summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_tarfile.py
blob: 817e6f17997121520657608c33e6d217d64904b2 (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
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
import sys
import os
import io
from hashlib import sha256
from contextlib import contextmanager
from random import Random
import pathlib

import unittest
import unittest.mock
import tarfile

from test import support
from test.support import os_helper
from test.support import script_helper

# Check for our compression modules.
try:
    import gzip
except ImportError:
    gzip = None
try:
    import bz2
except ImportError:
    bz2 = None
try:
    import lzma
except ImportError:
    lzma = None

def sha256sum(data):
    return sha256(data).hexdigest()

TEMPDIR = os.path.abspath(os_helper.TESTFN) + "-tardir"
tarextdir = TEMPDIR + '-extract-test'
tarname = support.findfile("testtar.tar")
gzipname = os.path.join(TEMPDIR, "testtar.tar.gz")
bz2name = os.path.join(TEMPDIR, "testtar.tar.bz2")
xzname = os.path.join(TEMPDIR, "testtar.tar.xz")
tmpname = os.path.join(TEMPDIR, "tmp.tar")
dotlessname = os.path.join(TEMPDIR, "testtar")

sha256_regtype = (
    "e09e4bc8b3c9d9177e77256353b36c159f5f040531bbd4b024a8f9b9196c71ce"
)
sha256_sparse = (
    "4f05a776071146756345ceee937b33fc5644f5a96b9780d1c7d6a32cdf164d7b"
)


class TarTest:
    tarname = tarname
    suffix = ''
    open = io.FileIO
    taropen = tarfile.TarFile.taropen

    @property
    def mode(self):
        return self.prefix + self.suffix

@support.requires_gzip()
class GzipTest:
    tarname = gzipname
    suffix = 'gz'
    open = gzip.GzipFile if gzip else None
    taropen = tarfile.TarFile.gzopen

@support.requires_bz2()
class Bz2Test:
    tarname = bz2name
    suffix = 'bz2'
    open = bz2.BZ2File if bz2 else None
    taropen = tarfile.TarFile.bz2open

@support.requires_lzma()
class LzmaTest:
    tarname = xzname
    suffix = 'xz'
    open = lzma.LZMAFile if lzma else None
    taropen = tarfile.TarFile.xzopen


class ReadTest(TarTest):

    prefix = "r:"

    def setUp(self):
        self.tar = tarfile.open(self.tarname, mode=self.mode,
                                encoding="iso8859-1")

    def tearDown(self):
        self.tar.close()


class UstarReadTest(ReadTest, unittest.TestCase):

    def test_fileobj_regular_file(self):
        tarinfo = self.tar.getmember("ustar/regtype")
        with self.tar.extractfile(tarinfo) as fobj:
            data = fobj.read()
            self.assertEqual(len(data), tarinfo.size,
                    "regular file extraction failed")
            self.assertEqual(sha256sum(data), sha256_regtype,
                    "regular file extraction failed")

    def test_fileobj_readlines(self):
        self.tar.extract("ustar/regtype", TEMPDIR)
        tarinfo = self.tar.getmember("ustar/regtype")
        with open(os.path.join(TEMPDIR, "ustar/regtype"), "r") as fobj1:
            lines1 = fobj1.readlines()

        with self.tar.extractfile(tarinfo) as fobj:
            fobj2 = io.TextIOWrapper(fobj)
            lines2 = fobj2.readlines()
            self.assertEqual(lines1, lines2,
                    "fileobj.readlines() failed")
            self.assertEqual(len(lines2), 114,
                    "fileobj.readlines() failed")
            self.assertEqual(lines2[83],
                    "I will gladly admit that Python is not the fastest "
                    "running scripting language.\n",
                    "fileobj.readlines() failed")

    def test_fileobj_iter(self):
        self.tar.extract("ustar/regtype", TEMPDIR)
        tarinfo = self.tar.getmember("ustar/regtype")
        with open(os.path.join(TEMPDIR, "ustar/regtype"), "r") as fobj1:
            lines1 = fobj1.readlines()
        with self.tar.extractfile(tarinfo) as fobj2:
            lines2 = list(io.TextIOWrapper(fobj2))
            self.assertEqual(lines1, lines2,
                    "fileobj.__iter__() failed")

    def test_fileobj_seek(self):
        self.tar.extract("ustar/regtype", TEMPDIR)
        with open(os.path.join(TEMPDIR, "ustar/regtype"), "rb") as fobj:
            data = fobj.read()

        tarinfo = self.tar.getmember("ustar/regtype")
        with self.tar.extractfile(tarinfo) as fobj:
            text = fobj.read()
            fobj.seek(0)
            self.assertEqual(0, fobj.tell(),
                         "seek() to file's start failed")
            fobj.seek(2048, 0)
            self.assertEqual(2048, fobj.tell(),
                         "seek() to absolute position failed")
            fobj.seek(-1024, 1)
            self.assertEqual(1024, fobj.tell(),
                         "seek() to negative relative position failed")
            fobj.seek(1024, 1)
            self.assertEqual(2048, fobj.tell(),
                         "seek() to positive relative position failed")
            s = fobj.read(10)
            self.assertEqual(s, data[2048:2058],
                         "read() after seek failed")
            fobj.seek(0, 2)
            self.assertEqual(tarinfo.size, fobj.tell(),
                         "seek() to file's end failed")
            self.assertEqual(fobj.read(), b"",
                         "read() at file's end did not return empty string")
            fobj.seek(-tarinfo.size, 2)
            self.assertEqual(0, fobj.tell(),
                         "relative seek() to file's end failed")
            fobj.seek(512)
            s1 = fobj.readlines()
            fobj.seek(512)
            s2 = fobj.readlines()
            self.assertEqual(s1, s2,
                         "readlines() after seek failed")
            fobj.seek(0)
            self.assertEqual(len(fobj.readline()), fobj.tell(),
                         "tell() after readline() failed")
            fobj.seek(512)
            self.assertEqual(len(fobj.readline()) + 512, fobj.tell(),
                         "tell() after seek() and readline() failed")
            fobj.seek(0)
            line = fobj.readline()
            self.assertEqual(fobj.read(), data[len(line):],
                         "read() after readline() failed")

    def test_fileobj_text(self):
        with self.tar.extractfile("ustar/regtype") as fobj:
            fobj = io.TextIOWrapper(fobj)
            data = fobj.read().encode("iso8859-1")
            self.assertEqual(sha256sum(data), sha256_regtype)
            try:
                fobj.seek(100)
            except AttributeError:
                # Issue #13815: seek() complained about a missing
                # flush() method.
                self.fail("seeking failed in text mode")

    # Test if symbolic and hard links are resolved by extractfile().  The
    # test link members each point to a regular member whose data is
    # supposed to be exported.
    def _test_fileobj_link(self, lnktype, regtype):
        with self.tar.extractfile(lnktype) as a, \
             self.tar.extractfile(regtype) as b:
            self.assertEqual(a.name, b.name)

    def test_fileobj_link1(self):
        self._test_fileobj_link("ustar/lnktype", "ustar/regtype")

    def test_fileobj_link2(self):
        self._test_fileobj_link("./ustar/linktest2/lnktype",
                                "ustar/linktest1/regtype")

    def test_fileobj_symlink1(self):
        self._test_fileobj_link("ustar/symtype", "ustar/regtype")

    def test_fileobj_symlink2(self):
        self._test_fileobj_link("./ustar/linktest2/symtype",
                                "ustar/linktest1/regtype")

    def test_issue14160(self):
        self._test_fileobj_link("symtype2", "ustar/regtype")

class GzipUstarReadTest(GzipTest, UstarReadTest):
    pass

class Bz2UstarReadTest(Bz2Test, UstarReadTest):
    pass

class LzmaUstarReadTest(LzmaTest, UstarReadTest):
    pass


class ListTest(ReadTest, unittest.TestCase):

    # Override setUp to use default encoding (UTF-8)
    def setUp(self):
        self.tar = tarfile.open(self.tarname, mode=self.mode)

    def test_list(self):
        tio = io.TextIOWrapper(io.BytesIO(), 'ascii', newline='\n')
        with support.swap_attr(sys, 'stdout', tio):
            self.tar.list(verbose=False)
        out = tio.detach().getvalue()
        self.assertIn(b'ustar/conttype', out)
        self.assertIn(b'ustar/regtype', out)
        self.assertIn(b'ustar/lnktype', out)
        self.assertIn(b'ustar' + (b'/12345' * 40) + b'67/longname', out)
        self.assertIn(b'./ustar/linktest2/symtype', out)
        self.assertIn(b'./ustar/linktest2/lnktype', out)
        # Make sure it puts trailing slash for directory
        self.assertIn(b'ustar/dirtype/', out)
        self.assertIn(b'ustar/dirtype-with-size/', out)
        # Make sure it is able to print unencodable characters
        def conv(b):
            s = b.decode(self.tar.encoding, 'surrogateescape')
            return s.encode('ascii', 'backslashreplace')
        self.assertIn(conv(b'ustar/umlauts-\xc4\xd6\xdc\xe4\xf6\xfc\xdf'), out)
        self.assertIn(conv(b'misc/regtype-hpux-signed-chksum-'
                           b'\xc4\xd6\xdc\xe4\xf6\xfc\xdf'), out)
        self.assertIn(conv(b'misc/regtype-old-v7-signed-chksum-'
                           b'\xc4\xd6\xdc\xe4\xf6\xfc\xdf'), out)
        self.assertIn(conv(b'pax/bad-pax-\xe4\xf6\xfc'), out)
        self.assertIn(conv(b'pax/hdrcharset-\xe4\xf6\xfc'), out)
        # Make sure it prints files separated by one newline without any
        # 'ls -l'-like accessories if verbose flag is not being used
        # ...
        # ustar/conttype
        # ustar/regtype
        # ...
        self.assertRegex(out, br'ustar/conttype ?\r?\n'
                              br'ustar/regtype ?\r?\n')
        # Make sure it does not print the source of link without verbose flag
        self.assertNotIn(b'link to', out)
        self.assertNotIn(b'->', out)

    def test_list_verbose(self):
        tio = io.TextIOWrapper(io.BytesIO(), 'ascii', newline='\n')
        with support.swap_attr(sys, 'stdout', tio):
            self.tar.list(verbose=True)
        out = tio.detach().getvalue()
        # Make sure it prints files separated by one newline with 'ls -l'-like
        # accessories if verbose flag is being used
        # ...
        # ?rw-r--r-- tarfile/tarfile     7011 2003-01-06 07:19:43 ustar/conttype
        # ?rw-r--r-- tarfile/tarfile     7011 2003-01-06 07:19:43 ustar/regtype
        # ...
        self.assertRegex(out, (br'\?rw-r--r-- tarfile/tarfile\s+7011 '
                               br'\d{4}-\d\d-\d\d\s+\d\d:\d\d:\d\d '
                               br'ustar/\w+type ?\r?\n') * 2)
        # Make sure it prints the source of link with verbose flag
        self.assertIn(b'ustar/symtype -> regtype', out)
        self.assertIn(b'./ustar/linktest2/symtype -> ../linktest1/regtype', out)
        self.assertIn(b'./ustar/linktest2/lnktype link to '
                      b'./ustar/linktest1/regtype', out)
        self.assertIn(b'gnu' + (b'/123' * 125) + b'/longlink link to gnu' +
                      (b'/123' * 125) + b'/longname', out)
        self.assertIn(b'pax' + (b'/123' * 125) + b'/longlink link to pax' +
                      (b'/123' * 125) + b'/longname', out)

    def test_list_members(self):
        tio = io.TextIOWrapper(io.BytesIO(), 'ascii', newline='\n')
        def members(tar):
            for tarinfo in tar.getmembers():
                if 'reg' in tarinfo.name:
                    yield tarinfo
        with support.swap_attr(sys, 'stdout', tio):
            self.tar.list(verbose=False, members=members(self.tar))
        out = tio.detach().getvalue()
        self.assertIn(b'ustar/regtype', out)
        self.assertNotIn(b'ustar/conttype', out)


class GzipListTest(GzipTest, ListTest):
    pass


class Bz2ListTest(Bz2Test, ListTest):
    pass


class LzmaListTest(LzmaTest, ListTest):
    pass


class CommonReadTest(ReadTest):

    def test_is_tarfile_erroneous(self):
        with open(tmpname, "wb"):
            pass

        # is_tarfile works on filenames
        self.assertFalse(tarfile.is_tarfile(tmpname))

        # is_tarfile works on path-like objects
        self.assertFalse(tarfile.is_tarfile(pathlib.Path(tmpname)))

        # is_tarfile works on file objects
        with open(tmpname, "rb") as fobj:
            self.assertFalse(tarfile.is_tarfile(fobj))

        # is_tarfile works on file-like objects
        self.assertFalse(tarfile.is_tarfile(io.BytesIO(b"invalid")))

    def test_is_tarfile_valid(self):
        # is_tarfile works on filenames
        self.assertTrue(tarfile.is_tarfile(self.tarname))

        # is_tarfile works on path-like objects
        self.assertTrue(tarfile.is_tarfile(pathlib.Path(self.tarname)))

        # is_tarfile works on file objects
        with open(self.tarname, "rb") as fobj:
            self.assertTrue(tarfile.is_tarfile(fobj))

        # is_tarfile works on file-like objects
        with open(self.tarname, "rb") as fobj:
            self.assertTrue(tarfile.is_tarfile(io.BytesIO(fobj.read())))

    def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

    def test_non_existent_tarfile(self):
        # Test for issue11513: prevent non-existent gzipped tarfiles raising
        # multiple exceptions.
        with self.assertRaisesRegex(FileNotFoundError, "xxx"):
            tarfile.open("xxx", self.mode)

    def test_null_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test guarantees that tarfile.open() does not treat an empty
        # file as an empty tar archive.
        with open(tmpname, "wb"):
            pass
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, self.mode)
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname)

    def test_ignore_zeros(self):
        # Test TarFile's ignore_zeros option.
        # generate 512 pseudorandom bytes
        data = Random(0).randbytes(512)
        for char in (b'\0', b'a'):
            # Test if EOFHeaderError ('\0') and InvalidHeaderError ('a')
            # are ignored correctly.
            with self.open(tmpname, "w") as fobj:
                fobj.write(char * 1024)
                tarinfo = tarfile.TarInfo("foo")
                tarinfo.size = len(data)
                fobj.write(tarinfo.tobuf())
                fobj.write(data)

            tar = tarfile.open(tmpname, mode="r", ignore_zeros=True)
            try:
                self.assertListEqual(tar.getnames(), ["foo"],
                    "ignore_zeros=True should have skipped the %r-blocks" %
                    char)
            finally:
                tar.close()

    def test_premature_end_of_archive(self):
        for size in (512, 600, 1024, 1200):
            with tarfile.open(tmpname, "w:") as tar:
                t = tarfile.TarInfo("foo")
                t.size = 1024
                tar.addfile(t, io.BytesIO(b"a" * 1024))

            with open(tmpname, "r+b") as fobj:
                fobj.truncate(size)

            with tarfile.open(tmpname) as tar:
                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    for t in tar:
                        pass

            with tarfile.open(tmpname) as tar:
                t = tar.next()

                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    tar.extract(t, TEMPDIR)

                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    tar.extractfile(t).read()

    def test_length_zero_header(self):
        # bpo-39017 (CVE-2019-20907): reading a zero-length header should fail
        # with an exception
        with self.assertRaisesRegex(tarfile.ReadError, "file could not be opened successfully"):
            with tarfile.open(support.findfile('recursion.tar')) as tar:
                pass

class MiscReadTestBase(CommonReadTest):
    def requires_name_attribute(self):
        pass

    def test_no_name_argument(self):
        self.requires_name_attribute()
        with open(self.tarname, "rb") as fobj:
            self.assertIsInstance(fobj.name, str)
            with tarfile.open(fileobj=fobj, mode=self.mode) as tar:
                self.assertIsInstance(tar.name, str)
                self.assertEqual(tar.name, os.path.abspath(fobj.name))

    def test_no_name_attribute(self):
        with open(self.tarname, "rb") as fobj:
            data = fobj.read()
        fobj = io.BytesIO(data)
        self.assertRaises(AttributeError, getattr, fobj, "name")
        tar = tarfile.open(fileobj=fobj, mode=self.mode)
        self.assertIsNone(tar.name)

    def test_empty_name_attribute(self):
        with open(self.tarname, "rb") as fobj:
            data = fobj.read()
        fobj = io.BytesIO(data)
        fobj.name = ""
        with tarfile.open(fileobj=fobj, mode=self.mode) as tar:
            self.assertIsNone(tar.name)

    def test_int_name_attribute(self):
        # Issue 21044: tarfile.open() should handle fileobj with an integer
        # 'name' attribute.
        fd = os.open(self.tarname, os.O_RDONLY)
        with open(fd, 'rb') as fobj:
            self.assertIsInstance(fobj.name, int)
            with tarfile.open(fileobj=fobj, mode=self.mode) as tar:
                self.assertIsNone(tar.name)

    def test_bytes_name_attribute(self):
        self.requires_name_attribute()
        tarname = os.fsencode(self.tarname)
        with open(tarname, 'rb') as fobj:
            self.assertIsInstance(fobj.name, bytes)
            with tarfile.open(fileobj=fobj, mode=self.mode) as tar:
                self.assertIsInstance(tar.name, bytes)
                self.assertEqual(tar.name, os.path.abspath(fobj.name))

    def test_pathlike_name(self):
        tarname = pathlib.Path(self.tarname)
        with tarfile.open(tarname, mode=self.mode) as tar:
            self.assertIsInstance(tar.name, str)
            self.assertEqual(tar.name, os.path.abspath(os.fspath(tarname)))
        with self.taropen(tarname) as tar:
            self.assertIsInstance(tar.name, str)
            self.assertEqual(tar.name, os.path.abspath(os.fspath(tarname)))
        with tarfile.TarFile.open(tarname, mode=self.mode) as tar:
            self.assertIsInstance(tar.name, str)
            self.assertEqual(tar.name, os.path.abspath(os.fspath(tarname)))
        if self.suffix == '':
            with tarfile.TarFile(tarname, mode='r') as tar:
                self.assertIsInstance(tar.name, str)
                self.assertEqual(tar.name, os.path.abspath(os.fspath(tarname)))

    def test_illegal_mode_arg(self):
        with open(tmpname, 'wb'):
            pass
        with self.assertRaisesRegex(ValueError, 'mode must be '):
            tar = self.taropen(tmpname, 'q')
        with self.assertRaisesRegex(ValueError, 'mode must be '):
            tar = self.taropen(tmpname, 'rw')
        with self.assertRaisesRegex(ValueError, 'mode must be '):
            tar = self.taropen(tmpname, '')

    def test_fileobj_with_offset(self):
        # Skip the first member and store values from the second member
        # of the testtar.
        tar = tarfile.open(self.tarname, mode=self.mode)
        try:
            tar.next()
            t = tar.next()
            name = t.name
            offset = t.offset
            with tar.extractfile(t) as f:
                data = f.read()
        finally:
            tar.close()

        # Open the testtar and seek to the offset of the second member.
        with self.open(self.tarname) as fobj:
            fobj.seek(offset)

            # Test if the tarfile starts with the second member.
            with tar.open(self.tarname, mode="r:", fileobj=fobj) as tar:
                t = tar.next()
                self.assertEqual(t.name, name)
                # Read to the end of fileobj and test if seeking back to the
                # beginning works.
                tar.getmembers()
                self.assertEqual(tar.extractfile(t).read(), data,
                        "seek back did not work")

    def test_fail_comp(self):
        # For Gzip and Bz2 Tests: fail with a ReadError on an uncompressed file.
        self.assertRaises(tarfile.ReadError, tarfile.open, tarname, self.mode)
        with open(tarname, "rb") as fobj:
            self.assertRaises(tarfile.ReadError, tarfile.open,
                              fileobj=fobj, mode=self.mode)

    def test_v7_dirtype(self):
        # Test old style dirtype member (bug #1336623):
        # Old V7 tars create directory members using an AREGTYPE
        # header with a "/" appended to the filename field.
        tarinfo = self.tar.getmember("misc/dirtype-old-v7")
        self.assertEqual(tarinfo.type, tarfile.DIRTYPE,
                "v7 dirtype failed")

    def test_xstar_type(self):
        # The xstar format stores extra atime and ctime fields inside the
        # space reserved for the prefix field. The prefix field must be
        # ignored in this case, otherwise it will mess up the name.
        try:
            self.tar.getmember("misc/regtype-xstar")
        except KeyError:
            self.fail("failed to find misc/regtype-xstar (mangled prefix?)")

    def test_check_members(self):
        for tarinfo in self.tar:
            self.assertEqual(int(tarinfo.mtime), 0o7606136617,
                    "wrong mtime for %s" % tarinfo.name)
            if not tarinfo.name.startswith("ustar/"):
                continue
            self.assertEqual(tarinfo.uname, "tarfile",
                    "wrong uname for %s" % tarinfo.name)

    def test_find_members(self):
        self.assertEqual(self.tar.getmembers()[-1].name, "misc/eof",
                "could not find all members")

    @unittest.skipUnless(hasattr(os, "link"),
                         "Missing hardlink implementation")
    @os_helper.skip_unless_symlink
    def test_extract_hardlink(self):
        # Test hardlink extraction (e.g. bug #857297).
        with tarfile.open(tarname, errorlevel=1, encoding="iso8859-1") as tar:
            tar.extract("ustar/regtype", TEMPDIR)
            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/regtype"))

            tar.extract("ustar/lnktype", TEMPDIR)
            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/lnktype"))
            with open(os.path.join(TEMPDIR, "ustar/lnktype"), "rb") as f:
                data = f.read()
            self.assertEqual(sha256sum(data), sha256_regtype)

            tar.extract("ustar/symtype", TEMPDIR)
            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/symtype"))
            with open(os.path.join(TEMPDIR, "ustar/symtype"), "rb") as f:
                data = f.read()
            self.assertEqual(sha256sum(data), sha256_regtype)

    def test_extractall(self):
        # Test if extractall() correctly restores directory permissions
        # and times (see issue1735).
        tar = tarfile.open(tarname, encoding="iso8859-1")
        DIR = os.path.join(TEMPDIR, "extractall")
        os.mkdir(DIR)
        try:
            directories = [t for t in tar if t.isdir()]
            tar.extractall(DIR, directories)
            for tarinfo in directories:
                path = os.path.join(DIR, tarinfo.name)
                if sys.platform != "win32":
                    # Win32 has no support for fine grained permissions.
                    self.assertEqual(tarinfo.mode & 0o777,
                                     os.stat(path).st_mode & 0o777)
                def format_mtime(mtime):
                    if isinstance(mtime, float):
                        return "{} ({})".format(mtime, mtime.hex())
                    else:
                        return "{!r} (int)".format(mtime)
                file_mtime = os.path.getmtime(path)
                errmsg = "tar mtime {0} != file time {1} of path {2!a}".format(
                    format_mtime(tarinfo.mtime),
                    format_mtime(file_mtime),
                    path)
                self.assertEqual(tarinfo.mtime, file_mtime, errmsg)
        finally:
            tar.close()
            os_helper.rmtree(DIR)

    def test_extract_directory(self):
        dirtype = "ustar/dirtype"
        DIR = os.path.join(TEMPDIR, "extractdir")
        os.mkdir(DIR)
        try:
            with tarfile.open(tarname, encoding="iso8859-1") as tar:
                tarinfo = tar.getmember(dirtype)
                tar.extract(tarinfo, path=DIR)
                extracted = os.path.join(DIR, dirtype)
                self.assertEqual(os.path.getmtime(extracted), tarinfo.mtime)
                if sys.platform != "win32":
                    self.assertEqual(os.stat(extracted).st_mode & 0o777, 0o755)
        finally:
            os_helper.rmtree(DIR)

    def test_extractall_pathlike_name(self):
        DIR = pathlib.Path(TEMPDIR) / "extractall"
        with os_helper.temp_dir(DIR), \
             tarfile.open(tarname, encoding="iso8859-1") as tar:
            directories = [t for t in tar if t.isdir()]
            tar.extractall(DIR, directories)
            for tarinfo in directories:
                path = DIR / tarinfo.name
                self.assertEqual(os.path.getmtime(path), tarinfo.mtime)

    def test_extract_pathlike_name(self):
        dirtype = "ustar/dirtype"
        DIR = pathlib.Path(TEMPDIR) / "extractall"
        with os_helper.temp_dir(DIR), \
             tarfile.open(tarname, encoding="iso8859-1") as tar:
            tarinfo = tar.getmember(dirtype)
            tar.extract(tarinfo, path=DIR)
            extracted = DIR / dirtype
            self.assertEqual(os.path.getmtime(extracted), tarinfo.mtime)

    def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            os_helper.unlink(empty)

    def test_parallel_iteration(self):
        # Issue #16601: Restarting iteration over tarfile continued
        # from where it left off.
        with tarfile.open(self.tarname) as tar:
            for m1, m2 in zip(tar, tar):
                self.assertEqual(m1.offset, m2.offset)
                self.assertEqual(m1.get_info(), m2.get_info())

class MiscReadTest(MiscReadTestBase, unittest.TestCase):
    test_fail_comp = None

class GzipMiscReadTest(GzipTest, MiscReadTestBase, unittest.TestCase):
    pass

class Bz2MiscReadTest(Bz2Test, MiscReadTestBase, unittest.TestCase):
    def requires_name_attribute(self):
        self.skipTest("BZ2File have no name attribute")

class LzmaMiscReadTest(LzmaTest, MiscReadTestBase, unittest.TestCase):
    def requires_name_attribute(self):
        self.skipTest("LZMAFile have no name attribute")


class StreamReadTest(CommonReadTest, unittest.TestCase):

    prefix="r|"

    def test_read_through(self):
        # Issue #11224: A poorly designed _FileInFile.read() method
        # caused seeking errors with stream tar files.
        for tarinfo in self.tar:
            if not tarinfo.isreg():
                continue
            with self.tar.extractfile(tarinfo) as fobj:
                while True:
                    try:
                        buf = fobj.read(512)
                    except tarfile.StreamError:
                        self.fail("simple read-through using "
                                  "TarFile.extractfile() failed")
                    if not buf:
                        break

    def test_fileobj_regular_file(self):
        tarinfo = self.tar.next() # get "regtype" (can't use getmember)
        with self.tar.extractfile(tarinfo) as fobj:
            data = fobj.read()
        self.assertEqual(len(data), tarinfo.size,
                "regular file extraction failed")
        self.assertEqual(sha256sum(data), sha256_regtype,
                "regular file extraction failed")

    def test_provoke_stream_error(self):
        tarinfos = self.tar.getmembers()
        with self.tar.extractfile(tarinfos[0]) as f: # read the first member
            self.assertRaises(tarfile.StreamError, f.read)

    def test_compare_members(self):
        tar1 = tarfile.open(tarname, encoding="iso8859-1")
        try:
            tar2 = self.tar

            while True:
                t1 = tar1.next()
                t2 = tar2.next()
                if t1 is None:
                    break
                self.assertIsNotNone(t2, "stream.next() failed.")

                if t2.islnk() or t2.issym():
                    with self.assertRaises(tarfile.StreamError):
                        tar2.extractfile(t2)
                    continue

                v1 = tar1.extractfile(t1)
                v2 = tar2.extractfile(t2)
                if v1 is None:
                    continue
                self.assertIsNotNone(v2, "stream.extractfile() failed")
                self.assertEqual(v1.read(), v2.read(),
                        "stream extraction failed")
        finally:
            tar1.close()

class GzipStreamReadTest(GzipTest, StreamReadTest):
    pass

class Bz2StreamReadTest(Bz2Test, StreamReadTest):
    pass

class LzmaStreamReadTest(LzmaTest, StreamReadTest):
    pass


class DetectReadTest(TarTest, unittest.TestCase):
    def _testfunc_file(self, name, mode):
        try:
            tar = tarfile.open(name, mode)
        except tarfile.ReadError as e:
            self.fail()
        else:
            tar.close()

    def _testfunc_fileobj(self, name, mode):
        try:
            with open(name, "rb") as f:
                tar = tarfile.open(name, mode, fileobj=f)
        except tarfile.ReadError as e:
            self.fail()
        else:
            tar.close()

    def _test_modes(self, testfunc):
        if self.suffix:
            with self.assertRaises(tarfile.ReadError):
                tarfile.open(tarname, mode="r:" + self.suffix)
            with self.assertRaises(tarfile.ReadError):
                tarfile.open(tarname, mode="r|" + self.suffix)
            with self.assertRaises(tarfile.ReadError):
                tarfile.open(self.tarname, mode="r:")
            with self.assertRaises(tarfile.ReadError):
                tarfile.open(self.tarname, mode="r|")
        testfunc(self.tarname, "r")
        testfunc(self.tarname, "r:" + self.suffix)
        testfunc(self.tarname, "r:*")
        testfunc(self.tarname, "r|" + self.suffix)
        testfunc(self.tarname, "r|*")

    def test_detect_file(self):
        self._test_modes(self._testfunc_file)

    def test_detect_fileobj(self):
        self._test_modes(self._testfunc_fileobj)

class GzipDetectReadTest(GzipTest, DetectReadTest):
    pass

class Bz2DetectReadTest(Bz2Test, DetectReadTest):
    def test_detect_stream_bz2(self):
        # Originally, tarfile's stream detection looked for the string
        # "BZh91" at the start of the file. This is incorrect because
        # the '9' represents the blocksize (900,000 bytes). If the file was
        # compressed using another blocksize autodetection fails.
        with open(tarname, "rb") as fobj:
            data = fobj.read()

        # Compress with blocksize 100,000 bytes, the file starts with "BZh11".
        with bz2.BZ2File(tmpname, "wb", compresslevel=1) as fobj:
            fobj.write(data)

        self._testfunc_file(tmpname, "r|*")

class LzmaDetectReadTest(LzmaTest, DetectReadTest):
    pass


class MemberReadTest(ReadTest, unittest.TestCase):

    def _test_member(self, tarinfo, chksum=None, **kwargs):
        if chksum is not None:
            with self.tar.extractfile(tarinfo) as f:
                self.assertEqual(sha256sum(f.read()), chksum,
                        "wrong sha256sum for %s" % tarinfo.name)

        kwargs["mtime"] = 0o7606136617
        kwargs["uid"] = 1000
        kwargs["gid"] = 100
        if "old-v7" not in tarinfo.name:
            # V7 tar can't handle alphabetic owners.
            kwargs["uname"] = "tarfile"
            kwargs["gname"] = "tarfile"
        for k, v in kwargs.items():
            self.assertEqual(getattr(tarinfo, k), v,
                    "wrong value in %s field of %s" % (k, tarinfo.name))

    def test_find_regtype(self):
        tarinfo = self.tar.getmember("ustar/regtype")
        self._test_member(tarinfo, size=7011, chksum=sha256_regtype)

    def test_find_conttype(self):
        tarinfo = self.tar.getmember("ustar/conttype")
        self._test_member(tarinfo, size=7011, chksum=sha256_regtype)

    def test_find_dirtype(self):
        tarinfo = self.tar.getmember("ustar/dirtype")
        self._test_member(tarinfo, size=0)

    def test_find_dirtype_with_size(self):
        tarinfo = self.tar.getmember("ustar/dirtype-with-size")
        self._test_member(tarinfo, size=255)

    def test_find_lnktype(self):
        tarinfo = self.tar.getmember("ustar/lnktype")
        self._test_member(tarinfo, size=0, linkname="ustar/regtype")

    def test_find_symtype(self):
        tarinfo = self.tar.getmember("ustar/symtype")
        self._test_member(tarinfo, size=0, linkname="regtype")

    def test_find_blktype(self):
        tarinfo = self.tar.getmember("ustar/blktype")
        self._test_member(tarinfo, size=0, devmajor=3, devminor=0)

    def test_find_chrtype(self):
        tarinfo = self.tar.getmember("ustar/chrtype")
        self._test_member(tarinfo, size=0, devmajor=1, devminor=3)

    def test_find_fifotype(self):
        tarinfo = self.tar.getmember("ustar/fifotype")
        self._test_member(tarinfo, size=0)

    def test_find_sparse(self):
        tarinfo = self.tar.getmember("ustar/sparse")
        self._test_member(tarinfo, size=86016, chksum=sha256_sparse)

    def test_find_gnusparse(self):
        tarinfo = self.tar.getmember("gnu/sparse")
        self._test_member(tarinfo, size=86016, chksum=sha256_sparse)

    def test_find_gnusparse_00(self):
        tarinfo = self.tar.getmember("gnu/sparse-0.0")
        self._test_member(tarinfo, size=86016, chksum=sha256_sparse)

    def test_find_gnusparse_01(self):
        tarinfo = self.tar.getmember("gnu/sparse-0.1")
        self._test_member(tarinfo, size=86016, chksum=sha256_sparse)

    def test_find_gnusparse_10(self):
        tarinfo = self.tar.getmember("gnu/sparse-1.0")
        self._test_member(tarinfo, size=86016, chksum=sha256_sparse)

    def test_find_umlauts(self):
        tarinfo = self.tar.getmember("ustar/umlauts-"
                                     "\xc4\xd6\xdc\xe4\xf6\xfc\xdf")
        self._test_member(tarinfo, size=7011, chksum=sha256_regtype)

    def test_find_ustar_longname(self):
        name = "ustar/" + "12345/" * 39 + "1234567/longname"
        self.assertIn(name, self.tar.getnames())

    def test_find_regtype_oldv7(self):
        tarinfo = self.tar.getmember("misc/regtype-old-v7")
        self._test_member(tarinfo, size=7011, chksum=sha256_regtype)

    def test_find_pax_umlauts(self):
        self.tar.close()
        self.tar = tarfile.open(self.tarname, mode=self.mode,
                                encoding="iso8859-1")
        tarinfo = self.tar.getmember("pax/umlauts-"
                                     "\xc4\xd6\xdc\xe4\xf6\xfc\xdf")
        self._test_member(tarinfo, size=7011, chksum=sha256_regtype)


class LongnameTest:

    def test_read_longname(self):
        # Test reading of longname (bug #1471427).
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        try:
            tarinfo = self.tar.getmember(longname)
        except KeyError:
            self.fail("longname not found")
        self.assertNotEqual(tarinfo.type, tarfile.DIRTYPE,
                "read longname as dirtype")

    def test_read_longlink(self):
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        longlink = self.subdir + "/" + "123/" * 125 + "longlink"
        try:
            tarinfo = self.tar.getmember(longlink)
        except KeyError:
            self.fail("longlink not found")
        self.assertEqual(tarinfo.linkname, longname, "linkname wrong")

    def test_truncated_longname(self):
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        tarinfo = self.tar.getmember(longname)
        offset = tarinfo.offset
        self.tar.fileobj.seek(offset)
        fobj = io.BytesIO(self.tar.fileobj.read(3 * 512))
        with self.assertRaises(tarfile.ReadError):
            tarfile.open(name="foo.tar", fileobj=fobj)

    def test_header_offset(self):
        # Test if the start offset of the TarInfo object includes
        # the preceding extended header.
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        offset = self.tar.getmember(longname).offset
        with open(tarname, "rb") as fobj:
            fobj.seek(offset)
            tarinfo = tarfile.TarInfo.frombuf(fobj.read(512),
                                              "iso8859-1", "strict")
            self.assertEqual(tarinfo.type, self.longnametype)


class GNUReadTest(LongnameTest, ReadTest, unittest.TestCase):

    subdir = "gnu"
    longnametype = tarfile.GNUTYPE_LONGNAME

    # Since 3.2 tarfile is supposed to accurately restore sparse members and
    # produce files with holes. This is what we actually want to test here.
    # Unfortunately, not all platforms/filesystems support sparse files, and
    # even on platforms that do it is non-trivial to make reliable assertions
    # about holes in files. Therefore, we first do one basic test which works
    # an all platforms, and after that a test that will work only on
    # platforms/filesystems that prove to support sparse files.
    def _test_sparse_file(self, name):
        self.tar.extract(name, TEMPDIR)
        filename = os.path.join(TEMPDIR, name)
        with open(filename, "rb") as fobj:
            data = fobj.read()
        self.assertEqual(sha256sum(data), sha256_sparse,
                "wrong sha256sum for %s" % name)

        if self._fs_supports_holes():
            s = os.stat(filename)
            self.assertLess(s.st_blocks * 512, s.st_size)

    def test_sparse_file_old(self):
        self._test_sparse_file("gnu/sparse")

    def test_sparse_file_00(self):
        self._test_sparse_file("gnu/sparse-0.0")

    def test_sparse_file_01(self):
        self._test_sparse_file("gnu/sparse-0.1")

    def test_sparse_file_10(self):
        self._test_sparse_file("gnu/sparse-1.0")

    @staticmethod
    def _fs_supports_holes():
        # Return True if the platform knows the st_blocks stat attribute and
        # uses st_blocks units of 512 bytes, and if the filesystem is able to
        # store holes of 4 KiB in files.
        #
        # The function returns False if page size is larger than 4 KiB.
        # For example, ppc64 uses pages of 64 KiB.
        if sys.platform.startswith("linux"):
            # Linux evidentially has 512 byte st_blocks units.
            name = os.path.join(TEMPDIR, "sparse-test")
            with open(name, "wb") as fobj:
                # Seek to "punch a hole" of 4 KiB
                fobj.seek(4096)
                fobj.write(b'x' * 4096)
                fobj.truncate()
            s = os.stat(name)
            os_helper.unlink(name)
            return (s.st_blocks * 512 < s.st_size)
        else:
            return False


class PaxReadTest(LongnameTest, ReadTest, unittest.TestCase):

    subdir = "pax"
    longnametype = tarfile.XHDTYPE

    def test_pax_global_headers(self):
        tar = tarfile.open(tarname, encoding="iso8859-1")
        try:
            tarinfo = tar.getmember("pax/regtype1")
            self.assertEqual(tarinfo.uname, "foo")
            self.assertEqual(tarinfo.gname, "bar")
            self.assertEqual(tarinfo.pax_headers.get("VENDOR.umlauts"),
                             "\xc4\xd6\xdc\xe4\xf6\xfc\xdf")

            tarinfo = tar.getmember("pax/regtype2")
            self.assertEqual(tarinfo.uname, "")
            self.assertEqual(tarinfo.gname, "bar")
            self.assertEqual(tarinfo.pax_headers.get("VENDOR.umlauts"),
                             "\xc4\xd6\xdc\xe4\xf6\xfc\xdf")

            tarinfo = tar.getmember("pax/regtype3")
            self.assertEqual(tarinfo.uname, "tarfile")
            self.assertEqual(tarinfo.gname, "tarfile")
            self.assertEqual(tarinfo.pax_headers.get("VENDOR.umlauts"),
                             "\xc4\xd6\xdc\xe4\xf6\xfc\xdf")
        finally:
            tar.close()

    def test_pax_number_fields(self):
        # All following number fields are read from the pax header.
        tar = tarfile.open(tarname, encoding="iso8859-1")
        try:
            tarinfo = tar.getmember("pax/regtype4")
            self.assertEqual(tarinfo.size, 7011)
            self.assertEqual(tarinfo.uid, 123)
            self.assertEqual(tarinfo.gid, 123)
            self.assertEqual(tarinfo.mtime, 1041808783.0)
            self.assertEqual(type(tarinfo.mtime), float)
            self.assertEqual(float(tarinfo.pax_headers["atime"]), 1041808783.0)
            self.assertEqual(float(tarinfo.pax_headers["ctime"]), 1041808783.0)
        finally:
            tar.close()


class WriteTestBase(TarTest):
    # Put all write tests in here that are supposed to be tested
    # in all possible mode combinations.

    def test_fileobj_no_close(self):
        fobj = io.BytesIO()
        with tarfile.open(fileobj=fobj, mode=self.mode) as tar:
            tar.addfile(tarfile.TarInfo("foo"))
        self.assertFalse(fobj.closed, "external fileobjs must never closed")
        # Issue #20238: Incomplete gzip output with mode="w:gz"
        data = fobj.getvalue()
        del tar
        support.gc_collect()
        self.assertFalse(fobj.closed)
        self.assertEqual(data, fobj.getvalue())

    def test_eof_marker(self):
        # Make sure an end of archive marker is written (two zero blocks).
        # tarfile insists on aligning archives to a 20 * 512 byte recordsize.
        # So, we create an archive that has exactly 10240 bytes without the
        # marker, and has 20480 bytes once the marker is written.
        with tarfile.open(tmpname, self.mode) as tar:
            t = tarfile.TarInfo("foo")
            t.size = tarfile.RECORDSIZE - tarfile.BLOCKSIZE
            tar.addfile(t, io.BytesIO(b"a" * t.size))

        with self.open(tmpname, "rb") as fobj:
            self.assertEqual(len(fobj.read()), tarfile.RECORDSIZE * 2)


class WriteTest(WriteTestBase, unittest.TestCase):

    prefix = "w:"

    def test_100_char_name(self):
        # The name field in a tar header stores strings of at most 100 chars.
        # If a string is shorter than 100 chars it has to be padded with '\0',
        # which implies that a string of exactly 100 chars is stored without
        # a trailing '\0'.
        name = "0123456789" * 10
        tar = tarfile.open(tmpname, self.mode)
        try:
            t = tarfile.TarInfo(name)
            tar.addfile(t)
        finally:
            tar.close()

        tar = tarfile.open(tmpname)
        try:
            self.assertEqual(tar.getnames()[0], name,
                    "failed to store 100 char filename")
        finally:
            tar.close()

    def test_tar_size(self):
        # Test for bug #1013882.
        tar = tarfile.open(tmpname, self.mode)
        try:
            path = os.path.join(TEMPDIR, "file")
            with open(path, "wb") as fobj:
                fobj.write(b"aaa")
            tar.add(path)
        finally:
            tar.close()
        self.assertGreater(os.path.getsize(tmpname), 0,
                "tarfile is empty")

    # The test_*_size tests test for bug #1167128.
    def test_file_size(self):
        tar = tarfile.open(tmpname, self.mode)
        try:
            path = os.path.join(TEMPDIR, "file")
            with open(path, "wb"):
                pass
            tarinfo = tar.gettarinfo(path)
            self.assertEqual(tarinfo.size, 0)

            with open(path, "wb") as fobj:
                fobj.write(b"aaa")
            tarinfo = tar.gettarinfo(path)
            self.assertEqual(tarinfo.size, 3)
        finally:
            tar.close()

    def test_directory_size(self):
        path = os.path.join(TEMPDIR, "directory")
        os.mkdir(path)
        try:
            tar = tarfile.open(tmpname, self.mode)
            try:
                tarinfo = tar.gettarinfo(path)
                self.assertEqual(tarinfo.size, 0)
            finally:
                tar.close()
        finally:
            os_helper.rmdir(path)

    # mock the following:
    #  os.listdir: so we know that files are in the wrong order
    def test_ordered_recursion(self):
        path = os.path.join(TEMPDIR, "directory")
        os.mkdir(path)
        open(os.path.join(path, "1"), "a").close()
        open(os.path.join(path, "2"), "a").close()
        try:
            tar = tarfile.open(tmpname, self.mode)
            try:
                with unittest.mock.patch('os.listdir') as mock_listdir:
                    mock_listdir.return_value = ["2", "1"]
                    tar.add(path)
                paths = []
                for m in tar.getmembers():
                    paths.append(os.path.split(m.name)[-1])
                self.assertEqual(paths, ["directory", "1", "2"]);
            finally:
                tar.close()
        finally:
            os_helper.unlink(os.path.join(path, "1"))
            os_helper.unlink(os.path.join(path, "2"))
            os_helper.rmdir(path)

    def test_gettarinfo_pathlike_name(self):
        with tarfile.open(tmpname, self.mode) as tar:
            path = pathlib.Path(TEMPDIR) / "file"
            with open(path, "wb") as fobj:
                fobj.write(b"aaa")
            tarinfo = tar.gettarinfo(path)
            tarinfo2 = tar.gettarinfo(os.fspath(path))
            self.assertIsInstance(tarinfo.name, str)
            self.assertEqual(tarinfo.name, tarinfo2.name)
            self.assertEqual(tarinfo.size, 3)

    @unittest.skipUnless(hasattr(os, "link"),
                         "Missing hardlink implementation")
    def test_link_size(self):
        link = os.path.join(TEMPDIR, "link")
        target = os.path.join(TEMPDIR, "link_target")
        with open(target, "wb") as fobj:
            fobj.write(b"aaa")
        try:
            os.link(target, link)
        except PermissionError as e:
            self.skipTest('os.link(): %s' % e)
        try:
            tar = tarfile.open(tmpname, self.mode)
            try:
                # Record the link target in the inodes list.
                tar.gettarinfo(target)
                tarinfo = tar.gettarinfo(link)
                self.assertEqual(tarinfo.size, 0)
            finally:
                tar.close()
        finally:
            os_helper.unlink(target)
            os_helper.unlink(link)

    @os_helper.skip_unless_symlink
    def test_symlink_size(self):
        path = os.path.join(TEMPDIR, "symlink")
        os.symlink("link_target", path)
        try:
            tar = tarfile.open(tmpname, self.mode)
            try:
                tarinfo = tar.gettarinfo(path)
                self.assertEqual(tarinfo.size, 0)
            finally:
                tar.close()
        finally:
            os_helper.unlink(path)

    def test_add_self(self):
        # Test for #1257255.
        dstname = os.path.abspath(tmpname)
        tar = tarfile.open(tmpname, self.mode)
        try:
            self.assertEqual(tar.name, dstname,
                    "archive name must be absolute")
            tar.add(dstname)
            self.assertEqual(tar.getnames(), [],
                    "added the archive to itself")

            with os_helper.change_cwd(TEMPDIR):
                tar.add(dstname)
            self.assertEqual(tar.getnames(), [],
                    "added the archive to itself")
        finally:
            tar.close()

    def test_filter(self):
        tempdir = os.path.join(TEMPDIR, "filter")
        os.mkdir(tempdir)
        try:
            for name in ("foo", "bar", "baz"):
                name = os.path.join(tempdir, name)
                os_helper.create_empty_file(name)

            def filter(tarinfo):
                if os.path.basename(tarinfo.name) == "bar":
                    return
                tarinfo.uid = 123
                tarinfo.uname = "foo"
                return tarinfo

            tar = tarfile.open(tmpname, self.mode, encoding="iso8859-1")
            try:
                tar.add(tempdir, arcname="empty_dir", filter=filter)
            finally:
                tar.close()

            # Verify that filter is a keyword-only argument
            with self.assertRaises(TypeError):
                tar.add(tempdir, "empty_dir", True, None, filter)

            tar = tarfile.open(tmpname, "r")
            try:
                for tarinfo in tar:
                    self.assertEqual(tarinfo.uid, 123)
                    self.assertEqual(tarinfo.uname, "foo")
                self.assertEqual(len(tar.getmembers()), 3)
            finally:
                tar.close()
        finally:
            os_helper.rmtree(tempdir)

    # Guarantee that stored pathnames are not modified. Don't
    # remove ./ or ../ or double slashes. Still make absolute
    # pathnames relative.
    # For details see bug #6054.
    def _test_pathname(self, path, cmp_path=None, dir=False):
        # Create a tarfile with an empty member named path
        # and compare the stored name with the original.
        foo = os.path.join(TEMPDIR, "foo")
        if not dir:
            os_helper.create_empty_file(foo)
        else:
            os.mkdir(foo)

        tar = tarfile.open(tmpname, self.mode)
        try:
            tar.add(foo, arcname=path)
        finally:
            tar.close()

        tar = tarfile.open(tmpname, "r")
        try:
            t = tar.next()
        finally:
            tar.close()

        if not dir:
            os_helper.unlink(foo)
        else:
            os_helper.rmdir(foo)

        self.assertEqual(t.name, cmp_path or path.replace(os.sep, "/"))


    @os_helper.skip_unless_symlink
    def test_extractall_symlinks(self):
        # Test if extractall works properly when tarfile contains symlinks
        tempdir = os.path.join(TEMPDIR, "testsymlinks")
        temparchive = os.path.join(TEMPDIR, "testsymlinks.tar")
        os.mkdir(tempdir)
        try:
            source_file = os.path.join(tempdir,'source')
            target_file = os.path.join(tempdir,'symlink')
            with open(source_file,'w') as f:
                f.write('something\n')
            os.symlink(source_file, target_file)
            with tarfile.open(temparchive, 'w') as tar:
                tar.add(source_file, arcname="source")
                tar.add(target_file, arcname="symlink")
            # Let's extract it to the location which contains the symlink
            with tarfile.open(temparchive, errorlevel=2) as tar:
                # this should not raise OSError: [Errno 17] File exists
                try:
                    tar.extractall(path=tempdir)
                except OSError:
                    self.fail("extractall failed with symlinked files")
        finally:
            os_helper.unlink(temparchive)
            os_helper.rmtree(tempdir)

    def test_pathnames(self):
        self._test_pathname("foo")
        self._test_pathname(os.path.join("foo", ".", "bar"))
        self._test_pathname(os.path.join("foo", "..", "bar"))
        self._test_pathname(os.path.join(".", "foo"))
        self._test_pathname(os.path.join(".", "foo", "."))
        self._test_pathname(os.path.join(".", "foo", ".", "bar"))
        self._test_pathname(os.path.join(".", "foo", "..", "bar"))
        self._test_pathname(os.path.join(".", "foo", "..", "bar"))
        self._test_pathname(os.path.join("..", "foo"))
        self._test_pathname(os.path.join("..", "foo", ".."))
        self._test_pathname(os.path.join("..", "foo", ".", "bar"))
        self._test_pathname(os.path.join("..", "foo", "..", "bar"))

        self._test_pathname("foo" + os.sep + os.sep + "bar")
        self._test_pathname("foo" + os.sep + os.sep, "foo", dir=True)

    def test_abs_pathnames(self):
        if sys.platform == "win32":
            self._test_pathname("C:\\foo", "foo")
        else:
            self._test_pathname("/foo", "foo")
            self._test_pathname("///foo", "foo")

    def test_cwd(self):
        # Test adding the current working directory.
        with os_helper.change_cwd(TEMPDIR):
            tar = tarfile.open(tmpname, self.mode)
            try:
                tar.add(".")
            finally:
                tar.close()

            tar = tarfile.open(tmpname, "r")
            try:
                for t in tar:
                    if t.name != ".":
                        self.assertTrue(t.name.startswith("./"), t.name)
            finally:
                tar.close()

    def test_open_nonwritable_fileobj(self):
        for exctype in OSError, EOFError, RuntimeError:
            class BadFile(io.BytesIO):
                first = True
                def write(self, data):
                    if self.first:
                        self.first = False
                        raise exctype

            f = BadFile()
            with self.assertRaises(exctype):
                tar = tarfile.open(tmpname, self.mode, fileobj=f,
                                   format=tarfile.PAX_FORMAT,
                                   pax_headers={'non': 'empty'})
            self.assertFalse(f.closed)


class GzipWriteTest(GzipTest, WriteTest):
    pass


class Bz2WriteTest(Bz2Test, WriteTest):
    pass


class LzmaWriteTest(LzmaTest, WriteTest):
    pass


class StreamWriteTest(WriteTestBase, unittest.TestCase):

    prefix = "w|"
    decompressor = None

    def test_stream_padding(self):
        # Test for bug #1543303.
        tar = tarfile.open(tmpname, self.mode)
        tar.close()
        if self.decompressor:
            dec = self.decompressor()
            with open(tmpname, "rb") as fobj:
                data = fobj.read()
            data = dec.decompress(data)
            self.assertFalse(dec.unused_data, "found trailing data")
        else:
            with self.open(tmpname) as fobj:
                data = fobj.read()
        self.assertEqual(data.count(b"\0"), tarfile.RECORDSIZE,
                        "incorrect zero padding")

    @unittest.skipUnless(sys.platform != "win32" and hasattr(os, "umask"),
                         "Missing umask implementation")
    def test_file_mode(self):
        # Test for issue #8464: Create files with correct
        # permissions.
        if os.path.exists(tmpname):
            os_helper.unlink(tmpname)

        original_umask = os.umask(0o022)
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.close()
            mode = os.stat(tmpname).st_mode & 0o777
            self.assertEqual(mode, 0o644, "wrong file permissions")
        finally:
            os.umask(original_umask)


class GzipStreamWriteTest(GzipTest, StreamWriteTest):
    def test_source_directory_not_leaked(self):
        """
        Ensure the source directory is not included in the tar header
        per bpo-41316.
        """
        tarfile.open(tmpname, self.mode).close()
        payload = pathlib.Path(tmpname).read_text(encoding='latin-1')
        assert os.path.dirname(tmpname) not in payload


class Bz2StreamWriteTest(Bz2Test, StreamWriteTest):
    decompressor = bz2.BZ2Decompressor if bz2 else None

class LzmaStreamWriteTest(LzmaTest, StreamWriteTest):
    decompressor = lzma.LZMADecompressor if lzma else None


class GNUWriteTest(unittest.TestCase):
    # This testcase checks for correct creation of GNU Longname
    # and Longlink extended headers (cp. bug #812325).

    def _length(self, s):
        blocks = len(s) // 512 + 1
        return blocks * 512

    def _calc_size(self, name, link=None):
        # Initial tar header
        count = 512

        if len(name) > tarfile.LENGTH_NAME:
            # GNU longname extended header + longname
            count += 512
            count += self._length(name)
        if link is not None and len(link) > tarfile.LENGTH_LINK:
            # GNU longlink extended header + longlink
            count += 512
            count += self._length(link)
        return count

    def _test(self, name, link=None):
        tarinfo = tarfile.TarInfo(name)
        if link:
            tarinfo.linkname = link
            tarinfo.type = tarfile.LNKTYPE

        tar = tarfile.open(tmpname, "w")
        try:
            tar.format = tarfile.GNU_FORMAT
            tar.addfile(tarinfo)

            v1 = self._calc_size(name, link)
            v2 = tar.offset
            self.assertEqual(v1, v2, "GNU longname/longlink creation failed")
        finally:
            tar.close()

        tar = tarfile.open(tmpname)
        try:
            member = tar.next()
            self.assertIsNotNone(member,
                    "unable to read longname member")
            self.assertEqual(tarinfo.name, member.name,
                    "unable to read longname member")
            self.assertEqual(tarinfo.linkname, member.linkname,
                    "unable to read longname member")
        finally:
            tar.close()

    def test_longname_1023(self):
        self._test(("longnam/" * 127) + "longnam")

    def test_longname_1024(self):
        self._test(("longnam/" * 127) + "longname")

    def test_longname_1025(self):
        self._test(("longnam/" * 127) + "longname_")

    def test_longlink_1023(self):
        self._test("name", ("longlnk/" * 127) + "longlnk")

    def test_longlink_1024(self):
        self._test("name", ("longlnk/" * 127) + "longlink")

    def test_longlink_1025(self):
        self._test("name", ("longlnk/" * 127) + "longlink_")

    def test_longnamelink_1023(self):
        self._test(("longnam/" * 127) + "longnam",
                   ("longlnk/" * 127) + "longlnk")

    def test_longnamelink_1024(self):
        self._test(("longnam/" * 127) + "longname",
                   ("longlnk/" * 127) + "longlink")

    def test_longnamelink_1025(self):
        self._test(("longnam/" * 127) + "longname_",
                   ("longlnk/" * 127) + "longlink_")


class DeviceHeaderTest(WriteTestBase, unittest.TestCase):

    prefix = "w:"

    def test_headers_written_only_for_device_files(self):
        # Regression test for bpo-18819.
        tempdir = os.path.join(TEMPDIR, "device_header_test")
        os.mkdir(tempdir)
        try:
            tar = tarfile.open(tmpname, self.mode)
            try:
                input_blk = tarfile.TarInfo(name="my_block_device")
                input_reg = tarfile.TarInfo(name="my_regular_file")
                input_blk.type = tarfile.BLKTYPE
                input_reg.type = tarfile.REGTYPE
                tar.addfile(input_blk)
                tar.addfile(input_reg)
            finally:
                tar.close()

            # devmajor and devminor should be *interpreted* as 0 in both...
            tar = tarfile.open(tmpname, "r")
            try:
                output_blk = tar.getmember("my_block_device")
                output_reg = tar.getmember("my_regular_file")
            finally:
                tar.close()
            self.assertEqual(output_blk.devmajor, 0)
            self.assertEqual(output_blk.devminor, 0)
            self.assertEqual(output_reg.devmajor, 0)
            self.assertEqual(output_reg.devminor, 0)

            # ...but the fields should not actually be set on regular files:
            with open(tmpname, "rb") as infile:
                buf = infile.read()
            buf_blk = buf[output_blk.offset:output_blk.offset_data]
            buf_reg = buf[output_reg.offset:output_reg.offset_data]
            # See `struct posixheader` in GNU docs for byte offsets:
            # <https://www.gnu.org/software/tar/manual/html_node/Standard.html>
            device_headers = slice(329, 329 + 16)
            self.assertEqual(buf_blk[device_headers], b"0000000\0" * 2)
            self.assertEqual(buf_reg[device_headers], b"\0" * 16)
        finally:
            os_helper.rmtree(tempdir)


class CreateTest(WriteTestBase, unittest.TestCase):

    prefix = "x:"

    file_path = os.path.join(TEMPDIR, "spameggs42")

    def setUp(self):
        os_helper.unlink(tmpname)

    @classmethod
    def setUpClass(cls):
        with open(cls.file_path, "wb") as fobj:
            fobj.write(b"aaa")

    @classmethod
    def tearDownClass(cls):
        os_helper.unlink(cls.file_path)

    def test_create(self):
        with tarfile.open(tmpname, self.mode) as tobj:
            tobj.add(self.file_path)

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

    def test_create_existing(self):
        with tarfile.open(tmpname, self.mode) as tobj:
            tobj.add(self.file_path)

        with self.assertRaises(FileExistsError):
            tobj = tarfile.open(tmpname, self.mode)

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

    def test_create_taropen(self):
        with self.taropen(tmpname, "x") as tobj:
            tobj.add(self.file_path)

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

    def test_create_existing_taropen(self):
        with self.taropen(tmpname, "x") as tobj:
            tobj.add(self.file_path)

        with self.assertRaises(FileExistsError):
            with self.taropen(tmpname, "x"):
                pass

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn("spameggs42", names[0])

    def test_create_pathlike_name(self):
        with tarfile.open(pathlib.Path(tmpname), self.mode) as tobj:
            self.assertIsInstance(tobj.name, str)
            self.assertEqual(tobj.name, os.path.abspath(tmpname))
            tobj.add(pathlib.Path(self.file_path))
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

    def test_create_taropen_pathlike_name(self):
        with self.taropen(pathlib.Path(tmpname), "x") as tobj:
            self.assertIsInstance(tobj.name, str)
            self.assertEqual(tobj.name, os.path.abspath(tmpname))
            tobj.add(pathlib.Path(self.file_path))
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])

        with self.taropen(tmpname) as tobj:
            names = tobj.getnames()
        self.assertEqual(len(names), 1)
        self.assertIn('spameggs42', names[0])


class GzipCreateTest(GzipTest, CreateTest):
    pass


class Bz2CreateTest(Bz2Test, CreateTest):
    pass


class LzmaCreateTest(LzmaTest, CreateTest):
    pass


class CreateWithXModeTest(CreateTest):

    prefix = "x"

    test_create_taropen = None
    test_create_existing_taropen = None


@unittest.skipUnless(hasattr(os, "link"), "Missing hardlink implementation")
class HardlinkTest(unittest.TestCase):
    # Test the creation of LNKTYPE (hardlink) members in an archive.

    def setUp(self):
        self.foo = os.path.join(TEMPDIR, "foo")
        self.bar = os.path.join(TEMPDIR, "bar")

        with open(self.foo, "wb") as fobj:
            fobj.write(b"foo")

        try:
            os.link(self.foo, self.bar)
        except PermissionError as e:
            self.skipTest('os.link(): %s' % e)

        self.tar = tarfile.open(tmpname, "w")
        self.tar.add(self.foo)

    def tearDown(self):
        self.tar.close()
        os_helper.unlink(self.foo)
        os_helper.unlink(self.bar)

    def test_add_twice(self):
        # The same name will be added as a REGTYPE every
        # time regardless of st_nlink.
        tarinfo = self.tar.gettarinfo(self.foo)
        self.assertEqual(tarinfo.type, tarfile.REGTYPE,
                "add file as regular failed")

    def test_add_hardlink(self):
        tarinfo = self.tar.gettarinfo(self.bar)
        self.assertEqual(tarinfo.type, tarfile.LNKTYPE,
                "add file as hardlink failed")

    def test_dereference_hardlink(self):
        self.tar.dereference = True
        tarinfo = self.tar.gettarinfo(self.bar)
        self.assertEqual(tarinfo.type, tarfile.REGTYPE,
                "dereferencing hardlink failed")


class PaxWriteTest(GNUWriteTest):

    def _test(self, name, link=None):
        # See GNUWriteTest.
        tarinfo = tarfile.TarInfo(name)
        if link:
            tarinfo.linkname = link
            tarinfo.type = tarfile.LNKTYPE

        tar = tarfile.open(tmpname, "w", format=tarfile.PAX_FORMAT)
        try:
            tar.addfile(tarinfo)
        finally:
            tar.close()

        tar = tarfile.open(tmpname)
        try:
            if link:
                l = tar.getmembers()[0].linkname
                self.assertEqual(link, l, "PAX longlink creation failed")
            else:
                n = tar.getmembers()[0].name
                self.assertEqual(name, n, "PAX longname creation failed")
        finally:
            tar.close()

    def test_pax_global_header(self):
        pax_headers = {
                "foo": "bar",
                "uid": "0",
                "mtime": "1.23",
                "test": "\xe4\xf6\xfc",
                "\xe4\xf6\xfc": "test"}

        tar = tarfile.open(tmpname, "w", format=tarfile.PAX_FORMAT,
                pax_headers=pax_headers)
        try:
            tar.addfile(tarfile.TarInfo("test"))
        finally:
            tar.close()

        # Test if the global header was written correctly.
        tar = tarfile.open(tmpname, encoding="iso8859-1")
        try:
            self.assertEqual(tar.pax_headers, pax_headers)
            self.assertEqual(tar.getmembers()[0].pax_headers, pax_headers)
            # Test if all the fields are strings.
            for key, val in tar.pax_headers.items():
                self.assertIsNot(type(key), bytes)
                self.assertIsNot(type(val), bytes)
                if key in tarfile.PAX_NUMBER_FIELDS:
                    try:
                        tarfile.PAX_NUMBER_FIELDS[key](val)
                    except (TypeError, ValueError):
                        self.fail("unable to convert pax header field")
        finally:
            tar.close()

    def test_pax_extended_header(self):
        # The fields from the pax header have priority over the
        # TarInfo.
        pax_headers = {"path": "foo", "uid": "123"}

        tar = tarfile.open(tmpname, "w", format=tarfile.PAX_FORMAT,
                           encoding="iso8859-1")
        try:
            t = tarfile.TarInfo()
            t.name = "\xe4\xf6\xfc" # non-ASCII
            t.uid = 8**8 # too large
            t.pax_headers = pax_headers
            tar.addfile(t)
        finally:
            tar.close()

        tar = tarfile.open(tmpname, encoding="iso8859-1")
        try:
            t = tar.getmembers()[0]
            self.assertEqual(t.pax_headers, pax_headers)
            self.assertEqual(t.name, "foo")
            self.assertEqual(t.uid, 123)
        finally:
            tar.close()


class UnicodeTest:

    def test_iso8859_1_filename(self):
        self._test_unicode_filename("iso8859-1")

    def test_utf7_filename(self):
        self._test_unicode_filename("utf7")

    def test_utf8_filename(self):
        self._test_unicode_filename("utf-8")

    def _test_unicode_filename(self, encoding):
        tar = tarfile.open(tmpname, "w", format=self.format,
                           encoding=encoding, errors="strict")
        try:
            name = "\xe4\xf6\xfc"
            tar.addfile(tarfile.TarInfo(name))
        finally:
            tar.close()

        tar = tarfile.open(tmpname, encoding=encoding)
        try:
            self.assertEqual(tar.getmembers()[0].name, name)
        finally:
            tar.close()

    def test_unicode_filename_error(self):
        tar = tarfile.open(tmpname, "w", format=self.format,
                           encoding="ascii", errors="strict")
        try:
            tarinfo = tarfile.TarInfo()

            tarinfo.name = "\xe4\xf6\xfc"
            self.assertRaises(UnicodeError, tar.addfile, tarinfo)

            tarinfo.name = "foo"
            tarinfo.uname = "\xe4\xf6\xfc"
            self.assertRaises(UnicodeError, tar.addfile, tarinfo)
        finally:
            tar.close()

    def test_unicode_argument(self):
        tar = tarfile.open(tarname, "r",
                           encoding="iso8859-1", errors="strict")
        try:
            for t in tar:
                self.assertIs(type(t.name), str)
                self.assertIs(type(t.linkname), str)
                self.assertIs(type(t.uname), str)
                self.assertIs(type(t.gname), str)
        finally:
            tar.close()

    def test_uname_unicode(self):
        t = tarfile.TarInfo("foo")
        t.uname = "\xe4\xf6\xfc"
        t.gname = "\xe4\xf6\xfc"

        tar = tarfile.open(tmpname, mode="w", format=self.format,
                           encoding="iso8859-1")
        try:
            tar.addfile(t)
        finally:
            tar.close()

        tar = tarfile.open(tmpname, encoding="iso8859-1")
        try:
            t = tar.getmember("foo")
            self.assertEqual(t.uname, "\xe4\xf6\xfc")
            self.assertEqual(t.gname, "\xe4\xf6\xfc")

            if self.format != tarfile.PAX_FORMAT:
                tar.close()
                tar = tarfile.open(tmpname, encoding="ascii")
                t = tar.getmember("foo")
                self.assertEqual(t.uname, "\udce4\udcf6\udcfc")
                self.assertEqual(t.gname, "\udce4\udcf6\udcfc")
        finally:
            tar.close()


class UstarUnicodeTest(UnicodeTest, unittest.TestCase):

    format = tarfile.USTAR_FORMAT

    # Test whether the utf-8 encoded version of a filename exceeds the 100
    # bytes name field limit (every occurrence of '\xff' will be expanded to 2
    # bytes).
    def test_unicode_name1(self):
        self._test_ustar_name("0123456789" * 10)
        self._test_ustar_name("0123456789" * 10 + "0", ValueError)
        self._test_ustar_name("0123456789" * 9 + "01234567\xff")
        self._test_ustar_name("0123456789" * 9 + "012345678\xff", ValueError)

    def test_unicode_name2(self):
        self._test_ustar_name("0123456789" * 9 + "012345\xff\xff")
        self._test_ustar_name("0123456789" * 9 + "0123456\xff\xff", ValueError)

    # Test whether the utf-8 encoded version of a filename exceeds the 155
    # bytes prefix + '/' + 100 bytes name limit.
    def test_unicode_longname1(self):
        self._test_ustar_name("0123456789" * 15 + "01234/" + "0123456789" * 10)
        self._test_ustar_name("0123456789" * 15 + "0123/4" + "0123456789" * 10, ValueError)
        self._test_ustar_name("0123456789" * 15 + "012\xff/" + "0123456789" * 10)
        self._test_ustar_name("0123456789" * 15 + "0123\xff/" + "0123456789" * 10, ValueError)

    def test_unicode_longname2(self):
        self._test_ustar_name("0123456789" * 15 + "01\xff/2" + "0123456789" * 10, ValueError)
        self._test_ustar_name("0123456789" * 15 + "01\xff\xff/" + "0123456789" * 10, ValueError)

    def test_unicode_longname3(self):
        self._test_ustar_name("0123456789" * 15 + "01\xff\xff/2" + "0123456789" * 10, ValueError)
        self._test_ustar_name("0123456789" * 15 + "01234/" + "0123456789" * 9 + "01234567\xff")
        self._test_ustar_name("0123456789" * 15 + "01234/" + "0123456789" * 9 + "012345678\xff", ValueError)

    def test_unicode_longname4(self):
        self._test_ustar_name("0123456789" * 15 + "01234/" + "0123456789" * 9 + "012345\xff\xff")
        self._test_ustar_name("0123456789" * 15 + "01234/" + "0123456789" * 9 + "0123456\xff\xff", ValueError)

    def _test_ustar_name(self, name, exc=None):
        with tarfile.open(tmpname, "w", format=self.format, encoding="utf-8") as tar:
            t = tarfile.TarInfo(name)
            if exc is None:
                tar.addfile(t)
            else:
                self.assertRaises(exc, tar.addfile, t)

        if exc is None:
            with tarfile.open(tmpname, "r", encoding="utf-8") as tar:
                for t in tar:
                    self.assertEqual(name, t.name)
                    break

    # Test the same as above for the 100 bytes link field.
    def test_unicode_link1(self):
        self._test_ustar_link("0123456789" * 10)
        self._test_ustar_link("0123456789" * 10 + "0", ValueError)
        self._test_ustar_link("0123456789" * 9 + "01234567\xff")
        self._test_ustar_link("0123456789" * 9 + "012345678\xff", ValueError)

    def test_unicode_link2(self):
        self._test_ustar_link("0123456789" * 9 + "012345\xff\xff")
        self._test_ustar_link("0123456789" * 9 + "0123456\xff\xff", ValueError)

    def _test_ustar_link(self, name, exc=None):
        with tarfile.open(tmpname, "w", format=self.format, encoding="utf-8") as tar:
            t = tarfile.TarInfo("foo")
            t.linkname = name
            if exc is None:
                tar.addfile(t)
            else:
                self.assertRaises(exc, tar.addfile, t)

        if exc is None:
            with tarfile.open(tmpname, "r", encoding="utf-8") as tar:
                for t in tar:
                    self.assertEqual(name, t.linkname)
                    break


class GNUUnicodeTest(UnicodeTest, unittest.TestCase):

    format = tarfile.GNU_FORMAT

    def test_bad_pax_header(self):
        # Test for issue #8633. GNU tar <= 1.23 creates raw binary fields
        # without a hdrcharset=BINARY header.
        for encoding, name in (
                ("utf-8", "pax/bad-pax-\udce4\udcf6\udcfc"),
                ("iso8859-1", "pax/bad-pax-\xe4\xf6\xfc"),):
            with tarfile.open(tarname, encoding=encoding,
                              errors="surrogateescape") as tar:
                try:
                    t = tar.getmember(name)
                except KeyError:
                    self.fail("unable to read bad GNU tar pax header")


class PAXUnicodeTest(UnicodeTest, unittest.TestCase):

    format = tarfile.PAX_FORMAT

    # PAX_FORMAT ignores encoding in write mode.
    test_unicode_filename_error = None

    def test_binary_header(self):
        # Test a POSIX.1-2008 compatible header with a hdrcharset=BINARY field.
        for encoding, name in (
                ("utf-8", "pax/hdrcharset-\udce4\udcf6\udcfc"),
                ("iso8859-1", "pax/hdrcharset-\xe4\xf6\xfc"),):
            with tarfile.open(tarname, encoding=encoding,
                              errors="surrogateescape") as tar:
                try:
                    t = tar.getmember(name)
                except KeyError:
                    self.fail("unable to read POSIX.1-2008 binary header")


class AppendTestBase:
    # Test append mode (cp. patch #1652681).

    def setUp(self):
        self.tarname = tmpname
        if os.path.exists(self.tarname):
            os_helper.unlink(self.tarname)

    def _create_testtar(self, mode="w:"):
        with tarfile.open(tarname, encoding="iso8859-1") as src:
            t = src.getmember("ustar/regtype")
            t.name = "foo"
            with src.extractfile(t) as f:
                with tarfile.open(self.tarname, mode) as tar:
                    tar.addfile(t, f)

    def test_append_compressed(self):
        self._create_testtar("w:" + self.suffix)
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

class AppendTest(AppendTestBase, unittest.TestCase):
    test_append_compressed = None

    def _add_testfile(self, fileobj=None):
        with tarfile.open(self.tarname, "a", fileobj=fileobj) as tar:
            tar.addfile(tarfile.TarInfo("bar"))

    def _test(self, names=["bar"], fileobj=None):
        with tarfile.open(self.tarname, fileobj=fileobj) as tar:
            self.assertEqual(tar.getnames(), names)

    def test_non_existing(self):
        self._add_testfile()
        self._test()

    def test_empty(self):
        tarfile.open(self.tarname, "w:").close()
        self._add_testfile()
        self._test()

    def test_empty_fileobj(self):
        fobj = io.BytesIO(b"\0" * 1024)
        self._add_testfile(fobj)
        fobj.seek(0)
        self._test(fileobj=fobj)

    def test_fileobj(self):
        self._create_testtar()
        with open(self.tarname, "rb") as fobj:
            data = fobj.read()
        fobj = io.BytesIO(data)
        self._add_testfile(fobj)
        fobj.seek(0)
        self._test(names=["foo", "bar"], fileobj=fobj)

    def test_existing(self):
        self._create_testtar()
        self._add_testfile()
        self._test(names=["foo", "bar"])

    # Append mode is supposed to fail if the tarfile to append to
    # does not end with a zero block.
    def _test_error(self, data):
        with open(self.tarname, "wb") as fobj:
            fobj.write(data)
        self.assertRaises(tarfile.ReadError, self._add_testfile)

    def test_null(self):
        self._test_error(b"")

    def test_incomplete(self):
        self._test_error(b"\0" * 13)

    def test_premature_eof(self):
        data = tarfile.TarInfo("foo").tobuf()
        self._test_error(data)

    def test_trailing_garbage(self):
        data = tarfile.TarInfo("foo").tobuf()
        self._test_error(data + b"\0" * 13)

    def test_invalid(self):
        self._test_error(b"a" * 512)

class GzipAppendTest(GzipTest, AppendTestBase, unittest.TestCase):
    pass

class Bz2AppendTest(Bz2Test, AppendTestBase, unittest.TestCase):
    pass

class LzmaAppendTest(LzmaTest, AppendTestBase, unittest.TestCase):
    pass


class LimitsTest(unittest.TestCase):

    def test_ustar_limits(self):
        # 100 char name
        tarinfo = tarfile.TarInfo("0123456789" * 10)
        tarinfo.tobuf(tarfile.USTAR_FORMAT)

        # 101 char name that cannot be stored
        tarinfo = tarfile.TarInfo("0123456789" * 10 + "0")
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.USTAR_FORMAT)

        # 256 char name with a slash at pos 156
        tarinfo = tarfile.TarInfo("123/" * 62 + "longname")
        tarinfo.tobuf(tarfile.USTAR_FORMAT)

        # 256 char name that cannot be stored
        tarinfo = tarfile.TarInfo("1234567/" * 31 + "longname")
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.USTAR_FORMAT)

        # 512 char name
        tarinfo = tarfile.TarInfo("123/" * 126 + "longname")
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.USTAR_FORMAT)

        # 512 char linkname
        tarinfo = tarfile.TarInfo("longlink")
        tarinfo.linkname = "123/" * 126 + "longname"
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.USTAR_FORMAT)

        # uid > 8 digits
        tarinfo = tarfile.TarInfo("name")
        tarinfo.uid = 0o10000000
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.USTAR_FORMAT)

    def test_gnu_limits(self):
        tarinfo = tarfile.TarInfo("123/" * 126 + "longname")
        tarinfo.tobuf(tarfile.GNU_FORMAT)

        tarinfo = tarfile.TarInfo("longlink")
        tarinfo.linkname = "123/" * 126 + "longname"
        tarinfo.tobuf(tarfile.GNU_FORMAT)

        # uid >= 256 ** 7
        tarinfo = tarfile.TarInfo("name")
        tarinfo.uid = 0o4000000000000000000
        self.assertRaises(ValueError, tarinfo.tobuf, tarfile.GNU_FORMAT)

    def test_pax_limits(self):
        tarinfo = tarfile.TarInfo("123/" * 126 + "longname")
        tarinfo.tobuf(tarfile.PAX_FORMAT)

        tarinfo = tarfile.TarInfo("longlink")
        tarinfo.linkname = "123/" * 126 + "longname"
        tarinfo.tobuf(tarfile.PAX_FORMAT)

        tarinfo = tarfile.TarInfo("name")
        tarinfo.uid = 0o4000000000000000000
        tarinfo.tobuf(tarfile.PAX_FORMAT)


class MiscTest(unittest.TestCase):

    def test_char_fields(self):
        self.assertEqual(tarfile.stn("foo", 8, "ascii", "strict"),
                         b"foo\0\0\0\0\0")
        self.assertEqual(tarfile.stn("foobar", 3, "ascii", "strict"),
                         b"foo")
        self.assertEqual(tarfile.nts(b"foo\0\0\0\0\0", "ascii", "strict"),
                         "foo")
        self.assertEqual(tarfile.nts(b"foo\0bar\0", "ascii", "strict"),
                         "foo")

    def test_read_number_fields(self):
        # Issue 13158: Test if GNU tar specific base-256 number fields
        # are decoded correctly.
        self.assertEqual(tarfile.nti(b"0000001\x00"), 1)
        self.assertEqual(tarfile.nti(b"7777777\x00"), 0o7777777)
        self.assertEqual(tarfile.nti(b"\x80\x00\x00\x00\x00\x20\x00\x00"),
                         0o10000000)
        self.assertEqual(tarfile.nti(b"\x80\x00\x00\x00\xff\xff\xff\xff"),
                         0xffffffff)
        self.assertEqual(tarfile.nti(b"\xff\xff\xff\xff\xff\xff\xff\xff"),
                         -1)
        self.assertEqual(tarfile.nti(b"\xff\xff\xff\xff\xff\xff\xff\x9c"),
                         -100)
        self.assertEqual(tarfile.nti(b"\xff\x00\x00\x00\x00\x00\x00\x00"),
                         -0x100000000000000)

        # Issue 24514: Test if empty number fields are converted to zero.
        self.assertEqual(tarfile.nti(b"\0"), 0)
        self.assertEqual(tarfile.nti(b"       \0"), 0)

    def test_write_number_fields(self):
        self.assertEqual(tarfile.itn(1), b"0000001\x00")
        self.assertEqual(tarfile.itn(0o7777777), b"7777777\x00")
        self.assertEqual(tarfile.itn(0o10000000, format=tarfile.GNU_FORMAT),
                         b"\x80\x00\x00\x00\x00\x20\x00\x00")
        self.assertEqual(tarfile.itn(0xffffffff, format=tarfile.GNU_FORMAT),
                         b"\x80\x00\x00\x00\xff\xff\xff\xff")
        self.assertEqual(tarfile.itn(-1, format=tarfile.GNU_FORMAT),
                         b"\xff\xff\xff\xff\xff\xff\xff\xff")
        self.assertEqual(tarfile.itn(-100, format=tarfile.GNU_FORMAT),
                         b"\xff\xff\xff\xff\xff\xff\xff\x9c")
        self.assertEqual(tarfile.itn(-0x100000000000000,
                                     format=tarfile.GNU_FORMAT),
                         b"\xff\x00\x00\x00\x00\x00\x00\x00")

        # Issue 32713: Test if itn() supports float values outside the
        # non-GNU format range
        self.assertEqual(tarfile.itn(-100.0, format=tarfile.GNU_FORMAT),
                         b"\xff\xff\xff\xff\xff\xff\xff\x9c")
        self.assertEqual(tarfile.itn(8 ** 12 + 0.0, format=tarfile.GNU_FORMAT),
                         b"\x80\x00\x00\x10\x00\x00\x00\x00")
        self.assertEqual(tarfile.nti(tarfile.itn(-0.1, format=tarfile.GNU_FORMAT)), 0)

    def test_number_field_limits(self):
        with self.assertRaises(ValueError):
            tarfile.itn(-1, 8, tarfile.USTAR_FORMAT)
        with self.assertRaises(ValueError):
            tarfile.itn(0o10000000, 8, tarfile.USTAR_FORMAT)
        with self.assertRaises(ValueError):
            tarfile.itn(-0x10000000001, 6, tarfile.GNU_FORMAT)
        with self.assertRaises(ValueError):
            tarfile.itn(0x10000000000, 6, tarfile.GNU_FORMAT)

    def test__all__(self):
        not_exported = {
            'version', 'grp', 'pwd', 'symlink_exception', 'NUL', 'BLOCKSIZE',
            'RECORDSIZE', 'GNU_MAGIC', 'POSIX_MAGIC', 'LENGTH_NAME',
            'LENGTH_LINK', 'LENGTH_PREFIX', 'REGTYPE', 'AREGTYPE', 'LNKTYPE',
            'SYMTYPE', 'CHRTYPE', 'BLKTYPE', 'DIRTYPE', 'FIFOTYPE', 'CONTTYPE',
            'GNUTYPE_LONGNAME', 'GNUTYPE_LONGLINK', 'GNUTYPE_SPARSE',
            'XHDTYPE', 'XGLTYPE', 'SOLARIS_XHDTYPE', 'SUPPORTED_TYPES',
            'REGULAR_TYPES', 'GNU_TYPES', 'PAX_FIELDS', 'PAX_NAME_FIELDS',
            'PAX_NUMBER_FIELDS', 'stn', 'nts', 'nti', 'itn', 'calc_chksums',
            'copyfileobj', 'filemode', 'EmptyHeaderError',
            'TruncatedHeaderError', 'EOFHeaderError', 'InvalidHeaderError',
            'SubsequentHeaderError', 'ExFileObject', 'main'}
        support.check__all__(self, tarfile, not_exported=not_exported)

    def test_useful_error_message_when_modules_missing(self):
        fname = os.path.join(os.path.dirname(__file__), 'testtar.tar.xz')
        with self.assertRaises(tarfile.ReadError) as excinfo:
            error = tarfile.CompressionError('lzma module is not available'),
            with unittest.mock.patch.object(tarfile.TarFile, 'xzopen', side_effect=error):
                tarfile.open(fname)

        self.assertIn(
            "\n- method xz: CompressionError('lzma module is not available')\n",
            str(excinfo.exception),
        )


class CommandLineTest(unittest.TestCase):

    def tarfilecmd(self, *args, **kwargs):
        rc, out, err = script_helper.assert_python_ok('-m', 'tarfile', *args,
                                                      **kwargs)
        return out.replace(os.linesep.encode(), b'\n')

    def tarfilecmd_failure(self, *args):
        return script_helper.assert_python_failure('-m', 'tarfile', *args)

    def make_simple_tarfile(self, tar_name):
        files = [support.findfile('tokenize_tests.txt'),
                 support.findfile('tokenize_tests-no-coding-cookie-'
                                  'and-utf8-bom-sig-only.txt')]
        self.addCleanup(os_helper.unlink, tar_name)
        with tarfile.open(tar_name, 'w') as tf:
            for tardata in files:
                tf.add(tardata, arcname=os.path.basename(tardata))

    def test_bad_use(self):
        rc, out, err = self.tarfilecmd_failure()
        self.assertEqual(out, b'')
        self.assertIn(b'usage', err.lower())
        self.assertIn(b'error', err.lower())
        self.assertIn(b'required', err.lower())
        rc, out, err = self.tarfilecmd_failure('-l', '')
        self.assertEqual(out, b'')
        self.assertNotEqual(err.strip(), b'')

    def test_test_command(self):
        for tar_name in testtarnames:
            for opt in '-t', '--test':
                out = self.tarfilecmd(opt, tar_name)
                self.assertEqual(out, b'')

    def test_test_command_verbose(self):
        for tar_name in testtarnames:
            for opt in '-v', '--verbose':
                out = self.tarfilecmd(opt, '-t', tar_name,
                                      PYTHONIOENCODING='utf-8')
                self.assertIn(b'is a tar archive.\n', out)

    def test_test_command_invalid_file(self):
        zipname = support.findfile('zipdir.zip')
        rc, out, err = self.tarfilecmd_failure('-t', zipname)
        self.assertIn(b' is not a tar archive.', err)
        self.assertEqual(out, b'')
        self.assertEqual(rc, 1)

        for tar_name in testtarnames:
            with self.subTest(tar_name=tar_name):
                with open(tar_name, 'rb') as f:
                    data = f.read()
                try:
                    with open(tmpname, 'wb') as f:
                        f.write(data[:511])
                    rc, out, err = self.tarfilecmd_failure('-t', tmpname)
                    self.assertEqual(out, b'')
                    self.assertEqual(rc, 1)
                finally:
                    os_helper.unlink(tmpname)

    def test_list_command(self):
        for tar_name in testtarnames:
            with support.captured_stdout() as t:
                with tarfile.open(tar_name, 'r') as tf:
                    tf.list(verbose=False)
            expected = t.getvalue().encode('ascii', 'backslashreplace')
            for opt in '-l', '--list':
                out = self.tarfilecmd(opt, tar_name,
                                      PYTHONIOENCODING='ascii')
                self.assertEqual(out, expected)

    def test_list_command_verbose(self):
        for tar_name in testtarnames:
            with support.captured_stdout() as t:
                with tarfile.open(tar_name, 'r') as tf:
                    tf.list(verbose=True)
            expected = t.getvalue().encode('ascii', 'backslashreplace')
            for opt in '-v', '--verbose':
                out = self.tarfilecmd(opt, '-l', tar_name,
                                      PYTHONIOENCODING='ascii')
                self.assertEqual(out, expected)

    def test_list_command_invalid_file(self):
        zipname = support.findfile('zipdir.zip')
        rc, out, err = self.tarfilecmd_failure('-l', zipname)
        self.assertIn(b' is not a tar archive.', err)
        self.assertEqual(out, b'')
        self.assertEqual(rc, 1)

    def test_create_command(self):
        files = [support.findfile('tokenize_tests.txt'),
                 support.findfile('tokenize_tests-no-coding-cookie-'
                                  'and-utf8-bom-sig-only.txt')]
        for opt in '-c', '--create':
            try:
                out = self.tarfilecmd(opt, tmpname, *files)
                self.assertEqual(out, b'')
                with tarfile.open(tmpname) as tar:
                    tar.getmembers()
            finally:
                os_helper.unlink(tmpname)

    def test_create_command_verbose(self):
        files = [support.findfile('tokenize_tests.txt'),
                 support.findfile('tokenize_tests-no-coding-cookie-'
                                  'and-utf8-bom-sig-only.txt')]
        for opt in '-v', '--verbose':
            try:
                out = self.tarfilecmd(opt, '-c', tmpname, *files,
                                      PYTHONIOENCODING='utf-8')
                self.assertIn(b' file created.', out)
                with tarfile.open(tmpname) as tar:
                    tar.getmembers()
            finally:
                os_helper.unlink(tmpname)

    def test_create_command_dotless_filename(self):
        files = [support.findfile('tokenize_tests.txt')]
        try:
            out = self.tarfilecmd('-c', dotlessname, *files)
            self.assertEqual(out, b'')
            with tarfile.open(dotlessname) as tar:
                tar.getmembers()
        finally:
            os_helper.unlink(dotlessname)

    def test_create_command_dot_started_filename(self):
        tar_name = os.path.join(TEMPDIR, ".testtar")
        files = [support.findfile('tokenize_tests.txt')]
        try:
            out = self.tarfilecmd('-c', tar_name, *files)
            self.assertEqual(out, b'')
            with tarfile.open(tar_name) as tar:
                tar.getmembers()
        finally:
            os_helper.unlink(tar_name)

    def test_create_command_compressed(self):
        files = [support.findfile('tokenize_tests.txt'),
                 support.findfile('tokenize_tests-no-coding-cookie-'
                                  'and-utf8-bom-sig-only.txt')]
        for filetype in (GzipTest, Bz2Test, LzmaTest):
            if not filetype.open:
                continue
            try:
                tar_name = tmpname + '.' + filetype.suffix
                out = self.tarfilecmd('-c', tar_name, *files)
                with filetype.taropen(tar_name) as tar:
                    tar.getmembers()
            finally:
                os_helper.unlink(tar_name)

    def test_extract_command(self):
        self.make_simple_tarfile(tmpname)
        for opt in '-e', '--extract':
            try:
                with os_helper.temp_cwd(tarextdir):
                    out = self.tarfilecmd(opt, tmpname)
                self.assertEqual(out, b'')
            finally:
                os_helper.rmtree(tarextdir)

    def test_extract_command_verbose(self):
        self.make_simple_tarfile(tmpname)
        for opt in '-v', '--verbose':
            try:
                with os_helper.temp_cwd(tarextdir):
                    out = self.tarfilecmd(opt, '-e', tmpname,
                                          PYTHONIOENCODING='utf-8')
                self.assertIn(b' file is extracted.', out)
            finally:
                os_helper.rmtree(tarextdir)

    def test_extract_command_different_directory(self):
        self.make_simple_tarfile(tmpname)
        try:
            with os_helper.temp_cwd(tarextdir):
                out = self.tarfilecmd('-e', tmpname, 'spamdir')
            self.assertEqual(out, b'')
        finally:
            os_helper.rmtree(tarextdir)

    def test_extract_command_invalid_file(self):
        zipname = support.findfile('zipdir.zip')
        with os_helper.temp_cwd(tarextdir):
            rc, out, err = self.tarfilecmd_failure('-e', zipname)
        self.assertIn(b' is not a tar archive.', err)
        self.assertEqual(out, b'')
        self.assertEqual(rc, 1)


class ContextManagerTest(unittest.TestCase):

    def test_basic(self):
        with tarfile.open(tarname) as tar:
            self.assertFalse(tar.closed, "closed inside runtime context")
        self.assertTrue(tar.closed, "context manager failed")

    def test_closed(self):
        # The __enter__() method is supposed to raise OSError
        # if the TarFile object is already closed.
        tar = tarfile.open(tarname)
        tar.close()
        with self.assertRaises(OSError):
            with tar:
                pass

    def test_exception(self):
        # Test if the OSError exception is passed through properly.
        with self.assertRaises(Exception) as exc:
            with tarfile.open(tarname) as tar:
                raise OSError
        self.assertIsInstance(exc.exception, OSError,
                              "wrong exception raised in context manager")
        self.assertTrue(tar.closed, "context manager failed")

    def test_no_eof(self):
        # __exit__() must not write end-of-archive blocks if an
        # exception was raised.
        try:
            with tarfile.open(tmpname, "w") as tar:
                raise Exception
        except:
            pass
        self.assertEqual(os.path.getsize(tmpname), 0,
                "context manager wrote an end-of-archive block")
        self.assertTrue(tar.closed, "context manager failed")

    def test_eof(self):
        # __exit__() must write end-of-archive blocks, i.e. call
        # TarFile.close() if there was no error.
        with tarfile.open(tmpname, "w"):
            pass
        self.assertNotEqual(os.path.getsize(tmpname), 0,
                "context manager wrote no end-of-archive block")

    def test_fileobj(self):
        # Test that __exit__() did not close the external file
        # object.
        with open(tmpname, "wb") as fobj:
            try:
                with tarfile.open(fileobj=fobj, mode="w") as tar:
                    raise Exception
            except:
                pass
            self.assertFalse(fobj.closed, "external file object was closed")
            self.assertTrue(tar.closed, "context manager failed")


@unittest.skipIf(hasattr(os, "link"), "requires os.link to be missing")
class LinkEmulationTest(ReadTest, unittest.TestCase):

    # Test for issue #8741 regression. On platforms that do not support
    # symbolic or hard links tarfile tries to extract these types of members
    # as the regular files they point to.
    def _test_link_extraction(self, name):
        self.tar.extract(name, TEMPDIR)
        with open(os.path.join(TEMPDIR, name), "rb") as f:
            data = f.read()
        self.assertEqual(sha256sum(data), sha256_regtype)

    # See issues #1578269, #8879, and #17689 for some history on these skips
    @unittest.skipIf(hasattr(os.path, "islink"),
                     "Skip emulation - has os.path.islink but not os.link")
    def test_hardlink_extraction1(self):
        self._test_link_extraction("ustar/lnktype")

    @unittest.skipIf(hasattr(os.path, "islink"),
                     "Skip emulation - has os.path.islink but not os.link")
    def test_hardlink_extraction2(self):
        self._test_link_extraction("./ustar/linktest2/lnktype")

    @unittest.skipIf(hasattr(os, "symlink"),
                     "Skip emulation if symlink exists")
    def test_symlink_extraction1(self):
        self._test_link_extraction("ustar/symtype")

    @unittest.skipIf(hasattr(os, "symlink"),
                     "Skip emulation if symlink exists")
    def test_symlink_extraction2(self):
        self._test_link_extraction("./ustar/linktest2/symtype")


class Bz2PartialReadTest(Bz2Test, unittest.TestCase):
    # Issue5068: The _BZ2Proxy.read() method loops forever
    # on an empty or partial bzipped file.

    def _test_partial_input(self, mode):
        class MyBytesIO(io.BytesIO):
            hit_eof = False
            def read(self, n):
                if self.hit_eof:
                    raise AssertionError("infinite loop detected in "
                                         "tarfile.open()")
                self.hit_eof = self.tell() == len(self.getvalue())
                return super(MyBytesIO, self).read(n)
            def seek(self, *args):
                self.hit_eof = False
                return super(MyBytesIO, self).seek(*args)

        data = bz2.compress(tarfile.TarInfo("foo").tobuf())
        for x in range(len(data) + 1):
            try:
                tarfile.open(fileobj=MyBytesIO(data[:x]), mode=mode)
            except tarfile.ReadError:
                pass # we have no interest in ReadErrors

    def test_partial_input(self):
        self._test_partial_input("r")

    def test_partial_input_bz2(self):
        self._test_partial_input("r:bz2")


def root_is_uid_gid_0():
    try:
        import pwd, grp
    except ImportError:
        return False
    if pwd.getpwuid(0)[0] != 'root':
        return False
    if grp.getgrgid(0)[0] != 'root':
        return False
    return True


@unittest.skipUnless(hasattr(os, 'chown'), "missing os.chown")
@unittest.skipUnless(hasattr(os, 'geteuid'), "missing os.geteuid")
class NumericOwnerTest(unittest.TestCase):
    # mock the following:
    #  os.chown: so we can test what's being called
    #  os.chmod: so the modes are not actually changed. if they are, we can't
    #             delete the files/directories
    #  os.geteuid: so we can lie and say we're root (uid = 0)

    @staticmethod
    def _make_test_archive(filename_1, dirname_1, filename_2):
        # the file contents to write
        fobj = io.BytesIO(b"content")

        # create a tar file with a file, a directory, and a file within that
        #  directory. Assign various .uid/.gid values to them
        items = [(filename_1, 99, 98, tarfile.REGTYPE, fobj),
                 (dirname_1,  77, 76, tarfile.DIRTYPE, None),
                 (filename_2, 88, 87, tarfile.REGTYPE, fobj),
                 ]
        with tarfile.open(tmpname, 'w') as tarfl:
            for name, uid, gid, typ, contents in items:
                t = tarfile.TarInfo(name)
                t.uid = uid
                t.gid = gid
                t.uname = 'root'
                t.gname = 'root'
                t.type = typ
                tarfl.addfile(t, contents)

        # return the full pathname to the tar file
        return tmpname

    @staticmethod
    @contextmanager
    def _setup_test(mock_geteuid):
        mock_geteuid.return_value = 0  # lie and say we're root
        fname = 'numeric-owner-testfile'
        dirname = 'dir'

        # the names we want stored in the tarfile
        filename_1 = fname
        dirname_1 = dirname
        filename_2 = os.path.join(dirname, fname)

        # create the tarfile with the contents we're after
        tar_filename = NumericOwnerTest._make_test_archive(filename_1,
                                                           dirname_1,
                                                           filename_2)

        # open the tarfile for reading. yield it and the names of the items
        #  we stored into the file
        with tarfile.open(tar_filename) as tarfl:
            yield tarfl, filename_1, dirname_1, filename_2

    @unittest.mock.patch('os.chown')
    @unittest.mock.patch('os.chmod')
    @unittest.mock.patch('os.geteuid')
    def test_extract_with_numeric_owner(self, mock_geteuid, mock_chmod,
                                        mock_chown):
        with self._setup_test(mock_geteuid) as (tarfl, filename_1, _,
                                                filename_2):
            tarfl.extract(filename_1, TEMPDIR, numeric_owner=True)
            tarfl.extract(filename_2 , TEMPDIR, numeric_owner=True)

        # convert to filesystem paths
        f_filename_1 = os.path.join(TEMPDIR, filename_1)
        f_filename_2 = os.path.join(TEMPDIR, filename_2)

        mock_chown.assert_has_calls([unittest.mock.call(f_filename_1, 99, 98),
                                     unittest.mock.call(f_filename_2, 88, 87),
                                     ],
                                    any_order=True)

    @unittest.mock.patch('os.chown')
    @unittest.mock.patch('os.chmod')
    @unittest.mock.patch('os.geteuid')
    def test_extractall_with_numeric_owner(self, mock_geteuid, mock_chmod,
                                           mock_chown):
        with self._setup_test(mock_geteuid) as (tarfl, filename_1, dirname_1,
                                                filename_2):
            tarfl.extractall(TEMPDIR, numeric_owner=True)

        # convert to filesystem paths
        f_filename_1 = os.path.join(TEMPDIR, filename_1)
        f_dirname_1  = os.path.join(TEMPDIR, dirname_1)
        f_filename_2 = os.path.join(TEMPDIR, filename_2)

        mock_chown.assert_has_calls([unittest.mock.call(f_filename_1, 99, 98),
                                     unittest.mock.call(f_dirname_1, 77, 76),
                                     unittest.mock.call(f_filename_2, 88, 87),
                                     ],
                                    any_order=True)

    # this test requires that uid=0 and gid=0 really be named 'root'. that's
    #  because the uname and gname in the test file are 'root', and extract()
    #  will look them up using pwd and grp to find their uid and gid, which we
    #  test here to be 0.
    @unittest.skipUnless(root_is_uid_gid_0(),
                         'uid=0,gid=0 must be named "root"')
    @unittest.mock.patch('os.chown')
    @unittest.mock.patch('os.chmod')
    @unittest.mock.patch('os.geteuid')
    def test_extract_without_numeric_owner(self, mock_geteuid, mock_chmod,
                                           mock_chown):
        with self._setup_test(mock_geteuid) as (tarfl, filename_1, _, _):
            tarfl.extract(filename_1, TEMPDIR, numeric_owner=False)

        # convert to filesystem paths
        f_filename_1 = os.path.join(TEMPDIR, filename_1)

        mock_chown.assert_called_with(f_filename_1, 0, 0)

    @unittest.mock.patch('os.geteuid')
    def test_keyword_only(self, mock_geteuid):
        with self._setup_test(mock_geteuid) as (tarfl, filename_1, _, _):
            self.assertRaises(TypeError,
                              tarfl.extract, filename_1, TEMPDIR, False, True)


def setUpModule():
    os_helper.unlink(TEMPDIR)
    os.makedirs(TEMPDIR)

    global testtarnames
    testtarnames = [tarname]
    with open(tarname, "rb") as fobj:
        data = fobj.read()

    # Create compressed tarfiles.
    for c in GzipTest, Bz2Test, LzmaTest:
        if c.open:
            os_helper.unlink(c.tarname)
            testtarnames.append(c.tarname)
            with c.open(c.tarname, "wb") as tar:
                tar.write(data)

def tearDownModule():
    if os.path.exists(TEMPDIR):
        os_helper.rmtree(TEMPDIR)

if __name__ == "__main__":
    unittest.main()