pp), data, size); +} + +static void +write_png(struct display *dp, png_infop ip, int transforms) +{ + display_clean_write(dp); /* safety */ + + buffer_start_write(&dp->written_file); + dp->operation = "write"; + dp->transforms = transforms; + + dp->write_pp = png_create_write_struct(PNG_LIBPNG_VER_STRING, dp, + display_error, display_warning); + + if (dp->write_pp == NULL) + display_log(dp, APP_ERROR, "failed to create write png_struct"); + + png_set_write_fn(dp->write_pp, &dp->written_file, write_function, + NULL/*flush*/); + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + /* Remove the user limits, if any */ + png_set_user_limits(dp->write_pp, 0x7fffffff, 0x7fffffff); +# endif + + /* Certain transforms require the png_info to be zapped to allow the + * transform to work correctly. + */ + if (transforms & (PNG_TRANSFORM_PACKING| + PNG_TRANSFORM_STRIP_FILLER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) + { + int ct = dp->color_type; + + if (transforms & (PNG_TRANSFORM_STRIP_FILLER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) + ct &= ~PNG_COLOR_MASK_ALPHA; + + png_set_IHDR(dp->write_pp, ip, dp->width, dp->height, dp->bit_depth, ct, + dp->interlace_method, dp->compression_method, dp->filter_method); + } + + png_write_png(dp->write_pp, ip, transforms, NULL/*params*/); + + /* Clean it on the way out - if control returns to the caller then the + * written_file contains the required data. + */ + display_clean_write(dp); +} +#endif /* WRITE_SUPPORTED */ + +static int +skip_transform(struct display *dp, int tr) + /* Helper to test for a bad combo and log it if it is skipped */ +{ + if ((dp->options & SKIP_BUGS) != 0 && is_bad_combo(tr)) + { + /* Log this to stdout if logging is on, otherwise just do an information + * display_log. + */ + if ((dp->options & LOG_SKIPPED) != 0) + { + printf("SKIP: %s transforms ", dp->filename); + + while (tr != 0) + { + int next = first_transform(tr); + tr &= ~next; + + printf("%s", transform_name(next)); + if (tr != 0) + putchar('+'); + } + + putchar('\n'); + } + + else + display_log(dp, INFORMATION, "%s: skipped known bad combo 0x%x", + dp->filename, tr); + + return 1; /* skip */ + } + + return 0; /* don't skip */ +} + +static void +test_one_file(struct display *dp, const char *filename) +{ + /* First cache the file and update the display original file + * information for the new file. + */ + dp->operation = "cache file"; + dp->transforms = 0; + display_cache_file(dp, filename); + update_display(dp); + + /* First test: if there are options that should be ignored for this file + * verify that they really are ignored. + */ + if (dp->ignored_transforms != 0) + { + read_png(dp, &dp->original_file, "ignored transforms", + dp->ignored_transforms); + + /* The result should be identical to the original_rows */ + if (!compare_read(dp, 0/*transforms applied*/)) + return; /* no point testing more */ + } + +#ifdef PNG_WRITE_SUPPORTED + /* Second test: write the original PNG data out to a new file (to test the + * write side) then read the result back in and make sure that it hasn't + * changed. + */ + dp->operation = "write"; + write_png(dp, dp->original_ip, 0/*transforms*/); + read_png(dp, &dp->written_file, NULL, 0/*transforms*/); + if (!compare_read(dp, 0/*transforms applied*/)) + return; +#endif + + /* Third test: the active options. Test each in turn, or, with the + * EXHAUSTIVE option, test all possible combinations. + */ + { + /* Use unsigned int here because the code below to increment through all + * the possibilities exhaustively has to use a compare and that must be + * unsigned, because some transforms are negative on a 16-bit system. + */ + unsigned int active = dp->active_transforms; + const int exhaustive = (dp->options & EXHAUSTIVE) != 0; + unsigned int current = first_transform(active); + unsigned int bad_transforms = 0; + unsigned int bad_combo = ~0U; /* bitwise AND of failing transforms */ + unsigned int bad_combo_list = 0; /* bitwise OR of failures */ + + for (;;) + { + read_png(dp, &dp->original_file, "active transforms", current); + + /* If this involved any irreversible transformations then if we write + * it out with just the reversible transformations and read it in again + * with the same transforms we should get the same thing. At present + * this isn't done - it just seems like a waste of time and it would + * require two sets of read png_struct/png_info. + * + * If there were no irreversible transformations then if we write it + * out and read it back in again (without the reversible transforms) + * we should get back to the place where we started. + */ +#ifdef PNG_WRITE_SUPPORTED + if ((current & write_transforms) == current) + { + /* All transforms reversible: write the PNG with the transformations + * reversed, then read it back in with no transformations. The + * result should be the same as the original apart from the loss of + * low order bits because of the SHIFT/sBIT transform. + */ + dp->operation = "reversible transforms"; + write_png(dp, dp->read_ip, current); + + /* And if this is read back in, because all the transformations were + * reversible, the result should be the same. + */ + read_png(dp, &dp->written_file, NULL, 0); + if (!compare_read(dp, current/*for the SHIFT/sBIT transform*/)) + { + /* This set of transforms failed. If a single bit is set - if + * there is just one transform - don't include this in further + * 'exhaustive' tests. Notice that each transform is tested on + * its own before testing combos in the exhaustive case. + */ + if (is_combo(current)) + { + bad_combo &= current; + bad_combo_list |= current; + } + + else + bad_transforms |= current; + } + } +#endif + + /* Now move to the next transform */ + if (exhaustive) /* all combinations */ + { + unsigned int next = current; + + do + { + if (next == read_transforms) /* Everything tested */ + goto combo; + + ++next; + } /* skip known bad combos if the relevant option is set; skip + * combos involving known bad single transforms in all cases. + */ + while ( (next & read_transforms) <= current + || (next & active) == 0 /* skip cases that do nothing */ + || (next & bad_transforms) != 0 + || skip_transform(dp, next)); + + assert((next & read_transforms) == next); + current = next; + } + + else /* one at a time */ + { + active &= ~current; + + if (active == 0) + goto combo; + + current = first_transform(active); + } + } + +combo: + if (dp->options & FIND_BAD_COMBOS) + { + /* bad_combos identifies the combos that occur in all failing cases; + * bad_combo_list identifies transforms that do not prevent the + * failure. + */ + if (bad_combo != ~0U) + printf("%s[0x%x]: PROBLEM: 0x%x[0x%x] ANTIDOTE: 0x%x\n", + dp->filename, active, bad_combo, bad_combo_list, + rw_transforms & ~bad_combo_list); + + else + printf("%s: no %sbad combos found\n", dp->filename, + (dp->options & SKIP_BUGS) ? "additional " : ""); + } + } +} + +static int +do_test(struct display *dp, const char *file) + /* Exists solely to isolate the setjmp clobbers */ +{ + int ret = setjmp(dp->error_return); + + if (ret == 0) + { + test_one_file(dp, file); + return 0; + } + + else if (ret < ERRORS) /* shouldn't longjmp on warnings */ + display_log(dp, INTERNAL_ERROR, "unexpected return code %d", ret); + + return ret; +} + +int +main(const int argc, const char * const * const argv) +{ + /* For each file on the command line test it with a range of transforms */ + int option_end, ilog = 0; + struct display d; + + validate_T(); + display_init(&d); + + for (option_end=1; option_end<argc; ++option_end) + { + const char *name = argv[option_end]; + + if (strcmp(name, "--verbose") == 0) + d.options = (d.options & ~LEVEL_MASK) | VERBOSE; + + else if (strcmp(name, "--warnings") == 0) + d.options = (d.options & ~LEVEL_MASK) | WARNINGS; + + else if (strcmp(name, "--errors") == 0) + d.options = (d.options & ~LEVEL_MASK) | ERRORS; + + else if (strcmp(name, "--quiet") == 0) + d.options = (d.options & ~LEVEL_MASK) | QUIET; + + else if (strcmp(name, "--exhaustive") == 0) + d.options |= EXHAUSTIVE; + + else if (strcmp(name, "--fast") == 0) + d.options &= ~EXHAUSTIVE; + + else if (strcmp(name, "--strict") == 0) + d.options |= STRICT; + + else if (strcmp(name, "--relaxed") == 0) + d.options &= ~STRICT; + + else if (strcmp(name, "--log") == 0) + { + ilog = option_end; /* prevent display */ + d.options |= LOG; + } + + else if (strcmp(name, "--nolog") == 0) + d.options &= ~LOG; + + else if (strcmp(name, "--continue") == 0) + d.options |= CONTINUE; + + else if (strcmp(name, "--stop") == 0) + d.options &= ~CONTINUE; + + else if (strcmp(name, "--skip-bugs") == 0) + d.options |= SKIP_BUGS; + + else if (strcmp(name, "--test-all") == 0) + d.options &= ~SKIP_BUGS; + + else if (strcmp(name, "--log-skipped") == 0) + d.options |= LOG_SKIPPED; + + else if (strcmp(name, "--nolog-skipped") == 0) + d.options &= ~LOG_SKIPPED; + + else if (strcmp(name, "--find-bad-combos") == 0) + d.options |= FIND_BAD_COMBOS; + + else if (strcmp(name, "--nofind-bad-combos") == 0) + d.options &= ~FIND_BAD_COMBOS; + + else if (name[0] == '-' && name[1] == '-') + { + fprintf(stderr, "pngimage: %s: unknown option\n", name); + return 99; + } + + else + break; /* Not an option */ + } + + { + int i; + int errors = 0; + + for (i=option_end; i<argc; ++i) + { + { + int ret = do_test(&d, argv[i]); + + if (ret > QUIET) /* abort on user or internal error */ + return 99; + } + + /* Here on any return, including failures, except user/internal issues + */ + { + const int pass = (d.options & STRICT) ? + RESULT_STRICT(d.results) : RESULT_RELAXED(d.results); + + if (!pass) + ++errors; + + if (d.options & LOG) + { + int j; + + printf("%s: pngimage ", pass ? "PASS" : "FAIL"); + + for (j=1; j<option_end; ++j) if (j != ilog) + printf("%s ", argv[j]); + + printf("%s\n", d.filename); + } + } + + display_clean(&d); + } + + return errors != 0; + } +} +#else /* !PNG_INFO_IMAGE_SUPPORTED || !PNG_READ_SUPPORTED */ +int +main(void) +{ + fprintf(stderr, "pngimage: no support for png_read/write_image\n"); + return 77; +} +#endif |