summaryrefslogtreecommitdiff
path: root/win32/zlib/test/infcover.c
blob: fe3d9203a023777a82572e9aa38449a066d7c07b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
/* infcover.c -- test zlib's inflate routines with full code coverage
 * Copyright (C) 2011 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* to use, do: ./configure --cover && make cover */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "zlib.h"

/* get definition of internal structure so we can mess with it (see pull()),
   and so we can call inflate_trees() (see cover5()) */
#define ZLIB_INTERNAL
#include "inftrees.h"
#include "inflate.h"

#define local static

/* -- memory tracking routines -- */

/*
   These memory tracking routines are provided to zlib and track all of zlib's
   allocations and deallocations, check for LIFO operations, keep a current
   and high water mark of total bytes requested, optionally set a limit on the
   total memory that can be allocated, and when done check for memory leaks.

   They are used as follows:

   z_stream strm;
   mem_setup(&strm)         initializes the memory tracking and sets the
                            zalloc, zfree, and opaque members of strm to use
                            memory tracking for all zlib operations on strm
   mem_limit(&strm, limit)  sets a limit on the total bytes requested -- a
                            request that exceeds this limit will result in an
                            allocation failure (returns NULL) -- setting the
                            limit to zero means no limit, which is the default
                            after mem_setup()
   mem_used(&strm, "msg")   prints to stderr "msg" and the total bytes used
   mem_high(&strm, "msg")   prints to stderr "msg" and the high water mark
   mem_done(&strm, "msg")   ends memory tracking, releases all allocations
                            for the tracking as well as leaked zlib blocks, if
                            any.  If there was anything unusual, such as leaked
                            blocks, non-FIFO frees, or frees of addresses not
                            allocated, then "msg" and information about the
                            problem is printed to stderr.  If everything is
                            normal, nothing is printed. mem_done resets the
                            strm members to Z_NULL to use the default memory
                            allocation routines on the next zlib initialization
                            using strm.
 */

/* these items are strung together in a linked list, one for each allocation */
struct mem_item {
    void *ptr;                  /* pointer to allocated memory */
    size_t size;                /* requested size of allocation */
    struct mem_item *next;      /* pointer to next item in list, or NULL */
};

/* this structure is at the root of the linked list, and tracks statistics */
struct mem_zone {
    struct mem_item *first;     /* pointer to first item in list, or NULL */
    size_t total, highwater;    /* total allocations, and largest total */
    size_t limit;               /* memory allocation limit, or 0 if no limit */
    int notlifo, rogue;         /* counts of non-LIFO frees and rogue frees */
};

/* memory allocation routine to pass to zlib */
local void *mem_alloc(void *mem, unsigned count, unsigned size)
{
    void *ptr;
    struct mem_item *item;
    struct mem_zone *zone = mem;
    size_t len = count * (size_t)size;

    /* induced allocation failure */
    if (zone == NULL || (zone->limit && zone->total + len > zone->limit))
        return NULL;

    /* perform allocation using the standard library, fill memory with a
       non-zero value to make sure that the code isn't depending on zeros */
    ptr = malloc(len);
    if (ptr == NULL)
        return NULL;
    memset(ptr, 0xa5, len);

    /* create a new item for the list */
    item = malloc(sizeof(struct mem_item));
    if (item == NULL) {
        free(ptr);
        return NULL;
    }
    item->ptr = ptr;
    item->size = len;

    /* insert item at the beginning of the list */
    item->next = zone->first;
    zone->first = item;

    /* update the statistics */
    zone->total += item->size;
    if (zone->total > zone->highwater)
        zone->highwater = zone->total;

    /* return the allocated memory */
    return ptr;
}

/* memory free routine to pass to zlib */
local void mem_free(void *mem, void *ptr)
{
    struct mem_item *item, *next;
    struct mem_zone *zone = mem;

    /* if no zone, just do a free */
    if (zone == NULL) {
        free(ptr);
        return;
    }

    /* point next to the item that matches ptr, or NULL if not found -- remove
       the item from the linked list if found */
    next = zone->first;
    if (next) {
        if (next->ptr == ptr)
            zone->first = next->next;   /* first one is it, remove from list */
        else {
            do {                        /* search the linked list */
                item = next;
                next = item->next;
            } while (next != NULL && next->ptr != ptr);
            if (next) {                 /* if found, remove from linked list */
                item->next = next->next;
                zone->notlifo++;        /* not a LIFO free */
            }

        }
    }

    /* if found, update the statistics and free the item */
    if (next) {
        zone->total -= next->size;
        free(next);
    }

    /* if not found, update the rogue count */
    else
        zone->rogue++;

    /* in any case, do the requested free with the standard library function */
    free(ptr);
}

/* set up a controlled memory allocation space for monitoring, set the stream
   parameters to the controlled routines, with opaque pointing to the space */
local void mem_setup(z_stream *strm)
{
    struct mem_zone *zone;

    zone = malloc(sizeof(struct mem_zone));
    assert(zone != NULL);
    zone->first = NULL;
    zone->total = 0;
    zone->highwater = 0;
    zone->limit = 0;
    zone->notlifo = 0;
    zone->rogue = 0;
    strm->opaque = zone;
    strm->zalloc = mem_alloc;
    strm->zfree = mem_free;
}

/* set a limit on the total memory allocation, or 0 to remove the limit */
local void mem_limit(z_stream *strm, size_t limit)
{
    struct mem_zone *zone = strm->opaque;

    zone->limit = limit;
}

/* show the current total requested allocations in bytes */
local void mem_used(z_stream *strm, char *prefix)
{
    struct mem_zone *zone = strm->opaque;

    fprintf(stderr, "%s: %lu allocated\n", prefix, zone->total);
}

/* show the high water allocation in bytes */
local void mem_high(z_stream *strm, char *prefix)
{
    struct mem_zone *zone = strm->opaque;

    fprintf(stderr, "%s: %lu high water mark\n", prefix, zone->highwater);
}

/* release the memory allocation zone -- if there are any surprises, notify */
local void mem_done(z_stream *strm, char *prefix)
{
    int count = 0;
    struct mem_item *item, *next;
    struct mem_zone *zone = strm->opaque;

    /* show high water mark */
    mem_high(strm, prefix);

    /* free leftover allocations and item structures, if any */
    item = zone->first;
    while (item != NULL) {
        free(item->ptr);
        next = item->next;
        free(item);
        item = next;
        count++;
    }

    /* issue alerts about anything unexpected */
    if (count || zone->total)
        fprintf(stderr, "** %s: %lu bytes in %d blocks not freed\n",
                prefix, zone->total, count);
    if (zone->notlifo)
        fprintf(stderr, "** %s: %d frees not LIFO\n", prefix, zone->notlifo);
    if (zone->rogue)
        fprintf(stderr, "** %s: %d frees not recognized\n",
                prefix, zone->rogue);

    /* free the zone and delete from the stream */
    free(zone);
    strm->opaque = Z_NULL;
    strm->zalloc = Z_NULL;
    strm->zfree = Z_NULL;
}

/* -- inflate test routines -- */

/* Decode a hexadecimal string, set *len to length, in[] to the bytes.  This
   decodes liberally, in that hex digits can be adjacent, in which case two in
   a row writes a byte.  Or they can delimited by any non-hex character, where
   the delimiters are ignored except when a single hex digit is followed by a
   delimiter in which case that single digit writes a byte.  The returned
   data is allocated and must eventually be freed.  NULL is returned if out of
   memory.  If the length is not needed, then len can be NULL. */
local unsigned char *h2b(const char *hex, unsigned *len)
{
    unsigned char *in;
    unsigned next, val;

    in = malloc((strlen(hex) + 1) >> 1);
    if (in == NULL)
        return NULL;
    next = 0;
    val = 1;
    do {
        if (*hex >= '0' && *hex <= '9')
            val = (val << 4) + *hex - '0';
        else if (*hex >= 'A' && *hex <= 'F')
            val = (val << 4) + *hex - 'A' + 10;
        else if (*hex >= 'a' && *hex <= 'f')
            val = (val << 4) + *hex - 'a' + 10;
        else if (val != 1 && val < 32)  /* one digit followed by delimiter */
            val += 240;                 /* make it look like two digits */
        if (val > 255) {                /* have two digits */
            in[next++] = val & 0xff;    /* save the decoded byte */
            val = 1;                    /* start over */
        }
    } while (*hex++);       /* go through the loop with the terminating null */
    if (len != NULL)
        *len = next;
    in = reallocf(in, next);
    return in;
}

/* generic inflate() run, where hex is the hexadecimal input data, what is the
   text to include in an error message, step is how much input data to feed
   inflate() on each call, or zero to feed it all, win is the window bits
   parameter to inflateInit2(), len is the size of the output buffer, and err
   is the error code expected from the first inflate() call (the second
   inflate() call is expected to return Z_STREAM_END).  If win is 47, then
   header information is collected with inflateGetHeader().  If a zlib stream
   is looking for a dictionary, then an empty dictionary is provided.
   inflate() is run until all of the input data is consumed. */
local void inf(char *hex, char *what, unsigned step, int win, unsigned len,
               int err)
{
    int ret;
    unsigned have;
    unsigned char *in, *out;
    z_stream strm, copy;
    gz_header head;

    mem_setup(&strm);
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit2(&strm, win);
    if (ret != Z_OK) {
        mem_done(&strm, what);
        return;
    }
    out = malloc(len);                          assert(out != NULL);
    if (win == 47) {
        head.extra = out;
        head.extra_max = len;
        head.name = out;
        head.name_max = len;
        head.comment = out;
        head.comm_max = len;
        ret = inflateGetHeader(&strm, &head);   assert(ret == Z_OK);
    }
    in = h2b(hex, &have);                       assert(in != NULL);
    if (step == 0 || step > have)
        step = have;
    strm.avail_in = step;
    have -= step;
    strm.next_in = in;
    do {
        strm.avail_out = len;
        strm.next_out = out;
        ret = inflate(&strm, Z_NO_FLUSH);       assert(err == 9 || ret == err);
        if (ret != Z_OK && ret != Z_BUF_ERROR && ret != Z_NEED_DICT)
            break;
        if (ret == Z_NEED_DICT) {
            ret = inflateSetDictionary(&strm, in, 1);
                                                assert(ret == Z_DATA_ERROR);
            mem_limit(&strm, 1);
            ret = inflateSetDictionary(&strm, out, 0);
                                                assert(ret == Z_MEM_ERROR);
            mem_limit(&strm, 0);
            ((struct inflate_state *)strm.state)->mode = DICT;
            ret = inflateSetDictionary(&strm, out, 0);
                                                assert(ret == Z_OK);
            ret = inflate(&strm, Z_NO_FLUSH);   assert(ret == Z_BUF_ERROR);
        }
        ret = inflateCopy(&copy, &strm);        assert(ret == Z_OK);
        ret = inflateEnd(&copy);                assert(ret == Z_OK);
        err = 9;                        /* don't care next time around */
        have += strm.avail_in;
        strm.avail_in = step > have ? have : step;
        have -= strm.avail_in;
    } while (strm.avail_in);
    free(in);
    free(out);
    ret = inflateReset2(&strm, -8);             assert(ret == Z_OK);
    ret = inflateEnd(&strm);                    assert(ret == Z_OK);
    mem_done(&strm, what);
}

/* cover all of the lines in inflate.c up to inflate() */
local void cover_support(void)
{
    int ret;
    z_stream strm;

    mem_setup(&strm);
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit(&strm);                   assert(ret == Z_OK);
    mem_used(&strm, "inflate init");
    ret = inflatePrime(&strm, 5, 31);           assert(ret == Z_OK);
    ret = inflatePrime(&strm, -1, 0);           assert(ret == Z_OK);
    ret = inflateSetDictionary(&strm, Z_NULL, 0);
                                                assert(ret == Z_STREAM_ERROR);
    ret = inflateEnd(&strm);                    assert(ret == Z_OK);
    mem_done(&strm, "prime");

    inf("63 0", "force window allocation", 0, -15, 1, Z_OK);
    inf("63 18 5", "force window replacement", 0, -8, 259, Z_OK);
    inf("63 18 68 30 d0 0 0", "force split window update", 4, -8, 259, Z_OK);
    inf("3 0", "use fixed blocks", 0, -15, 1, Z_STREAM_END);
    inf("", "bad window size", 0, 1, 0, Z_STREAM_ERROR);

    mem_setup(&strm);
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit_(&strm, ZLIB_VERSION - 1, (int)sizeof(z_stream));
                                                assert(ret == Z_VERSION_ERROR);
    mem_done(&strm, "wrong version");

    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit(&strm);                   assert(ret == Z_OK);
    ret = inflateEnd(&strm);                    assert(ret == Z_OK);
    fputs("inflate built-in memory routines\n", stderr);
}

/* cover all inflate() header and trailer cases and code after inflate() */
local void cover_wrap(void)
{
    int ret;
    z_stream strm, copy;
    unsigned char dict[257];

    ret = inflate(Z_NULL, 0);                   assert(ret == Z_STREAM_ERROR);
    ret = inflateEnd(Z_NULL);                   assert(ret == Z_STREAM_ERROR);
    ret = inflateCopy(Z_NULL, Z_NULL);          assert(ret == Z_STREAM_ERROR);
    fputs("inflate bad parameters\n", stderr);

    inf("1f 8b 0 0", "bad gzip method", 0, 31, 0, Z_DATA_ERROR);
    inf("1f 8b 8 80", "bad gzip flags", 0, 31, 0, Z_DATA_ERROR);
    inf("77 85", "bad zlib method", 0, 15, 0, Z_DATA_ERROR);
    inf("8 99", "set window size from header", 0, 0, 0, Z_OK);
    inf("78 9c", "bad zlib window size", 0, 8, 0, Z_DATA_ERROR);
    inf("78 9c 63 0 0 0 1 0 1", "check adler32", 0, 15, 1, Z_STREAM_END);
    inf("1f 8b 8 1e 0 0 0 0 0 0 1 0 0 0 0 0 0", "bad header crc", 0, 47, 1,
        Z_DATA_ERROR);
    inf("1f 8b 8 2 0 0 0 0 0 0 1d 26 3 0 0 0 0 0 0 0 0 0", "check gzip length",
        0, 47, 0, Z_STREAM_END);
    inf("78 90", "bad zlib header check", 0, 47, 0, Z_DATA_ERROR);
    inf("8 b8 0 0 0 1", "need dictionary", 0, 8, 0, Z_NEED_DICT);
    inf("78 9c 63 0", "compute adler32", 0, 15, 1, Z_OK);

    mem_setup(&strm);
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit2(&strm, -8);
    strm.avail_in = 2;
    strm.next_in = (void *)"\x63";
    strm.avail_out = 1;
    strm.next_out = (void *)&ret;
    mem_limit(&strm, 1);
    ret = inflate(&strm, Z_NO_FLUSH);           assert(ret == Z_MEM_ERROR);
    ret = inflate(&strm, Z_NO_FLUSH);           assert(ret == Z_MEM_ERROR);
    mem_limit(&strm, 0);
    memset(dict, 0, 257);
    ret = inflateSetDictionary(&strm, dict, 257);
                                                assert(ret == Z_OK);
    mem_limit(&strm, (sizeof(struct inflate_state) << 1) + 256);
    ret = inflatePrime(&strm, 16, 0);           assert(ret == Z_OK);
    strm.avail_in = 2;
    strm.next_in = (void *)"\x80";
    ret = inflateSync(&strm);                   assert(ret == Z_DATA_ERROR);
    ret = inflate(&strm, Z_NO_FLUSH);           assert(ret == Z_STREAM_ERROR);
    strm.avail_in = 4;
    strm.next_in = (void *)"\0\0\xff\xff";
    ret = inflateSync(&strm);                   assert(ret == Z_OK);
    (void)inflateSyncPoint(&strm);
    ret = inflateCopy(&copy, &strm);            assert(ret == Z_MEM_ERROR);
    mem_limit(&strm, 0);
    ret = inflateUndermine(&strm, 1);           assert(ret == Z_DATA_ERROR);
    (void)inflateMark(&strm);
    ret = inflateEnd(&strm);                    assert(ret == Z_OK);
    mem_done(&strm, "miscellaneous, force memory errors");
}

/* input and output functions for inflateBack() */
local unsigned pull(void *desc, unsigned char **buf)
{
    static unsigned int next = 0;
    static unsigned char dat[] = {0x63, 0, 2, 0};
    struct inflate_state *state;

    if (desc == Z_NULL) {
        next = 0;
        return 0;   /* no input (already provided at next_in) */
    }
    state = (void *)((z_stream *)desc)->state;
    if (state != Z_NULL)
        state->mode = SYNC;     /* force an otherwise impossible situation */
    return next < sizeof(dat) ? (*buf = dat + next++, 1) : 0;
}

local int push(void *desc, unsigned char *buf, unsigned len)
{
    buf += len;
    return desc != Z_NULL;      /* force error if desc not null */
}

/* cover inflateBack() up to common deflate data cases and after those */
local void cover_back(void)
{
    int ret;
    z_stream strm;
    unsigned char win[32768];

    ret = inflateBackInit_(Z_NULL, 0, win, 0, 0);
                                                assert(ret == Z_VERSION_ERROR);
    ret = inflateBackInit(Z_NULL, 0, win);      assert(ret == Z_STREAM_ERROR);
    ret = inflateBack(Z_NULL, Z_NULL, Z_NULL, Z_NULL, Z_NULL);
                                                assert(ret == Z_STREAM_ERROR);
    ret = inflateBackEnd(Z_NULL);               assert(ret == Z_STREAM_ERROR);
    fputs("inflateBack bad parameters\n", stderr);

    mem_setup(&strm);
    ret = inflateBackInit(&strm, 15, win);      assert(ret == Z_OK);
    strm.avail_in = 2;
    strm.next_in = (void *)"\x03";
    ret = inflateBack(&strm, pull, Z_NULL, push, Z_NULL);
                                                assert(ret == Z_STREAM_END);
        /* force output error */
    strm.avail_in = 3;
    strm.next_in = (void *)"\x63\x00";
    ret = inflateBack(&strm, pull, Z_NULL, push, &strm);
                                                assert(ret == Z_BUF_ERROR);
        /* force mode error by mucking with state */
    ret = inflateBack(&strm, pull, &strm, push, Z_NULL);
                                                assert(ret == Z_STREAM_ERROR);
    ret = inflateBackEnd(&strm);                assert(ret == Z_OK);
    mem_done(&strm, "inflateBack bad state");

    ret = inflateBackInit(&strm, 15, win);      assert(ret == Z_OK);
    ret = inflateBackEnd(&strm);                assert(ret == Z_OK);
    fputs("inflateBack built-in memory routines\n", stderr);
}

/* do a raw inflate of data in hexadecimal with both inflate and inflateBack */
local int try(char *hex, char *id, int err)
{
    int ret;
    unsigned len, size;
    unsigned char *in, *out, *win;
    char *prefix;
    z_stream strm;

    /* convert to hex */
    in = h2b(hex, &len);
    assert(in != NULL);

    /* allocate work areas */
    size = len << 3;
    out = malloc(size);
    assert(out != NULL);
    win = malloc(32768);
    assert(win != NULL);
    prefix = malloc(strlen(id) + 6);
    assert(prefix != NULL);

    /* first with inflate */
    strcpy(prefix, id);
    strcat(prefix, "-late");
    mem_setup(&strm);
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit2(&strm, err < 0 ? 47 : -15);
    assert(ret == Z_OK);
    strm.avail_in = len;
    strm.next_in = in;
    do {
        strm.avail_out = size;
        strm.next_out = out;
        ret = inflate(&strm, Z_TREES);
        assert(ret != Z_STREAM_ERROR && ret != Z_MEM_ERROR);
        if (ret == Z_DATA_ERROR || ret == Z_NEED_DICT)
            break;
    } while (strm.avail_in || strm.avail_out == 0);
    if (err) {
        assert(ret == Z_DATA_ERROR);
        assert(strcmp(id, strm.msg) == 0);
    }
    inflateEnd(&strm);
    mem_done(&strm, prefix);

    /* then with inflateBack */
    if (err >= 0) {
        strcpy(prefix, id);
        strcat(prefix, "-back");
        mem_setup(&strm);
        ret = inflateBackInit(&strm, 15, win);
        assert(ret == Z_OK);
        strm.avail_in = len;
        strm.next_in = in;
        ret = inflateBack(&strm, pull, Z_NULL, push, Z_NULL);
        assert(ret != Z_STREAM_ERROR);
        if (err) {
            assert(ret == Z_DATA_ERROR);
            assert(strcmp(id, strm.msg) == 0);
        }
        inflateBackEnd(&strm);
        mem_done(&strm, prefix);
    }

    /* clean up */
    free(prefix);
    free(win);
    free(out);
    free(in);
    return ret;
}

/* cover deflate data cases in both inflate() and inflateBack() */
local void cover_inflate(void)
{
    try("0 0 0 0 0", "invalid stored block lengths", 1);
    try("3 0", "fixed", 0);
    try("6", "invalid block type", 1);
    try("1 1 0 fe ff 0", "stored", 0);
    try("fc 0 0", "too many length or distance symbols", 1);
    try("4 0 fe ff", "invalid code lengths set", 1);
    try("4 0 24 49 0", "invalid bit length repeat", 1);
    try("4 0 24 e9 ff ff", "invalid bit length repeat", 1);
    try("4 0 24 e9 ff 6d", "invalid code -- missing end-of-block", 1);
    try("4 80 49 92 24 49 92 24 71 ff ff 93 11 0",
        "invalid literal/lengths set", 1);
    try("4 80 49 92 24 49 92 24 f b4 ff ff c3 84", "invalid distances set", 1);
    try("4 c0 81 8 0 0 0 0 20 7f eb b 0 0", "invalid literal/length code", 1);
    try("2 7e ff ff", "invalid distance code", 1);
    try("c c0 81 0 0 0 0 0 90 ff 6b 4 0", "invalid distance too far back", 1);

    /* also trailer mismatch just in inflate() */
    try("1f 8b 8 0 0 0 0 0 0 0 3 0 0 0 0 1", "incorrect data check", -1);
    try("1f 8b 8 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 1",
        "incorrect length check", -1);
    try("5 c0 21 d 0 0 0 80 b0 fe 6d 2f 91 6c", "pull 17", 0);
    try("5 e0 81 91 24 cb b2 2c 49 e2 f 2e 8b 9a 47 56 9f fb fe ec d2 ff 1f",
        "long code", 0);
    try("ed c0 1 1 0 0 0 40 20 ff 57 1b 42 2c 4f", "length extra", 0);
    try("ed cf c1 b1 2c 47 10 c4 30 fa 6f 35 1d 1 82 59 3d fb be 2e 2a fc f c",
        "long distance and extra", 0);
    try("ed c0 81 0 0 0 0 80 a0 fd a9 17 a9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 "
        "0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6", "window end", 0);
    inf("2 8 20 80 0 3 0", "inflate_fast TYPE return", 0, -15, 258,
        Z_STREAM_END);
    inf("63 18 5 40 c 0", "window wrap", 3, -8, 300, Z_OK);
}

/* cover remaining lines in inftrees.c */
local void cover_trees(void)
{
    int ret;
    unsigned bits;
    unsigned short lens[16], work[16];
    code *next, table[ENOUGH_DISTS];

    /* we need to call inflate_table() directly in order to manifest not-
       enough errors, since zlib insures that enough is always enough */
    for (bits = 0; bits < 15; bits++)
        lens[bits] = (unsigned short)(bits + 1);
    lens[15] = 15;
    next = table;
    bits = 15;
    ret = inflate_table(DISTS, lens, 16, &next, &bits, work);
                                                assert(ret == 1);
    next = table;
    bits = 1;
    ret = inflate_table(DISTS, lens, 16, &next, &bits, work);
                                                assert(ret == 1);
    fputs("inflate_table not enough errors\n", stderr);
}

/* cover remaining inffast.c decoding and window copying */
local void cover_fast(void)
{
    inf("e5 e0 81 ad 6d cb b2 2c c9 01 1e 59 63 ae 7d ee fb 4d fd b5 35 41 68"
        " ff 7f 0f 0 0 0", "fast length extra bits", 0, -8, 258, Z_DATA_ERROR);
    inf("25 fd 81 b5 6d 59 b6 6a 49 ea af 35 6 34 eb 8c b9 f6 b9 1e ef 67 49"
        " 50 fe ff ff 3f 0 0", "fast distance extra bits", 0, -8, 258,
        Z_DATA_ERROR);
    inf("3 7e 0 0 0 0 0", "fast invalid distance code", 0, -8, 258,
        Z_DATA_ERROR);
    inf("1b 7 0 0 0 0 0", "fast invalid literal/length code", 0, -8, 258,
        Z_DATA_ERROR);
    inf("d c7 1 ae eb 38 c 4 41 a0 87 72 de df fb 1f b8 36 b1 38 5d ff ff 0",
        "fast 2nd level codes and too far back", 0, -8, 258, Z_DATA_ERROR);
    inf("63 18 5 8c 10 8 0 0 0 0", "very common case", 0, -8, 259, Z_OK);
    inf("63 60 60 18 c9 0 8 18 18 18 26 c0 28 0 29 0 0 0",
        "contiguous and wrap around window", 6, -8, 259, Z_OK);
    inf("63 0 3 0 0 0 0 0", "copy direct from output", 0, -8, 259,
        Z_STREAM_END);
}

int main(void)
{
    fprintf(stderr, "%s\n", zlibVersion());
    cover_support();
    cover_wrap();
    cover_back();
    cover_inflate();
    cover_trees();
    cover_fast();
    return 0;
}