aboutsummaryrefslogtreecommitdiffstats
path: root/libqpdf/QUtil.cc
blob: 58646ade4ff3df5f10d36d40c42a4bb8f21d04f9 (plain) (blame)
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
// Include qpdf-config.h first so off_t is guaranteed to have the right size.
#include <qpdf/qpdf-config.h>

#include <qpdf/QUtil.hh>
#include <qpdf/PointerHolder.hh>
#ifdef USE_INSECURE_RANDOM
# include <qpdf/InsecureRandomDataProvider.hh>
#endif
#include <qpdf/SecureRandomDataProvider.hh>
#include <qpdf/QPDFSystemError.hh>
#include <qpdf/QTC.hh>

#include <cmath>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <stdexcept>
#include <set>
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#ifdef _WIN32
#include <windows.h>
#include <direct.h>
#include <io.h>
#else
#include <unistd.h>
#include <sys/stat.h>
#endif

// First element is 128
static unsigned short pdf_doc_to_unicode[] = {
    0x2022,    // 0x80    BULLET
    0x2020,    // 0x81    DAGGER
    0x2021,    // 0x82    DOUBLE DAGGER
    0x2026,    // 0x83    HORIZONTAL ELLIPSIS
    0x2014,    // 0x84    EM DASH
    0x2013,    // 0x85    EN DASH
    0x0192,    // 0x86    SMALL LETTER F WITH HOOK
    0x2044,    // 0x87    FRACTION SLASH (solidus)
    0x2039,    // 0x88    SINGLE LEFT-POINTING ANGLE QUOTATION MARK
    0x203a,    // 0x89    SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
    0x2212,    // 0x8a    MINUS SIGN
    0x2030,    // 0x8b    PER MILLE SIGN
    0x201e,    // 0x8c    DOUBLE LOW-9 QUOTATION MARK (quotedblbase)
    0x201c,    // 0x8d    LEFT DOUBLE QUOTATION MARK (double quote left)
    0x201d,    // 0x8e    RIGHT DOUBLE QUOTATION MARK (quotedblright)
    0x2018,    // 0x8f    LEFT SINGLE QUOTATION MARK (quoteleft)
    0x2019,    // 0x90    RIGHT SINGLE QUOTATION MARK (quoteright)
    0x201a,    // 0x91    SINGLE LOW-9 QUOTATION MARK (quotesinglbase)
    0x2122,    // 0x92    TRADE MARK SIGN
    0xfb01,    // 0x93    LATIN SMALL LIGATURE FI
    0xfb02,    // 0x94    LATIN SMALL LIGATURE FL
    0x0141,    // 0x95    LATIN CAPITAL LETTER L WITH STROKE
    0x0152,    // 0x96    LATIN CAPITAL LIGATURE OE
    0x0160,    // 0x97    LATIN CAPITAL LETTER S WITH CARON
    0x0178,    // 0x98    LATIN CAPITAL LETTER Y WITH DIAERESIS
    0x017d,    // 0x99    LATIN CAPITAL LETTER Z WITH CARON
    0x0131,    // 0x9a    LATIN SMALL LETTER DOTLESS I
    0x0142,    // 0x9b    LATIN SMALL LETTER L WITH STROKE
    0x0153,    // 0x9c    LATIN SMALL LIGATURE OE
    0x0161,    // 0x9d    LATIN SMALL LETTER S WITH CARON
    0x017e,    // 0x9e    LATIN SMALL LETTER Z WITH CARON
    0xfffd,    // 0x9f    UNDEFINED
    0x20ac,    // 0xa0    EURO SIGN
};
static unsigned short win_ansi_to_unicode[] = {
    0x20ac,    // 0x80
    0xfffd,    // 0x81
    0x201a,    // 0x82
    0x0192,    // 0x83
    0x201e,    // 0x84
    0x2026,    // 0x85
    0x2020,    // 0x86
    0x2021,    // 0x87
    0x02c6,    // 0x88
    0x2030,    // 0x89
    0x0160,    // 0x8a
    0x2039,    // 0x8b
    0x0152,    // 0x8c
    0xfffd,    // 0x8d
    0x017d,    // 0x8e
    0xfffd,    // 0x8f
    0xfffd,    // 0x90
    0x2018,    // 0x91
    0x2019,    // 0x92
    0x201c,    // 0x93
    0x201d,    // 0x94
    0x2022,    // 0x95
    0x2013,    // 0x96
    0x2014,    // 0x97
    0x0303,    // 0x98
    0x2122,    // 0x99
    0x0161,    // 0x9a
    0x203a,    // 0x9b
    0x0153,    // 0x9c
    0xfffd,    // 0x9d
    0x017e,    // 0x9e
    0x0178,    // 0x9f
    0x00a0,    // 0xa0
};
static unsigned short mac_roman_to_unicode[] = {
    0x00c4,    // 0x80
    0x00c5,    // 0x81
    0x00c7,    // 0x82
    0x00c9,    // 0x83
    0x00d1,    // 0x84
    0x00d6,    // 0x85
    0x00dc,    // 0x86
    0x00e1,    // 0x87
    0x00e0,    // 0x88
    0x00e2,    // 0x89
    0x00e4,    // 0x8a
    0x00e3,    // 0x8b
    0x00e5,    // 0x8c
    0x00e7,    // 0x8d
    0x00e9,    // 0x8e
    0x00e8,    // 0x8f
    0x00ea,    // 0x90
    0x00eb,    // 0x91
    0x00ed,    // 0x92
    0x00ec,    // 0x93
    0x00ee,    // 0x94
    0x00ef,    // 0x95
    0x00f1,    // 0x96
    0x00f3,    // 0x97
    0x00f2,    // 0x98
    0x00f4,    // 0x99
    0x00f6,    // 0x9a
    0x00f5,    // 0x9b
    0x00fa,    // 0x9c
    0x00f9,    // 0x9d
    0x00fb,    // 0x9e
    0x00fc,    // 0x9f
    0x2020,    // 0xa0
    0x00b0,    // 0xa1
    0x00a2,    // 0xa2
    0x00a3,    // 0xa3
    0x00a7,    // 0xa4
    0x2022,    // 0xa5
    0x00b6,    // 0xa6
    0x00df,    // 0xa7
    0x00ae,    // 0xa8
    0x00a9,    // 0xa9
    0x2122,    // 0xaa
    0x0301,    // 0xab
    0x0308,    // 0xac
    0xfffd,    // 0xad
    0x00c6,    // 0xae
    0x00d8,    // 0xaf
    0xfffd,    // 0xb0
    0x00b1,    // 0xb1
    0xfffd,    // 0xb2
    0xfffd,    // 0xb3
    0x00a5,    // 0xb4
    0x03bc,    // 0xb5
    0xfffd,    // 0xb6
    0xfffd,    // 0xb7
    0xfffd,    // 0xb8
    0xfffd,    // 0xb9
    0xfffd,    // 0xba
    0x1d43,    // 0xbb
    0x1d52,    // 0xbc
    0xfffd,    // 0xbd
    0x00e6,    // 0xbe
    0x00f8,    // 0xbf
    0x00bf,    // 0xc0
    0x00a1,    // 0xc1
    0x00ac,    // 0xc2
    0xfffd,    // 0xc3
    0x0192,    // 0xc4
    0xfffd,    // 0xc5
    0xfffd,    // 0xc6
    0x00ab,    // 0xc7
    0x00bb,    // 0xc8
    0x2026,    // 0xc9
    0xfffd,    // 0xca
    0x00c0,    // 0xcb
    0x00c3,    // 0xcc
    0x00d5,    // 0xcd
    0x0152,    // 0xce
    0x0153,    // 0xcf
    0x2013,    // 0xd0
    0x2014,    // 0xd1
    0x201c,    // 0xd2
    0x201d,    // 0xd3
    0x2018,    // 0xd4
    0x2019,    // 0xd5
    0x00f7,    // 0xd6
    0xfffd,    // 0xd7
    0x00ff,    // 0xd8
    0x0178,    // 0xd9
    0x2044,    // 0xda
    0x00a4,    // 0xdb
    0x2039,    // 0xdc
    0x203a,    // 0xdd
    0xfb01,    // 0xde
    0xfb02,    // 0xdf
    0x2021,    // 0xe0
    0x00b7,    // 0xe1
    0x201a,    // 0xe2
    0x201e,    // 0xe3
    0x2030,    // 0xe4
    0x00c2,    // 0xe5
    0x00ca,    // 0xe6
    0x00c1,    // 0xe7
    0x00cb,    // 0xe8
    0x00c8,    // 0xe9
    0x00cd,    // 0xea
    0x00ce,    // 0xeb
    0x00cf,    // 0xec
    0x00cc,    // 0xed
    0x00d3,    // 0xee
    0x00d4,    // 0xef
    0xfffd,    // 0xf0
    0x00d2,    // 0xf1
    0x00da,    // 0xf2
    0x00db,    // 0xf3
    0x00d9,    // 0xf4
    0x0131,    // 0xf5
    0x02c6,    // 0xf6
    0x0303,    // 0xf7
    0x0304,    // 0xf8
    0x0306,    // 0xf9
    0x0307,    // 0xfa
    0x030a,    // 0xfb
    0x0327,    // 0xfc
    0x030b,    // 0xfd
    0x0328,    // 0xfe
    0x02c7,    // 0xff
};

std::string
QUtil::int_to_string(long long num, int length)
{
    return int_to_string_base(num, 10, length);
}

std::string
QUtil::int_to_string_base(long long num, int base, int length)
{
    // Backward compatibility -- int_to_string, which calls this
    // function, used to use sprintf with %0*d, so we interpret length
    // such that a negative value appends spaces and a positive value
    // prepends zeroes.
    if (! ((base == 8) || (base == 10) || (base == 16)))
    {
        throw std::logic_error(
            "int_to_string_base called with unsupported base");
    }
    std::ostringstream buf;
    buf << std::setbase(base) << std::nouppercase << num;
    std::string result;
    if ((length > 0) &&
        (buf.str().length() < static_cast<size_t>(length)))
    {
	result.append(length - buf.str().length(), '0');
    }
    result += buf.str();
    if ((length < 0) && (buf.str().length() < static_cast<size_t>(-length)))
    {
	result.append(-length - buf.str().length(), ' ');
    }
    return result;
}

std::string
QUtil::double_to_string(double num, int decimal_places)
{
    // Backward compatibility -- this code used to use sprintf and
    // treated decimal_places <= 0 to mean to use the default, which
    // was six decimal places.  Also sprintf with %*.f interprets the
    // length as fixed point rather than significant figures.
    if (decimal_places <= 0)
    {
        decimal_places = 6;
    }
    std::ostringstream buf;
    buf << std::setprecision(decimal_places) << std::fixed << num;
    return buf.str();
}

long long
QUtil::string_to_ll(char const* str)
{
    errno = 0;
#ifdef _MSC_VER
    long long result = _strtoi64(str, 0, 10);
#else
    long long result = strtoll(str, 0, 10);
#endif
    if (errno == ERANGE)
    {
        throw std::runtime_error(
            std::string("overflow/underflow converting ") + str
            + " to 64-bit integer");
    }
    return result;
}

int
QUtil::string_to_int(char const* str)
{
    errno = 0;
    long long_val = strtol(str, 0, 10);
    if (errno == ERANGE)
    {
        throw std::runtime_error(
            std::string("overflow/underflow converting ") + str
            + " to long integer");
    }
    int result = static_cast<int>(long_val);
    if (static_cast<long>(result) != long_val)
    {
        throw std::runtime_error(
            std::string("overflow/underflow converting ") + str
            + " to integer");
    }
    return result;
}

unsigned char*
QUtil::unsigned_char_pointer(std::string const& str)
{
    return reinterpret_cast<unsigned char*>(const_cast<char*>(str.c_str()));
}

unsigned char*
QUtil::unsigned_char_pointer(char const* str)
{
    return reinterpret_cast<unsigned char*>(const_cast<char*>(str));
}

void
QUtil::throw_system_error(std::string const& description)
{
    throw QPDFSystemError(description, errno);
}

int
QUtil::os_wrapper(std::string const& description, int status)
{
    if (status == -1)
    {
	throw_system_error(description);
    }
    return status;
}

FILE*
QUtil::safe_fopen(char const* filename, char const* mode)
{
    FILE* f = 0;
#ifdef _MSC_VER
    errno_t err = fopen_s(&f, filename, mode);
    if (err != 0)
    {
        errno = err;
        throw_system_error(std::string("open ") + filename);
    }
#else
    f = fopen_wrapper(std::string("open ") + filename, fopen(filename, mode));
#endif
    return f;
}

FILE*
QUtil::fopen_wrapper(std::string const& description, FILE* f)
{
    if (f == 0)
    {
	throw_system_error(description);
    }
    return f;
}

int
QUtil::seek(FILE* stream, qpdf_offset_t offset, int whence)
{
#if HAVE_FSEEKO
    return fseeko(stream, static_cast<off_t>(offset), whence);
#elif HAVE_FSEEKO64
    return fseeko64(stream, offset, whence);
#else
# if defined _MSC_VER || defined __BORLANDC__
    return _fseeki64(stream, offset, whence);
# else
    return fseek(stream, static_cast<long>(offset), whence);
# endif
#endif
}

qpdf_offset_t
QUtil::tell(FILE* stream)
{
#if HAVE_FSEEKO
    return static_cast<qpdf_offset_t>(ftello(stream));
#elif HAVE_FSEEKO64
    return static_cast<qpdf_offset_t>(ftello64(stream));
#else
# if defined _MSC_VER || defined __BORLANDC__
    return _ftelli64(stream);
# else
    return static_cast<qpdf_offset_t>(ftell(stream));
# endif
#endif
}

bool
QUtil::same_file(char const* name1, char const* name2)
{
    if ((name1 == 0) || (strlen(name1) == 0) ||
        (name2 == 0) || (strlen(name2) == 0))
    {
        return false;
    }
#ifdef _WIN32
    bool same = false;
# ifndef AVOID_WINDOWS_HANDLE
    HANDLE fh1 = CreateFile(name1, GENERIC_READ, FILE_SHARE_READ,
                            NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    HANDLE fh2 = CreateFile(name2, GENERIC_READ, FILE_SHARE_READ,
                            NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    BY_HANDLE_FILE_INFORMATION fi1;
    BY_HANDLE_FILE_INFORMATION fi2;
    if ((fh1 != INVALID_HANDLE_VALUE) &&
        (fh2 != INVALID_HANDLE_VALUE) &&
        GetFileInformationByHandle(fh1, &fi1) &&
        GetFileInformationByHandle(fh2, &fi2) &&
        (fi1.dwVolumeSerialNumber == fi2.dwVolumeSerialNumber) &&
        (fi1.nFileIndexLow == fi2.nFileIndexLow) &&
        (fi1.nFileIndexHigh == fi2.nFileIndexHigh))
    {
        same = true;
    }
    if (fh1 != INVALID_HANDLE_VALUE)
    {
        CloseHandle(fh1);
    }
    if (fh2 != INVALID_HANDLE_VALUE)
    {
        CloseHandle(fh2);
    }
# endif
    return same;
#else
    struct stat st1;
    struct stat st2;
    if ((stat(name1, &st1) == 0) &&
        (stat(name2, &st2) == 0) &&
        (st1.st_ino == st2.st_ino) &&
        (st1.st_dev == st2.st_dev))
    {
        return true;
    }
#endif
    return false;
}

char*
QUtil::copy_string(std::string const& str)
{
    char* result = new char[str.length() + 1];
    // Use memcpy in case string contains nulls
    result[str.length()] = '\0';
    memcpy(result, str.c_str(), str.length());
    return result;
}

std::string
QUtil::hex_encode(std::string const& input)
{
    std::string result;
    for (unsigned int i = 0; i < input.length(); ++i)
    {
        result += QUtil::int_to_string_base(
            static_cast<int>(static_cast<unsigned char>(input.at(i))), 16, 2);
    }
    return result;
}

std::string
QUtil::hex_decode(std::string const& input)
{
    std::string result;
    size_t pos = 0;
    for (std::string::const_iterator p = input.begin(); p != input.end(); ++p)
    {
        char ch = *p;
        bool skip = false;
        if ((*p >= 'A') && (*p <= 'F'))
        {
            ch -= 'A';
            ch += 10;
        }
        else if ((*p >= 'a') && (*p <= 'f'))
        {
            ch -= 'a';
            ch += 10;
        }
        else if ((*p >= '0') && (*p <= '9'))
        {
            ch -= '0';
        }
        else
        {
            skip = true;
        }
        if (! skip)
        {
            if (pos == 0)
            {
                result.push_back(ch << 4);
                pos = 1;
            }
            else
            {
                result[result.length()-1] += ch;
                pos = 0;
            }
        }
    }
    return result;
}

void
QUtil::binary_stdout()
{
#ifdef _WIN32
    _setmode(_fileno(stdout), _O_BINARY);
#endif
}

void
QUtil::binary_stdin()
{
#ifdef _WIN32
    _setmode(_fileno(stdin), _O_BINARY);
#endif
}

void
QUtil::setLineBuf(FILE* f)
{
#ifndef _WIN32
    setvbuf(f, reinterpret_cast<char *>(0), _IOLBF, 0);
#endif
}

char*
QUtil::getWhoami(char* argv0)
{
    char* whoami = 0;
    if (((whoami = strrchr(argv0, '/')) == NULL) &&
        ((whoami = strrchr(argv0, '\\')) == NULL))
    {
	whoami = argv0;
    }
    else
    {
	++whoami;
    }

    if ((strlen(whoami) > 4) &&
	(strcmp(whoami + strlen(whoami) - 4, ".exe") == 0))
    {
	whoami[strlen(whoami) - 4] = '\0';
    }

    return whoami;
}

bool
QUtil::get_env(std::string const& var, std::string* value)
{
    // This was basically ripped out of wxWindows.
#ifdef _WIN32
# ifdef NO_GET_ENVIRONMENT
    return false;
# else
    // first get the size of the buffer
    DWORD len = ::GetEnvironmentVariable(var.c_str(), NULL, 0);
    if (len == 0)
    {
        // this means that there is no such variable
        return false;
    }

    if (value)
    {
	char* t = new char[len + 1];
        ::GetEnvironmentVariable(var.c_str(), t, len);
	*value = t;
	delete [] t;
    }

    return true;
# endif
#else
    char* p = getenv(var.c_str());
    if (p == 0)
    {
        return false;
    }
    if (value)
    {
        *value = p;
    }

    return true;
#endif
}

time_t
QUtil::get_current_time()
{
#ifdef _WIN32
    // The procedure to get local time at this resolution comes from
    // the Microsoft documentation.  It says to convert a SYSTEMTIME
    // to a FILETIME, and to copy the FILETIME to a ULARGE_INTEGER.
    // The resulting number is the number of 100-nanosecond intervals
    // between January 1, 1601 and now.  POSIX threads wants a time
    // based on January 1, 1970, so we adjust by subtracting the
    // number of seconds in that time period from the result we get
    // here.
    SYSTEMTIME sysnow;
    GetSystemTime(&sysnow);
    FILETIME filenow;
    SystemTimeToFileTime(&sysnow, &filenow);
    ULARGE_INTEGER uinow;
    uinow.LowPart = filenow.dwLowDateTime;
    uinow.HighPart = filenow.dwHighDateTime;
    ULONGLONG now = uinow.QuadPart;
    return ((now / 10000000LL) - 11644473600LL);
#else
    return time(0);
#endif
}

std::string
QUtil::toUTF8(unsigned long uval)
{
    std::string result;

    // A UTF-8 encoding of a Unicode value is a single byte for
    // Unicode values <= 127.  For larger values, the first byte of
    // the UTF-8 encoding has '1' as each of its n highest bits and
    // '0' for its (n+1)th highest bit where n is the total number of
    // bytes required.  Subsequent bytes start with '10' and have the
    // remaining 6 bits free for encoding.  For example, an 11-bit
    // Unicode value can be stored in two bytes where the first is
    // 110zzzzz, the second is 10zzzzzz, and the z's represent the
    // remaining bits.

    if (uval > 0x7fffffff)
    {
	throw std::runtime_error("bounds error in QUtil::toUTF8");
    }
    else if (uval < 128)
    {
	result += static_cast<char>(uval);
    }
    else
    {
	unsigned char bytes[7];
	bytes[6] = '\0';
	unsigned char* cur_byte = &bytes[5];

	// maximum value that will fit in the current number of bytes
	unsigned char maxval = 0x3f; // six bits

	while (uval > maxval)
	{
	    // Assign low six bits plus 10000000 to lowest unused
	    // byte position, then shift
	    *cur_byte = static_cast<unsigned char>(0x80 + (uval & 0x3f));
	    uval >>= 6;
	    // Maximum that will fit in high byte now shrinks by one bit
	    maxval >>= 1;
	    // Slide to the left one byte
	    if (cur_byte <= bytes)
	    {
		throw std::logic_error("QUtil::toUTF8: overflow error");
	    }
	    --cur_byte;
	}
	// If maxval is k bits long, the high (7 - k) bits of the
	// resulting byte must be high.
	*cur_byte = static_cast<unsigned char>(
            (0xff - (1 + (maxval << 1))) + uval);

	result += reinterpret_cast<char*>(cur_byte);
    }

    return result;
}

std::string
QUtil::toUTF16(unsigned long uval)
{
    std::string result;
    if ((uval >= 0xd800) && (uval <= 0xdfff))
    {
        result = "\xff\xfd";
    }
    else if (uval <= 0xffff)
    {
        char out[2];
        out[0] = (uval & 0xff00) >> 8;
        out[1] = (uval & 0xff);
        result = std::string(out, 2);
    }
    else if (uval <= 0x10ffff)
    {
        char out[4];
        uval -= 0x10000;
        unsigned short high = ((uval & 0xffc00) >> 10) + 0xd800;
        unsigned short low = (uval & 0x3ff) + 0xdc00;
        out[0] = (high & 0xff00) >> 8;
        out[1] = (high & 0xff);
        out[2] = (low & 0xff00) >> 8;
        out[3] = (low & 0xff);
        result = std::string(out, 4);
    }
    else
    {
        result = "\xff\xfd";
    }

    return result;
}

// Random data support

long
QUtil::random()
{
    long result = 0L;
    initializeWithRandomBytes(
        reinterpret_cast<unsigned char*>(&result),
        sizeof(result));
    return result;
}

static RandomDataProvider* random_data_provider = 0;

#ifdef USE_INSECURE_RANDOM
static RandomDataProvider* insecure_random_data_provider =
    InsecureRandomDataProvider::getInstance();
#else
static RandomDataProvider* insecure_random_data_provider = 0;
#endif
static RandomDataProvider* secure_random_data_provider =
    SecureRandomDataProvider::getInstance();

static void
initialize_random_data_provider()
{
    if (random_data_provider == 0)
    {
        if (secure_random_data_provider)
        {
            random_data_provider = secure_random_data_provider;
        }
        else if (insecure_random_data_provider)
        {
            random_data_provider = insecure_random_data_provider;
        }
    }
    // QUtil.hh has comments indicating that getRandomDataProvider(),
    // which calls this method, never returns null.
    if (random_data_provider == 0)
    {
        throw std::logic_error("QPDF has no random data provider");
    }
}

void
QUtil::setRandomDataProvider(RandomDataProvider* p)
{
    random_data_provider = p;
}

RandomDataProvider*
QUtil::getRandomDataProvider()
{
    initialize_random_data_provider();
    return random_data_provider;
}

void
QUtil::initializeWithRandomBytes(unsigned char* data, size_t len)
{
    initialize_random_data_provider();
    random_data_provider->provideRandomData(data, len);
}

void
QUtil::srandom(unsigned int seed)
{
#ifdef HAVE_RANDOM
    ::srandom(seed);
#else
    srand(seed);
#endif
}

bool
QUtil::is_hex_digit(char ch)
{
    return (ch && (strchr("0123456789abcdefABCDEF", ch) != 0));
}

bool
QUtil::is_space(char ch)
{
    return (ch && (strchr(" \f\n\r\t\v", ch) != 0));
}

bool
QUtil::is_digit(char ch)
{
    return ((ch >= '0') && (ch <= '9'));
}

bool
QUtil::is_number(char const* p)
{
    // ^[\+\-]?(\.\d*|\d+(\.\d*)?)$
    if (! *p)
    {
        return false;
    }
    if ((*p == '-') || (*p == '+'))
    {
        ++p;
    }
    bool found_dot = false;
    bool found_digit = false;
    for (; *p; ++p)
    {
        if (*p == '.')
        {
            if (found_dot)
            {
                // only one dot
                return false;
            }
            found_dot = true;
        }
        else if (QUtil::is_digit(*p))
        {
            found_digit = true;
        }
        else
        {
            return false;
        }
    }
    return found_digit;
}

std::list<std::string>
QUtil::read_lines_from_file(char const* filename)
{
    std::ifstream in(filename, std::ios_base::binary);
    if (! in.is_open())
    {
        throw_system_error(std::string("open ") + filename);
    }
    std::list<std::string> lines = read_lines_from_file(in);
    in.close();
    return lines;
}

std::list<std::string>
QUtil::read_lines_from_file(std::istream& in)
{
    std::list<std::string> result;
    std::string* buf = 0;

    char c;
    while (in.get(c))
    {
	if (buf == 0)
	{
	    result.push_back("");
	    buf = &(result.back());
	    buf->reserve(80);
	}

	if (buf->capacity() == buf->size())
	{
	    buf->reserve(buf->capacity() * 2);
	}
	if (c == '\n')
	{
            // Remove any carriage return that preceded the
            // newline and discard the newline
            if ((! buf->empty()) && ((*(buf->rbegin())) == '\r'))
            {
                buf->erase(buf->length() - 1);
            }
	    buf = 0;
	}
	else
	{
	    buf->append(1, c);
	}
    }

    return result;
}

int
QUtil::strcasecmp(char const *s1, char const *s2)
{
#ifdef _WIN32
    return _stricmp(s1, s2);
#else
    return ::strcasecmp(s1, s2);
#endif
}

static int maybe_from_end(int num, bool from_end, int max)
{
    if (from_end)
    {
        if (num > max)
        {
            num = 0;
        }
        else
        {
            num = max + 1 - num;
        }
    }
    return num;
}

std::vector<int>
QUtil::parse_numrange(char const* range, int max)
{
    std::vector<int> result;
    char const* p = range;
    try
    {
        std::vector<int> work;
        static int const comma = -1;
        static int const dash = -2;

        enum { st_top,
               st_in_number,
               st_after_number } state = st_top;
        bool last_separator_was_dash = false;
        int cur_number = 0;
        bool from_end = false;
        while (*p)
        {
            char ch = *p;
            if (isdigit(ch))
            {
                if (! ((state == st_top) || (state == st_in_number)))
                {
                    throw std::runtime_error("digit not expected");
                }
                state = st_in_number;
                cur_number *= 10;
                cur_number += (ch - '0');
            }
            else if (ch == 'z')
            {
                // z represents max
                if (! (state == st_top))
                {
                    throw std::runtime_error("z not expected");
                }
                state = st_after_number;
                cur_number = max;
            }
            else if (ch == 'r')
            {
                if (! (state == st_top))
                {
                    throw std::runtime_error("r not expected");
                }
                state = st_in_number;
                from_end = true;
            }
            else if ((ch == ',') || (ch == '-'))
            {
                if (! ((state == st_in_number) || (state == st_after_number)))
                {
                    throw std::runtime_error("unexpected separator");
                }
                cur_number = maybe_from_end(cur_number, from_end, max);
                work.push_back(cur_number);
                cur_number = 0;
                from_end = false;
                if (ch == ',')
                {
                    state = st_top;
                    last_separator_was_dash = false;
                    work.push_back(comma);
                }
                else if (ch == '-')
                {
                    if (last_separator_was_dash)
                    {
                        throw std::runtime_error("unexpected dash");
                    }
                    state = st_top;
                    last_separator_was_dash = true;
                    work.push_back(dash);
                }
            }
            else
            {
                throw std::runtime_error("unexpected character");
            }
            ++p;
        }
        if ((state == st_in_number) || (state == st_after_number))
        {
            cur_number = maybe_from_end(cur_number, from_end, max);
            work.push_back(cur_number);
        }
        else
        {
            throw std::runtime_error("number expected");
        }

        p = 0;
        for (size_t i = 0; i < work.size(); i += 2)
        {
            int num = work.at(i);
            // max == 0 means we don't know the max and are just
            // testing for valid syntax.
            if ((max > 0) && ((num < 1) || (num > max)))
            {
                throw std::runtime_error(
                    "number " + QUtil::int_to_string(num) + " out of range");
            }
            if (i == 0)
            {
                result.push_back(work.at(i));
            }
            else
            {
                int separator = work.at(i-1);
                if (separator == comma)
                {
                    result.push_back(num);
                }
                else if (separator == dash)
                {
                    int lastnum = result.back();
                    if (num > lastnum)
                    {
                        for (int j = lastnum + 1; j <= num; ++j)
                        {
                            result.push_back(j);
                        }
                    }
                    else
                    {
                        for (int j = lastnum - 1; j >= num; --j)
                        {
                            result.push_back(j);
                        }
                    }
                }
                else
                {
                    throw std::logic_error(
                        "INTERNAL ERROR parsing numeric range");
                }
            }
        }
    }
    catch (std::runtime_error const& e)
    {
        std::string message;
        if (p)
        {
            message = "error at * in numeric range " +
                std::string(range, p - range) + "*" + p + ": " + e.what();
        }
        else
        {
            message = "error in numeric range " +
                std::string(range) + ": " + e.what();
        }
        throw std::runtime_error(message);
    }
    return result;
}

enum encoding_e { e_utf16, e_ascii, e_winansi, e_macroman, e_pdfdoc };

static unsigned char
encode_winansi(unsigned long codepoint)
{
    // Use this ugly switch statement to avoid a static, which is not
    // thread-safe.
    unsigned char ch = '\0';
    switch (codepoint)
    {
      case 0x20ac:
        ch = 0x80;
        break;
      case 0x201a:
        ch = 0x82;
        break;
      case 0x192:
        ch = 0x83;
        break;
      case 0x201e:
        ch = 0x84;
        break;
      case 0x2026:
        ch = 0x85;
        break;
      case 0x2020:
        ch = 0x86;
        break;
      case 0x2021:
        ch = 0x87;
        break;
      case 0x2c6:
        ch = 0x88;
        break;
      case 0x2030:
        ch = 0x89;
        break;
      case 0x160:
        ch = 0x8a;
        break;
      case 0x2039:
        ch = 0x8b;
        break;
      case 0x152:
        ch = 0x8c;
        break;
      case 0x17d:
        ch = 0x8e;
        break;
      case 0x2018:
        ch = 0x91;
        break;
      case 0x2019:
        ch = 0x92;
        break;
      case 0x201c:
        ch = 0x93;
        break;
      case 0x201d:
        ch = 0x94;
        break;
      case 0x2022:
        ch = 0x95;
        break;
      case 0x2013:
        ch = 0x96;
        break;
      case 0x2014:
        ch = 0x97;
        break;
      case 0x303:
        ch = 0x98;
        break;
      case 0x2122:
        ch = 0x99;
        break;
      case 0x161:
        ch = 0x9a;
        break;
      case 0x203a:
        ch = 0x9b;
        break;
      case 0x153:
        ch = 0x9c;
        break;
      case 0x17e:
        ch = 0x9e;
        break;
      case 0x178:
        ch = 0x9f;
        break;
      case 0xa0:
        ch = 0xa0;
        break;
      default:
        break;
    }
    return ch;
}

static unsigned char
encode_macroman(unsigned long codepoint)
{
    // Use this ugly switch statement to avoid a static, which is not
    // thread-safe.
    unsigned char ch = '\0';
    switch (codepoint)
    {
      case 0xc4:
        ch = 0x80;
        break;
      case 0xc5:
        ch = 0x81;
        break;
      case 0xc7:
        ch = 0x82;
        break;
      case 0xc9:
        ch = 0x83;
        break;
      case 0xd1:
        ch = 0x84;
        break;
      case 0xd6:
        ch = 0x85;
        break;
      case 0xdc:
        ch = 0x86;
        break;
      case 0xe1:
        ch = 0x87;
        break;
      case 0xe0:
        ch = 0x88;
        break;
      case 0xe2:
        ch = 0x89;
        break;
      case 0xe4:
        ch = 0x8a;
        break;
      case 0xe3:
        ch = 0x8b;
        break;
      case 0xe5:
        ch = 0x8c;
        break;
      case 0xe7:
        ch = 0x8d;
        break;
      case 0xe9:
        ch = 0x8e;
        break;
      case 0xe8:
        ch = 0x8f;
        break;
      case 0xea:
        ch = 0x90;
        break;
      case 0xeb:
        ch = 0x91;
        break;
      case 0xed:
        ch = 0x92;
        break;
      case 0xec:
        ch = 0x93;
        break;
      case 0xee:
        ch = 0x94;
        break;
      case 0xef:
        ch = 0x95;
        break;
      case 0xf1:
        ch = 0x96;
        break;
      case 0xf3:
        ch = 0x97;
        break;
      case 0xf2:
        ch = 0x98;
        break;
      case 0xf4:
        ch = 0x99;
        break;
      case 0xf6:
        ch = 0x9a;
        break;
      case 0xf5:
        ch = 0x9b;
        break;
      case 0xfa:
        ch = 0x9c;
        break;
      case 0xf9:
        ch = 0x9d;
        break;
      case 0xfb:
        ch = 0x9e;
        break;
      case 0xfc:
        ch = 0x9f;
        break;
      case 0x2020:
        ch = 0xa0;
        break;
      case 0xb0:
        ch = 0xa1;
        break;
      case 0xa2:
        ch = 0xa2;
        break;
      case 0xa3:
        ch = 0xa3;
        break;
      case 0xa7:
        ch = 0xa4;
        break;
      case 0x2022:
        ch = 0xa5;
        break;
      case 0xb6:
        ch = 0xa6;
        break;
      case 0xdf:
        ch = 0xa7;
        break;
      case 0xae:
        ch = 0xa8;
        break;
      case 0xa9:
        ch = 0xa9;
        break;
      case 0x2122:
        ch = 0xaa;
        break;
      case 0x301:
        ch = 0xab;
        break;
      case 0x308:
        ch = 0xac;
        break;
      case 0xc6:
        ch = 0xae;
        break;
      case 0xd8:
        ch = 0xaf;
        break;
      case 0xb1:
        ch = 0xb1;
        break;
      case 0xa5:
        ch = 0xb4;
        break;
      case 0x3bc:
        ch = 0xb5;
        break;
      case 0x1d43:
        ch = 0xbb;
        break;
      case 0x1d52:
        ch = 0xbc;
        break;
      case 0xe6:
        ch = 0xbe;
        break;
      case 0xf8:
        ch = 0xbf;
        break;
      case 0xbf:
        ch = 0xc0;
        break;
      case 0xa1:
        ch = 0xc1;
        break;
      case 0xac:
        ch = 0xc2;
        break;
      case 0x192:
        ch = 0xc4;
        break;
      case 0xab:
        ch = 0xc7;
        break;
      case 0xbb:
        ch = 0xc8;
        break;
      case 0x2026:
        ch = 0xc9;
        break;
      case 0xc0:
        ch = 0xcb;
        break;
      case 0xc3:
        ch = 0xcc;
        break;
      case 0xd5:
        ch = 0xcd;
        break;
      case 0x152:
        ch = 0xce;
        break;
      case 0x153:
        ch = 0xcf;
        break;
      case 0x2013:
        ch = 0xd0;
        break;
      case 0x2014:
        ch = 0xd1;
        break;
      case 0x201c:
        ch = 0xd2;
        break;
      case 0x201d:
        ch = 0xd3;
        break;
      case 0x2018:
        ch = 0xd4;
        break;
      case 0x2019:
        ch = 0xd5;
        break;
      case 0xf7:
        ch = 0xd6;
        break;
      case 0xff:
        ch = 0xd8;
        break;
      case 0x178:
        ch = 0xd9;
        break;
      case 0x2044:
        ch = 0xda;
        break;
      case 0xa4:
        ch = 0xdb;
        break;
      case 0x2039:
        ch = 0xdc;
        break;
      case 0x203a:
        ch = 0xdd;
        break;
      case 0xfb01:
        ch = 0xde;
        break;
      case 0xfb02:
        ch = 0xdf;
        break;
      case 0x2021:
        ch = 0xe0;
        break;
      case 0xb7:
        ch = 0xe1;
        break;
      case 0x201a:
        ch = 0xe2;
        break;
      case 0x201e:
        ch = 0xe3;
        break;
      case 0x2030:
        ch = 0xe4;
        break;
      case 0xc2:
        ch = 0xe5;
        break;
      case 0xca:
        ch = 0xe6;
        break;
      case 0xc1:
        ch = 0xe7;
        break;
      case 0xcb:
        ch = 0xe8;
        break;
      case 0xc8:
        ch = 0xe9;
        break;
      case 0xcd:
        ch = 0xea;
        break;
      case 0xce:
        ch = 0xeb;
        break;
      case 0xcf:
        ch = 0xec;
        break;
      case 0xcc:
        ch = 0xed;
        break;
      case 0xd3:
        ch = 0xee;
        break;
      case 0xd4:
        ch = 0xef;
        break;
      case 0xd2:
        ch = 0xf1;
        break;
      case 0xda:
        ch = 0xf2;
        break;
      case 0xdb:
        ch = 0xf3;
        break;
      case 0xd9:
        ch = 0xf4;
        break;
      case 0x131:
        ch = 0xf5;
        break;
      case 0x2c6:
        ch = 0xf6;
        break;
      case 0x303:
        ch = 0xf7;
        break;
      case 0x304:
        ch = 0xf8;
        break;
      case 0x306:
        ch = 0xf9;
        break;
      case 0x307:
        ch = 0xfa;
        break;
      case 0x30a:
        ch = 0xfb;
        break;
      case 0x327:
        ch = 0xfc;
        break;
      case 0x30b:
        ch = 0xfd;
        break;
      case 0x328:
        ch = 0xfe;
        break;
      case 0x2c7:
        ch = 0xff;
        break;
      default:
        break;
    }
    return ch;
}

static unsigned char
encode_pdfdoc(unsigned long codepoint)
{
    // Use this ugly switch statement to avoid a static, which is not
    // thread-safe.
    unsigned char ch = '\0';
    switch (codepoint)
    {
      case 0x2022:
        ch = 0x80;
        break;
      case 0x2020:
        ch = 0x81;
        break;
      case 0x2021:
        ch = 0x82;
        break;
      case 0x2026:
        ch = 0x83;
        break;
      case 0x2014:
        ch = 0x84;
        break;
      case 0x2013:
        ch = 0x85;
        break;
      case 0x0192:
        ch = 0x86;
        break;
      case 0x2044:
        ch = 0x87;
        break;
      case 0x2039:
        ch = 0x88;
        break;
      case 0x203a:
        ch = 0x89;
        break;
      case 0x2212:
        ch = 0x8a;
        break;
      case 0x2030:
        ch = 0x8b;
        break;
      case 0x201e:
        ch = 0x8c;
        break;
      case 0x201c:
        ch = 0x8d;
        break;
      case 0x201d:
        ch = 0x8e;
        break;
      case 0x2018:
        ch = 0x8f;
        break;
      case 0x2019:
        ch = 0x90;
        break;
      case 0x201a:
        ch = 0x91;
        break;
      case 0x2122:
        ch = 0x92;
        break;
      case 0xfb01:
        ch = 0x93;
        break;
      case 0xfb02:
        ch = 0x94;
        break;
      case 0x0141:
        ch = 0x95;
        break;
      case 0x0152:
        ch = 0x96;
        break;
      case 0x0160:
        ch = 0x97;
        break;
      case 0x0178:
        ch = 0x98;
        break;
      case 0x017d:
        ch = 0x99;
        break;
      case 0x0131:
        ch = 0x9a;
        break;
      case 0x0142:
        ch = 0x9b;
        break;
      case 0x0153:
        ch = 0x9c;
        break;
      case 0x0161:
        ch = 0x9d;
        break;
      case 0x017e:
        ch = 0x9e;
        break;
      case 0xfffd:
        ch = 0x9f;
        break;
      case 0x20ac:
        ch = 0xa0;
        break;
      default:
        break;
    }
    return ch;
}

unsigned long get_next_utf8_codepoint(
    std::string const& utf8_val, size_t& pos, bool& error)
{
    size_t len = utf8_val.length();
    unsigned char ch = static_cast<unsigned char>(utf8_val.at(pos));
    error = false;
    if (ch < 128)
    {
        return static_cast<unsigned long>(ch);
    }

    size_t bytes_needed = 0;
    unsigned bit_check = 0x40;
    unsigned char to_clear = 0x80;
    while (ch & bit_check)
    {
        ++bytes_needed;
        to_clear |= bit_check;
        bit_check >>= 1;
    }
    if (((bytes_needed > 5) || (bytes_needed < 1)) ||
        ((pos + bytes_needed) >= len))
    {
        error = true;
        return 0xfffd;
    }

    unsigned long codepoint = (ch & ~to_clear);
    while (bytes_needed > 0)
    {
        --bytes_needed;
        ch = utf8_val.at(++pos);
        if ((ch & 0xc0) != 0x80)
        {
            --pos;
            codepoint = 0xfffd;
            break;
        }
        codepoint <<= 6;
        codepoint += (ch & 0x3f);
    }
    return codepoint;
}

static bool
transcode_utf8(std::string const& utf8_val, std::string& result,
               encoding_e encoding, char unknown)
{
    bool okay = true;
    result.clear();
    if (encoding == e_utf16)
    {
        result += "\xfe\xff";
    }
    size_t len = utf8_val.length();
    for (size_t i = 0; i < len; ++i)
    {
        bool error = false;
        unsigned long codepoint = get_next_utf8_codepoint(utf8_val, i, error);
        if (error)
        {
            okay = false;
            if (encoding == e_utf16)
            {
                result += "\xff\xfd";
            }
            else
            {
                result.append(1, unknown);
            }
        }
        else if (codepoint < 128)
        {
            char ch = static_cast<char>(codepoint);
            if (encoding == e_utf16)
            {
                result += QUtil::toUTF16(ch);
            }
            else
            {
                result.append(1, ch);
            }
        }
        else if (encoding == e_utf16)
        {
            result += QUtil::toUTF16(codepoint);
        }
        else if ((codepoint > 160) && (codepoint < 256) &&
                 ((encoding == e_winansi) || (encoding == e_pdfdoc)))
        {
            result.append(1, static_cast<unsigned char>(codepoint & 0xff));
        }
        else
        {
            unsigned char ch = '\0';
            if (encoding == e_winansi)
            {
                ch = encode_winansi(codepoint);
            }
            else if (encoding == e_macroman)
            {
                ch = encode_macroman(codepoint);
            }
            else if (encoding == e_pdfdoc)
            {
                ch = encode_pdfdoc(codepoint);
            }
            if (ch == '\0')
            {
                okay = false;
                ch = static_cast<unsigned char>(unknown);
            }
            result.append(1, ch);
        }
    }
    return okay;
}

static std::string
transcode_utf8(std::string const& utf8_val, encoding_e encoding,
               char unknown)
{
    std::string result;
    transcode_utf8(utf8_val, result, encoding, unknown);
    return result;
}

std::string
QUtil::utf8_to_utf16(std::string const& utf8)
{
    return transcode_utf8(utf8, e_utf16, 0);
}

std::string
QUtil::utf8_to_ascii(std::string const& utf8, char unknown_char)
{
    return transcode_utf8(utf8, e_ascii, unknown_char);
}

std::string
QUtil::utf8_to_win_ansi(std::string const& utf8, char unknown_char)
{
    return transcode_utf8(utf8, e_winansi, unknown_char);
}

std::string
QUtil::utf8_to_mac_roman(std::string const& utf8, char unknown_char)
{
    return transcode_utf8(utf8, e_macroman, unknown_char);
}

std::string
QUtil::utf8_to_pdf_doc(std::string const& utf8, char unknown_char)
{
    return transcode_utf8(utf8, e_pdfdoc, unknown_char);
}

bool
QUtil::utf8_to_ascii(std::string const& utf8, std::string& ascii,
                     char unknown_char)
{
    return transcode_utf8(utf8, ascii, e_ascii, unknown_char);
}

bool
QUtil::utf8_to_win_ansi(std::string const& utf8, std::string& win,
                        char unknown_char)
{
    return transcode_utf8(utf8, win, e_winansi, unknown_char);
}

bool
QUtil::utf8_to_mac_roman(std::string const& utf8, std::string& mac,
                         char unknown_char)
{
    return transcode_utf8(utf8, mac, e_macroman, unknown_char);
}

bool
QUtil::utf8_to_pdf_doc(std::string const& utf8, std::string& pdfdoc,
                       char unknown_char)
{
    return transcode_utf8(utf8, pdfdoc, e_pdfdoc, unknown_char);
}

bool
QUtil::is_utf16(std::string const& val)
{
    return ((val.length() >= 2) &&
            (val.at(0) == '\xfe') && (val.at(1) == '\xff'));
}

std::string
QUtil::utf16_to_utf8(std::string const& val)
{
    std::string result;
    // This code uses unsigned long and unsigned short to hold
    // codepoint values. It requires unsigned long to be at least
    // 32 bits and unsigned short to be at least 16 bits, but it
    // will work fine if they are larger.
    unsigned long codepoint = 0L;
    size_t len = val.length();
    size_t start = 0;
    if (is_utf16(val))
    {
        start += 2;
    }
    // If the string has an odd number of bytes, the last byte is
    // ignored.
    for (unsigned int i = start; i < len; i += 2)
    {
        // Convert from UTF16-BE.  If we get a malformed
        // codepoint, this code will generate incorrect output
        // without giving a warning.  Specifically, a high
        // codepoint not followed by a low codepoint will be
        // discarded, and a low codepoint not preceded by a high
        // codepoint will just get its low 10 bits output.
        unsigned short bits =
            (static_cast<unsigned char>(val.at(i)) << 8) +
            static_cast<unsigned char>(val.at(i+1));
        if ((bits & 0xFC00) == 0xD800)
        {
            codepoint = 0x10000 + ((bits & 0x3FF) << 10);
            continue;
        }
        else if ((bits & 0xFC00) == 0xDC00)
        {
            if (codepoint != 0)
            {
                QTC::TC("qpdf", "QUtil non-trivial UTF-16");
            }
            codepoint += bits & 0x3FF;
        }
        else
        {
            codepoint = bits;
        }

        result += QUtil::toUTF8(codepoint);
        codepoint = 0;
    }
    return result;
}

std::string
QUtil::win_ansi_to_utf8(std::string const& val)
{
    std::string result;
    size_t len = val.length();
    for (unsigned int i = 0; i < len; ++i)
    {
        unsigned char ch = static_cast<unsigned char>(val.at(i));
        unsigned short val = ch;
        if ((ch >= 128) && (ch <= 160))
        {
            val = win_ansi_to_unicode[ch - 128];
        }
        result += QUtil::toUTF8(val);
    }
    return result;
}

std::string
QUtil::mac_roman_to_utf8(std::string const& val)
{
    std::string result;
    size_t len = val.length();
    for (unsigned int i = 0; i < len; ++i)
    {
        unsigned char ch = static_cast<unsigned char>(val.at(i));
        unsigned short val = ch;
        if (ch >= 128)
        {
            val = mac_roman_to_unicode[ch - 128];
        }
        result += QUtil::toUTF8(val);
    }
    return result;
}

std::string
QUtil::pdf_doc_to_utf8(std::string const& val)
{
    std::string result;
    size_t len = val.length();
    for (unsigned int i = 0; i < len; ++i)
    {
        unsigned char ch = static_cast<unsigned char>(val.at(i));
        unsigned short val = ch;
        if ((ch >= 128) && (ch <= 160))
        {
            val = pdf_doc_to_unicode[ch - 128];
        }
        result += QUtil::toUTF8(val);
    }
    return result;
}

void
QUtil::analyze_encoding(std::string const& val,
                        bool& has_8bit_chars,
                        bool& is_valid_utf8,
                        bool& is_utf16)
{
    has_8bit_chars = is_utf16 = is_valid_utf8 = false;
    if (QUtil::is_utf16(val))
    {
        has_8bit_chars = true;
        is_utf16 = true;
        return;
    }
    size_t len = val.length();
    bool any_errors = false;
    for (size_t i = 0; i < len; ++i)
    {
        bool error = false;
        unsigned long codepoint = get_next_utf8_codepoint(val, i, error);
        if (error)
        {
            any_errors = true;
        }
        if (codepoint >= 128)
        {
            has_8bit_chars = true;
        }
    }
    if (has_8bit_chars && (! any_errors))
    {
        is_valid_utf8 = true;
    }
}

std::vector<std::string>
QUtil::possible_repaired_encodings(std::string supplied)
{
    std::vector<std::string> result;
    // Always include the original string
    result.push_back(supplied);
    bool has_8bit_chars = false;
    bool is_valid_utf8 = false;
    bool is_utf16 = false;
    analyze_encoding(supplied, has_8bit_chars, is_valid_utf8, is_utf16);
    if (! has_8bit_chars)
    {
        return result;
    }
    if (is_utf16)
    {
        // Convert to UTF-8 and pretend we got a UTF-8 string.
        is_utf16 = false;
        is_valid_utf8 = true;
        supplied = utf16_to_utf8(supplied);
    }
    std::string output;
    if (is_valid_utf8)
    {
        // Maybe we were given UTF-8 but wanted one of the single-byte
        // encodings.
        if (utf8_to_pdf_doc(supplied, output))
        {
            result.push_back(output);
        }
        if (utf8_to_win_ansi(supplied, output))
        {
            result.push_back(output);
        }
        if (utf8_to_mac_roman(supplied, output))
        {
            result.push_back(output);
        }
    }
    else
    {
        // Maybe we were given one of the single-byte encodings but
        // wanted UTF-8.
        std::string from_pdf_doc(pdf_doc_to_utf8(supplied));
        result.push_back(from_pdf_doc);
        std::string from_win_ansi(win_ansi_to_utf8(supplied));
        result.push_back(from_win_ansi);
        std::string from_mac_roman(mac_roman_to_utf8(supplied));
        result.push_back(from_mac_roman);

        // Maybe we were given one of the other single-byte encodings
        // but wanted one of the other ones.
        if (utf8_to_win_ansi(from_pdf_doc, output))
        {
            result.push_back(output);
        }
        if (utf8_to_mac_roman(from_pdf_doc, output))
        {
            result.push_back(output);
        }
        if (utf8_to_pdf_doc(from_win_ansi, output))
        {
            result.push_back(output);
        }
        if (utf8_to_mac_roman(from_win_ansi, output))
        {
            result.push_back(output);
        }
        if (utf8_to_pdf_doc(from_mac_roman, output))
        {
            result.push_back(output);
        }
        if (utf8_to_win_ansi(from_mac_roman, output))
        {
            result.push_back(output);
        }
    }
    // De-duplicate
    std::vector<std::string> t;
    std::set<std::string> seen;
    for (std::vector<std::string>::iterator iter = result.begin();
         iter != result.end(); ++iter)
    {
        if (! seen.count(*iter))
        {
            seen.insert(*iter);
            t.push_back(*iter);
        }
    }
    return t;
}