/* Derived from zlib fuzzers at http://github.com/google/oss-fuzz/tree/master/projects/zlib,

 * see ossfuzz.sh for full license text.

 */

#include <stdio.h>

#include <stddef.h>

#include <stdint.h>

#include <string.h>

#include <stdlib.h>

#include <inttypes.h>

#include "miniz.h"

#define CHECK_ERR(err, msg)                              \

    {                                                    \

        if (err != Z_OK)                                 \

        {                                                \

            fprintf(stderr, "%s error: %d\n", msg, err); \

            exit(1);                                     \

        }                                                \

    }

static const uint8_t *data;

static size_t dataLen;

static alloc_func zalloc = NULL;

static free_func zfree = NULL;

void test_flush(unsigned char *compr, size_t *comprLen)

{

    z_stream c_stream; /* compression stream */

    int err;

    unsigned int len = dataLen;

    c_stream.zalloc = zalloc;

    c_stream.zfree = zfree;

    c_stream.opaque = NULL;

    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);

    CHECK_ERR(err, "deflateInit");

    c_stream.next_in = (Bytef *)data;

    c_stream.next_out = compr;

    c_stream.avail_in = 3;

    c_stream.avail_out = (unsigned int)*comprLen;

    err = deflate(&c_stream, Z_FULL_FLUSH);

    CHECK_ERR(err, "deflate flush 1");

    compr[3]++; /* force an error in first compressed block */

    c_stream.avail_in = len - 3;

    err = deflate(&c_stream, Z_FINISH);

    if (err != Z_STREAM_END)

    {

        CHECK_ERR(err, "deflate flush 2");

    }

    err = deflateEnd(&c_stream);

    CHECK_ERR(err, "deflateEnd");

    *comprLen = (size_t)c_stream.total_out;

}

int LLVMFuzzerTestOneInput(const uint8_t *d, size_t size)

{

    size_t comprLen = 100 + 2 * compressBound(size);

    size_t uncomprLen = size;

    uint8_t *compr, *uncompr;

    /* Discard inputs larger than 1Mb. */

    static const size_t kMaxSize = 1024 * 1024;

    /* This test requires at least 3 bytes of input data. */

    if (size <= 3 || size > kMaxSize)

        return 0;

    data = d;

    dataLen = size;

    compr = calloc(1, comprLen);

    uncompr = calloc(1, uncomprLen);

    test_flush(compr, &comprLen);

    free(compr);

    free(uncompr);

    return 0;

}