summaryrefslogtreecommitdiff
path: root/lib/striconveh.c
blob: 2a9a8f723254323fcfbd41cc3d3bbac5b029d8ce (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
/* Character set conversion with error handling.
   Copyright (C) 2001-2015 Free Software Foundation, Inc.
   Written by Bruno Haible and Simon Josefsson.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include "striconveh.h"

#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#if HAVE_ICONV
# include <iconv.h>
# include "unistr.h"
#endif

#include "c-strcase.h"
#include "c-strcaseeq.h"

#ifndef SIZE_MAX
# define SIZE_MAX ((size_t) -1)
#endif


#if HAVE_ICONV

/* The caller must provide an iconveh_t, not just an iconv_t, because when a
   conversion error occurs, we may have to determine the Unicode representation
   of the inconvertible character.  */

int
iconveh_open (const char *to_codeset, const char *from_codeset, iconveh_t *cdp)
{
  iconv_t cd;
  iconv_t cd1;
  iconv_t cd2;

  /* Avoid glibc-2.1 bug with EUC-KR.  */
# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
     && !defined _LIBICONV_VERSION
  if (c_strcasecmp (from_codeset, "EUC-KR") == 0
      || c_strcasecmp (to_codeset, "EUC-KR") == 0)
    {
      errno = EINVAL;
      return -1;
    }
# endif

  cd = iconv_open (to_codeset, from_codeset);

  if (STRCASEEQ (from_codeset, "UTF-8", 'U','T','F','-','8',0,0,0,0))
    cd1 = (iconv_t)(-1);
  else
    {
      cd1 = iconv_open ("UTF-8", from_codeset);
      if (cd1 == (iconv_t)(-1))
        {
          int saved_errno = errno;
          if (cd != (iconv_t)(-1))
            iconv_close (cdp->cd);
          errno = saved_errno;
          return -1;
        }
    }

  if (STRCASEEQ (to_codeset, "UTF-8", 'U','T','F','-','8',0,0,0,0)
# if (((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2) || __GLIBC__ > 2) \
      && !defined __UCLIBC__) \
     || _LIBICONV_VERSION >= 0x0105
      || c_strcasecmp (to_codeset, "UTF-8//TRANSLIT") == 0
# endif
     )
    cd2 = (iconv_t)(-1);
  else
    {
      cd2 = iconv_open (to_codeset, "UTF-8");
      if (cd2 == (iconv_t)(-1))
        {
          int saved_errno = errno;
          if (cd1 != (iconv_t)(-1))
            iconv_close (cd1);
          if (cd != (iconv_t)(-1))
            iconv_close (cd);
          errno = saved_errno;
          return -1;
        }
    }

  cdp->cd = cd;
  cdp->cd1 = cd1;
  cdp->cd2 = cd2;
  return 0;
}

int
iconveh_close (const iconveh_t *cd)
{
  if (cd->cd2 != (iconv_t)(-1) && iconv_close (cd->cd2) < 0)
    {
      /* Return -1, but preserve the errno from iconv_close.  */
      int saved_errno = errno;
      if (cd->cd1 != (iconv_t)(-1))
        iconv_close (cd->cd1);
      if (cd->cd != (iconv_t)(-1))
        iconv_close (cd->cd);
      errno = saved_errno;
      return -1;
    }
  if (cd->cd1 != (iconv_t)(-1) && iconv_close (cd->cd1) < 0)
    {
      /* Return -1, but preserve the errno from iconv_close.  */
      int saved_errno = errno;
      if (cd->cd != (iconv_t)(-1))
        iconv_close (cd->cd);
      errno = saved_errno;
      return -1;
    }
  if (cd->cd != (iconv_t)(-1) && iconv_close (cd->cd) < 0)
    return -1;
  return 0;
}

/* iconv_carefully is like iconv, except that it stops as soon as it encounters
   a conversion error, and it returns in *INCREMENTED a boolean telling whether
   it has incremented the input pointers past the error location.  */
# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__)
/* Irix iconv() inserts a NUL byte if it cannot convert.
   NetBSD iconv() inserts a question mark if it cannot convert.
   Only GNU libiconv and GNU libc are known to prefer to fail rather
   than doing a lossy conversion.  */
static size_t
iconv_carefully (iconv_t cd,
                 const char **inbuf, size_t *inbytesleft,
                 char **outbuf, size_t *outbytesleft,
                 bool *incremented)
{
  const char *inptr = *inbuf;
  const char *inptr_end = inptr + *inbytesleft;
  char *outptr = *outbuf;
  size_t outsize = *outbytesleft;
  const char *inptr_before;
  size_t res;

  do
    {
      size_t insize;

      inptr_before = inptr;
      res = (size_t)(-1);

      for (insize = 1; inptr + insize <= inptr_end; insize++)
        {
          res = iconv (cd,
                       (ICONV_CONST char **) &inptr, &insize,
                       &outptr, &outsize);
          if (!(res == (size_t)(-1) && errno == EINVAL))
            break;
          /* iconv can eat up a shift sequence but give EINVAL while attempting
             to convert the first character.  E.g. libiconv does this.  */
          if (inptr > inptr_before)
            {
              res = 0;
              break;
            }
        }

      if (res == 0)
        {
          *outbuf = outptr;
          *outbytesleft = outsize;
        }
    }
  while (res == 0 && inptr < inptr_end);

  *inbuf = inptr;
  *inbytesleft = inptr_end - inptr;
  if (res != (size_t)(-1) && res > 0)
    {
      /* iconv() has already incremented INPTR.  We cannot go back to a
         previous INPTR, otherwise the state inside CD would become invalid,
         if FROM_CODESET is a stateful encoding.  So, tell the caller that
         *INBUF has already been incremented.  */
      *incremented = (inptr > inptr_before);
      errno = EILSEQ;
      return (size_t)(-1);
    }
  else
    {
      *incremented = false;
      return res;
    }
}
# else
#  define iconv_carefully(cd, inbuf, inbytesleft, outbuf, outbytesleft, incremented) \
     (*(incremented) = false, \
      iconv (cd, (ICONV_CONST char **) (inbuf), inbytesleft, outbuf, outbytesleft))
# endif

/* iconv_carefully_1 is like iconv_carefully, except that it stops after
   converting one character or one shift sequence.  */
static size_t
iconv_carefully_1 (iconv_t cd,
                   const char **inbuf, size_t *inbytesleft,
                   char **outbuf, size_t *outbytesleft,
                   bool *incremented)
{
  const char *inptr_before = *inbuf;
  const char *inptr = inptr_before;
  const char *inptr_end = inptr_before + *inbytesleft;
  char *outptr = *outbuf;
  size_t outsize = *outbytesleft;
  size_t res = (size_t)(-1);
  size_t insize;

  for (insize = 1; inptr_before + insize <= inptr_end; insize++)
    {
      inptr = inptr_before;
      res = iconv (cd,
                   (ICONV_CONST char **) &inptr, &insize,
                   &outptr, &outsize);
      if (!(res == (size_t)(-1) && errno == EINVAL))
        break;
      /* iconv can eat up a shift sequence but give EINVAL while attempting
         to convert the first character.  E.g. libiconv does this.  */
      if (inptr > inptr_before)
        {
          res = 0;
          break;
        }
    }

  *inbuf = inptr;
  *inbytesleft = inptr_end - inptr;
# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__)
  /* Irix iconv() inserts a NUL byte if it cannot convert.
     NetBSD iconv() inserts a question mark if it cannot convert.
     Only GNU libiconv and GNU libc are known to prefer to fail rather
     than doing a lossy conversion.  */
  if (res != (size_t)(-1) && res > 0)
    {
      /* iconv() has already incremented INPTR.  We cannot go back to a
         previous INPTR, otherwise the state inside CD would become invalid,
         if FROM_CODESET is a stateful encoding.  So, tell the caller that
         *INBUF has already been incremented.  */
      *incremented = (inptr > inptr_before);
      errno = EILSEQ;
      return (size_t)(-1);
    }
# endif

  if (res != (size_t)(-1))
    {
      *outbuf = outptr;
      *outbytesleft = outsize;
    }
  *incremented = false;
  return res;
}

/* utf8conv_carefully is like iconv, except that
     - it converts from UTF-8 to UTF-8,
     - it stops as soon as it encounters a conversion error, and it returns
       in *INCREMENTED a boolean telling whether it has incremented the input
       pointers past the error location,
     - if one_character_only is true, it stops after converting one
       character.  */
static size_t
utf8conv_carefully (bool one_character_only,
                    const char **inbuf, size_t *inbytesleft,
                    char **outbuf, size_t *outbytesleft,
                    bool *incremented)
{
  const char *inptr = *inbuf;
  size_t insize = *inbytesleft;
  char *outptr = *outbuf;
  size_t outsize = *outbytesleft;
  size_t res;

  res = 0;
  do
    {
      ucs4_t uc;
      int n;
      int m;

      n = u8_mbtoucr (&uc, (const uint8_t *) inptr, insize);
      if (n < 0)
        {
          errno = (n == -2 ? EINVAL : EILSEQ);
          n = u8_mbtouc (&uc, (const uint8_t *) inptr, insize);
          inptr += n;
          insize -= n;
          res = (size_t)(-1);
          *incremented = true;
          break;
        }
      if (outsize == 0)
        {
          errno = E2BIG;
          res = (size_t)(-1);
          *incremented = false;
          break;
        }
      m = u8_uctomb ((uint8_t *) outptr, uc, outsize);
      if (m == -2)
        {
          errno = E2BIG;
          res = (size_t)(-1);
          *incremented = false;
          break;
        }
      inptr += n;
      insize -= n;
      if (m == -1)
        {
          errno = EILSEQ;
          res = (size_t)(-1);
          *incremented = true;
          break;
        }
      outptr += m;
      outsize -= m;
    }
  while (!one_character_only && insize > 0);

  *inbuf = inptr;
  *inbytesleft = insize;
  *outbuf = outptr;
  *outbytesleft = outsize;
  return res;
}

static int
mem_cd_iconveh_internal (const char *src, size_t srclen,
                         iconv_t cd, iconv_t cd1, iconv_t cd2,
                         enum iconv_ilseq_handler handler,
                         size_t extra_alloc,
                         size_t *offsets,
                         char **resultp, size_t *lengthp)
{
  /* When a conversion error occurs, we cannot start using CD1 and CD2 at
     this point: FROM_CODESET may be a stateful encoding like ISO-2022-KR.
     Instead, we have to start afresh from the beginning of SRC.  */
  /* Use a temporary buffer, so that for small strings, a single malloc()
     call will be sufficient.  */
# define tmpbufsize 4096
  /* The alignment is needed when converting e.g. to glibc's WCHAR_T or
     libiconv's UCS-4-INTERNAL encoding.  */
  union { unsigned int align; char buf[tmpbufsize]; } tmp;
# define tmpbuf tmp.buf

  char *initial_result;
  char *result;
  size_t allocated;
  size_t length;
  size_t last_length = (size_t)(-1); /* only needed if offsets != NULL */

  if (*resultp != NULL && *lengthp >= sizeof (tmpbuf))
    {
      initial_result = *resultp;
      allocated = *lengthp;
    }
  else
    {
      initial_result = tmpbuf;
      allocated = sizeof (tmpbuf);
    }
  result = initial_result;

  /* Test whether a direct conversion is possible at all.  */
  if (cd == (iconv_t)(-1))
    goto indirectly;

  if (offsets != NULL)
    {
      size_t i;

      for (i = 0; i < srclen; i++)
        offsets[i] = (size_t)(-1);

      last_length = (size_t)(-1);
    }
  length = 0;

  /* First, try a direct conversion, and see whether a conversion error
     occurs at all.  */
  {
    const char *inptr = src;
    size_t insize = srclen;

    /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug.  */
# if defined _LIBICONV_VERSION \
     || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
          || defined __sun)
    /* Set to the initial state.  */
    iconv (cd, NULL, NULL, NULL, NULL);
# endif

    while (insize > 0)
      {
        char *outptr = result + length;
        size_t outsize = allocated - extra_alloc - length;
        bool incremented;
        size_t res;
        bool grow;

        if (offsets != NULL)
          {
            if (length != last_length) /* ensure that offset[] be increasing */
              {
                offsets[inptr - src] = length;
                last_length = length;
              }
            res = iconv_carefully_1 (cd,
                                     &inptr, &insize,
                                     &outptr, &outsize,
                                     &incremented);
          }
        else
          /* Use iconv_carefully instead of iconv here, because:
             - If TO_CODESET is UTF-8, we can do the error handling in this
               loop, no need for a second loop,
             - With iconv() implementations other than GNU libiconv and GNU
               libc, if we use iconv() in a big swoop, checking for an E2BIG
               return, we lose the number of irreversible conversions.  */
          res = iconv_carefully (cd,
                                 &inptr, &insize,
                                 &outptr, &outsize,
                                 &incremented);

        length = outptr - result;
        grow = (length + extra_alloc > allocated / 2);
        if (res == (size_t)(-1))
          {
            if (errno == E2BIG)
              grow = true;
            else if (errno == EINVAL)
              break;
            else if (errno == EILSEQ && handler != iconveh_error)
              {
                if (cd2 == (iconv_t)(-1))
                  {
                    /* TO_CODESET is UTF-8.  */
                    /* Error handling can produce up to 1 byte of output.  */
                    if (length + 1 + extra_alloc > allocated)
                      {
                        char *memory;

                        allocated = 2 * allocated;
                        if (length + 1 + extra_alloc > allocated)
                          abort ();
                        if (result == initial_result)
                          memory = (char *) malloc (allocated);
                        else
                          memory = (char *) realloc (result, allocated);
                        if (memory == NULL)
                          {
                            if (result != initial_result)
                              free (result);
                            errno = ENOMEM;
                            return -1;
                          }
                        if (result == initial_result)
                          memcpy (memory, initial_result, length);
                        result = memory;
                        grow = false;
                      }
                    /* The input is invalid in FROM_CODESET.  Eat up one byte
                       and emit a question mark.  */
                    if (!incremented)
                      {
                        if (insize == 0)
                          abort ();
                        inptr++;
                        insize--;
                      }
                    result[length] = '?';
                    length++;
                  }
                else
                  goto indirectly;
              }
            else
              {
                if (result != initial_result)
                  {
                    int saved_errno = errno;
                    free (result);
                    errno = saved_errno;
                  }
                return -1;
              }
          }
        if (insize == 0)
          break;
        if (grow)
          {
            char *memory;

            allocated = 2 * allocated;
            if (result == initial_result)
              memory = (char *) malloc (allocated);
            else
              memory = (char *) realloc (result, allocated);
            if (memory == NULL)
              {
                if (result != initial_result)
                  free (result);
                errno = ENOMEM;
                return -1;
              }
            if (result == initial_result)
              memcpy (memory, initial_result, length);
            result = memory;
          }
      }
  }

  /* Now get the conversion state back to the initial state.
     But avoid glibc-2.1 bug and Solaris 2.7 bug.  */
#if defined _LIBICONV_VERSION \
    || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
         || defined __sun)
  for (;;)
    {
      char *outptr = result + length;
      size_t outsize = allocated - extra_alloc - length;
      size_t res;

      res = iconv (cd, NULL, NULL, &outptr, &outsize);
      length = outptr - result;
      if (res == (size_t)(-1))
        {
          if (errno == E2BIG)
            {
              char *memory;

              allocated = 2 * allocated;
              if (result == initial_result)
                memory = (char *) malloc (allocated);
              else
                memory = (char *) realloc (result, allocated);
              if (memory == NULL)
                {
                  if (result != initial_result)
                    free (result);
                  errno = ENOMEM;
                  return -1;
                }
              if (result == initial_result)
                memcpy (memory, initial_result, length);
              result = memory;
            }
          else
            {
              if (result != initial_result)
                {
                  int saved_errno = errno;
                  free (result);
                  errno = saved_errno;
                }
              return -1;
            }
        }
      else
        break;
    }
#endif

  /* The direct conversion succeeded.  */
  goto done;

 indirectly:
  /* The direct conversion failed.
     Use a conversion through UTF-8.  */
  if (offsets != NULL)
    {
      size_t i;

      for (i = 0; i < srclen; i++)
        offsets[i] = (size_t)(-1);

      last_length = (size_t)(-1);
    }
  length = 0;
  {
    const bool slowly = (offsets != NULL || handler == iconveh_error);
# define utf8bufsize 4096 /* may also be smaller or larger than tmpbufsize */
    char utf8buf[utf8bufsize + 1];
    size_t utf8len = 0;
    const char *in1ptr = src;
    size_t in1size = srclen;
    bool do_final_flush1 = true;
    bool do_final_flush2 = true;

    /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug.  */
# if defined _LIBICONV_VERSION \
     || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
          || defined __sun)
    /* Set to the initial state.  */
    if (cd1 != (iconv_t)(-1))
      iconv (cd1, NULL, NULL, NULL, NULL);
    if (cd2 != (iconv_t)(-1))
      iconv (cd2, NULL, NULL, NULL, NULL);
# endif

    while (in1size > 0 || do_final_flush1 || utf8len > 0 || do_final_flush2)
      {
        char *out1ptr = utf8buf + utf8len;
        size_t out1size = utf8bufsize - utf8len;
        bool incremented1;
        size_t res1;
        int errno1;

        /* Conversion step 1: from FROM_CODESET to UTF-8.  */
        if (in1size > 0)
          {
            if (offsets != NULL
                && length != last_length) /* ensure that offset[] be increasing */
              {
                offsets[in1ptr - src] = length;
                last_length = length;
              }
            if (cd1 != (iconv_t)(-1))
              {
                if (slowly)
                  res1 = iconv_carefully_1 (cd1,
                                            &in1ptr, &in1size,
                                            &out1ptr, &out1size,
                                            &incremented1);
                else
                  res1 = iconv_carefully (cd1,
                                          &in1ptr, &in1size,
                                          &out1ptr, &out1size,
                                          &incremented1);
              }
            else
              {
                /* FROM_CODESET is UTF-8.  */
                res1 = utf8conv_carefully (slowly,
                                           &in1ptr, &in1size,
                                           &out1ptr, &out1size,
                                           &incremented1);
              }
          }
        else if (do_final_flush1)
          {
            /* Now get the conversion state of CD1 back to the initial state.
               But avoid glibc-2.1 bug and Solaris 2.7 bug.  */
# if defined _LIBICONV_VERSION \
     || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
          || defined __sun)
            if (cd1 != (iconv_t)(-1))
              res1 = iconv (cd1, NULL, NULL, &out1ptr, &out1size);
            else
# endif
              res1 = 0;
            do_final_flush1 = false;
            incremented1 = true;
          }
        else
          {
            res1 = 0;
            incremented1 = true;
          }
        if (res1 == (size_t)(-1)
            && !(errno == E2BIG || errno == EINVAL || errno == EILSEQ))
          {
            if (result != initial_result)
              {
                int saved_errno = errno;
                free (result);
                errno = saved_errno;
              }
            return -1;
          }
        if (res1 == (size_t)(-1)
            && errno == EILSEQ && handler != iconveh_error)
          {
            /* The input is invalid in FROM_CODESET.  Eat up one byte and
               emit a question mark.  Room for the question mark was allocated
               at the end of utf8buf.  */
            if (!incremented1)
              {
                if (in1size == 0)
                  abort ();
                in1ptr++;
                in1size--;
              }
            *out1ptr++ = '?';
            res1 = 0;
          }
        errno1 = errno;
        utf8len = out1ptr - utf8buf;

        if (offsets != NULL
            || in1size == 0
            || utf8len > utf8bufsize / 2
            || (res1 == (size_t)(-1) && errno1 == E2BIG))
          {
            /* Conversion step 2: from UTF-8 to TO_CODESET.  */
            const char *in2ptr = utf8buf;
            size_t in2size = utf8len;

            while (in2size > 0
                   || (in1size == 0 && !do_final_flush1 && do_final_flush2))
              {
                char *out2ptr = result + length;
                size_t out2size = allocated - extra_alloc - length;
                bool incremented2;
                size_t res2;
                bool grow;

                if (in2size > 0)
                  {
                    if (cd2 != (iconv_t)(-1))
                      res2 = iconv_carefully (cd2,
                                              &in2ptr, &in2size,
                                              &out2ptr, &out2size,
                                              &incremented2);
                    else
                      /* TO_CODESET is UTF-8.  */
                      res2 = utf8conv_carefully (false,
                                                 &in2ptr, &in2size,
                                                 &out2ptr, &out2size,
                                                 &incremented2);
                  }
                else /* in1size == 0 && !do_final_flush1
                        && in2size == 0 && do_final_flush2 */
                  {
                    /* Now get the conversion state of CD1 back to the initial
                       state.  But avoid glibc-2.1 bug and Solaris 2.7 bug.  */
# if defined _LIBICONV_VERSION \
     || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \
          || defined __sun)
                    if (cd2 != (iconv_t)(-1))
                      res2 = iconv (cd2, NULL, NULL, &out2ptr, &out2size);
                    else
# endif
                      res2 = 0;
                    do_final_flush2 = false;
                    incremented2 = true;
                  }

                length = out2ptr - result;
                grow = (length + extra_alloc > allocated / 2);
                if (res2 == (size_t)(-1))
                  {
                    if (errno == E2BIG)
                      grow = true;
                    else if (errno == EINVAL)
                      break;
                    else if (errno == EILSEQ && handler != iconveh_error)
                      {
                        /* Error handling can produce up to 10 bytes of ASCII
                           output.  But TO_CODESET may be UCS-2, UTF-16 or
                           UCS-4, so use CD2 here as well.  */
                        char scratchbuf[10];
                        size_t scratchlen;
                        ucs4_t uc;
                        const char *inptr;
                        size_t insize;
                        size_t res;

                        if (incremented2)
                          {
                            if (u8_prev (&uc, (const uint8_t *) in2ptr,
                                         (const uint8_t *) utf8buf)
                                == NULL)
                              abort ();
                          }
                        else
                          {
                            int n;
                            if (in2size == 0)
                              abort ();
                            n = u8_mbtouc_unsafe (&uc, (const uint8_t *) in2ptr,
                                                  in2size);
                            in2ptr += n;
                            in2size -= n;
                          }

                        if (handler == iconveh_escape_sequence)
                          {
                            static char hex[16] = "0123456789ABCDEF";
                            scratchlen = 0;
                            scratchbuf[scratchlen++] = '\\';
                            if (uc < 0x10000)
                              scratchbuf[scratchlen++] = 'u';
                            else
                              {
                                scratchbuf[scratchlen++] = 'U';
                                scratchbuf[scratchlen++] = hex[(uc>>28) & 15];
                                scratchbuf[scratchlen++] = hex[(uc>>24) & 15];
                                scratchbuf[scratchlen++] = hex[(uc>>20) & 15];
                                scratchbuf[scratchlen++] = hex[(uc>>16) & 15];
                              }
                            scratchbuf[scratchlen++] = hex[(uc>>12) & 15];
                            scratchbuf[scratchlen++] = hex[(uc>>8) & 15];
                            scratchbuf[scratchlen++] = hex[(uc>>4) & 15];
                            scratchbuf[scratchlen++] = hex[uc & 15];
                          }
                        else
                          {
                            scratchbuf[0] = '?';
                            scratchlen = 1;
                          }

                        inptr = scratchbuf;
                        insize = scratchlen;
                        if (cd2 != (iconv_t)(-1))
                          res = iconv (cd2,
                                       (ICONV_CONST char **) &inptr, &insize,
                                       &out2ptr, &out2size);
                        else
                          {
                            /* TO_CODESET is UTF-8.  */
                            if (out2size >= insize)
                              {
                                memcpy (out2ptr, inptr, insize);
                                out2ptr += insize;
                                out2size -= insize;
                                inptr += insize;
                                insize = 0;
                                res = 0;
                              }
                            else
                              {
                                errno = E2BIG;
                                res = (size_t)(-1);
                              }
                          }
                        length = out2ptr - result;
                        if (res == (size_t)(-1) && errno == E2BIG)
                          {
                            char *memory;

                            allocated = 2 * allocated;
                            if (length + 1 + extra_alloc > allocated)
                              abort ();
                            if (result == initial_result)
                              memory = (char *) malloc (allocated);
                            else
                              memory = (char *) realloc (result, allocated);
                            if (memory == NULL)
                              {
                                if (result != initial_result)
                                  free (result);
                                errno = ENOMEM;
                                return -1;
                              }
                            if (result == initial_result)
                              memcpy (memory, initial_result, length);
                            result = memory;
                            grow = false;

                            out2ptr = result + length;
                            out2size = allocated - extra_alloc - length;
                            if (cd2 != (iconv_t)(-1))
                              res = iconv (cd2,
                                           (ICONV_CONST char **) &inptr,
                                           &insize,
                                           &out2ptr, &out2size);
                            else
                              {
                                /* TO_CODESET is UTF-8.  */
                                if (!(out2size >= insize))
                                  abort ();
                                memcpy (out2ptr, inptr, insize);
                                out2ptr += insize;
                                out2size -= insize;
                                inptr += insize;
                                insize = 0;
                                res = 0;
                              }
                            length = out2ptr - result;
                          }
# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__)
                        /* Irix iconv() inserts a NUL byte if it cannot convert.
                           NetBSD iconv() inserts a question mark if it cannot
                           convert.
                           Only GNU libiconv and GNU libc are known to prefer
                           to fail rather than doing a lossy conversion.  */
                        if (res != (size_t)(-1) && res > 0)
                          {
                            errno = EILSEQ;
                            res = (size_t)(-1);
                          }
# endif
                        if (res == (size_t)(-1))
                          {
                            /* Failure converting the ASCII replacement.  */
                            if (result != initial_result)
                              {
                                int saved_errno = errno;
                                free (result);
                                errno = saved_errno;
                              }
                            return -1;
                          }
                      }
                    else
                      {
                        if (result != initial_result)
                          {
                            int saved_errno = errno;
                            free (result);
                            errno = saved_errno;
                          }
                        return -1;
                      }
                  }
                if (!(in2size > 0
                      || (in1size == 0 && !do_final_flush1 && do_final_flush2)))
                  break;
                if (grow)
                  {
                    char *memory;

                    allocated = 2 * allocated;
                    if (result == initial_result)
                      memory = (char *) malloc (allocated);
                    else
                      memory = (char *) realloc (result, allocated);
                    if (memory == NULL)
                      {
                        if (result != initial_result)
                          free (result);
                        errno = ENOMEM;
                        return -1;
                      }
                    if (result == initial_result)
                      memcpy (memory, initial_result, length);
                    result = memory;
                  }
              }

            /* Move the remaining bytes to the beginning of utf8buf.  */
            if (in2size > 0)
              memmove (utf8buf, in2ptr, in2size);
            utf8len = in2size;
          }

        if (res1 == (size_t)(-1))
          {
            if (errno1 == EINVAL)
              in1size = 0;
            else if (errno1 == EILSEQ)
              {
                if (result != initial_result)
                  free (result);
                errno = errno1;
                return -1;
              }
          }
      }
# undef utf8bufsize
  }

 done:
  /* Now the final memory allocation.  */
  if (result == tmpbuf)
    {
      size_t memsize = length + extra_alloc;

      if (*resultp != NULL && *lengthp >= memsize)
        result = *resultp;
      else
        {
          char *memory;

          memory = (char *) malloc (memsize > 0 ? memsize : 1);
          if (memory != NULL)
            result = memory;
          else
            {
              errno = ENOMEM;
              return -1;
            }
        }
      memcpy (result, tmpbuf, length);
    }
  else if (result != *resultp && length + extra_alloc < allocated)
    {
      /* Shrink the allocated memory if possible.  */
      size_t memsize = length + extra_alloc;
      char *memory;

      memory = (char *) realloc (result, memsize > 0 ? memsize : 1);
      if (memory != NULL)
        result = memory;
    }
  *resultp = result;
  *lengthp = length;
  return 0;
# undef tmpbuf
# undef tmpbufsize
}

int
mem_cd_iconveh (const char *src, size_t srclen,
                const iconveh_t *cd,
                enum iconv_ilseq_handler handler,
                size_t *offsets,
                char **resultp, size_t *lengthp)
{
  return mem_cd_iconveh_internal (src, srclen, cd->cd, cd->cd1, cd->cd2,
                                  handler, 0, offsets, resultp, lengthp);
}

char *
str_cd_iconveh (const char *src,
                const iconveh_t *cd,
                enum iconv_ilseq_handler handler)
{
  /* For most encodings, a trailing NUL byte in the input will be converted
     to a trailing NUL byte in the output.  But not for UTF-7.  So that this
     function is usable for UTF-7, we have to exclude the NUL byte from the
     conversion and add it by hand afterwards.  */
  char *result = NULL;
  size_t length = 0;
  int retval = mem_cd_iconveh_internal (src, strlen (src),
                                        cd->cd, cd->cd1, cd->cd2, handler, 1,
                                        NULL, &result, &length);

  if (retval < 0)
    {
      if (result != NULL)
        {
          int saved_errno = errno;
          free (result);
          errno = saved_errno;
        }
      return NULL;
    }

  /* Add the terminating NUL byte.  */
  result[length] = '\0';

  return result;
}

#endif

int
mem_iconveh (const char *src, size_t srclen,
             const char *from_codeset, const char *to_codeset,
             enum iconv_ilseq_handler handler,
             size_t *offsets,
             char **resultp, size_t *lengthp)
{
  if (srclen == 0)
    {
      /* Nothing to convert.  */
      *lengthp = 0;
      return 0;
    }
  else if (offsets == NULL && c_strcasecmp (from_codeset, to_codeset) == 0)
    {
      char *result;

      if (*resultp != NULL && *lengthp >= srclen)
        result = *resultp;
      else
        {
          result = (char *) malloc (srclen);
          if (result == NULL)
            {
              errno = ENOMEM;
              return -1;
            }
        }
      memcpy (result, src, srclen);
      *resultp = result;
      *lengthp = srclen;
      return 0;
    }
  else
    {
#if HAVE_ICONV
      iconveh_t cd;
      char *result;
      size_t length;
      int retval;

      if (iconveh_open (to_codeset, from_codeset, &cd) < 0)
        return -1;

      result = *resultp;
      length = *lengthp;
      retval = mem_cd_iconveh (src, srclen, &cd, handler, offsets,
                               &result, &length);

      if (retval < 0)
        {
          /* Close cd, but preserve the errno from str_cd_iconv.  */
          int saved_errno = errno;
          iconveh_close (&cd);
          errno = saved_errno;
        }
      else
        {
          if (iconveh_close (&cd) < 0)
            {
              /* Return -1, but free the allocated memory, and while doing
                 that, preserve the errno from iconveh_close.  */
              int saved_errno = errno;
              if (result != *resultp && result != NULL)
                free (result);
              errno = saved_errno;
              return -1;
            }
          *resultp = result;
          *lengthp = length;
        }
      return retval;
#else
      /* This is a different error code than if iconv_open existed but didn't
         support from_codeset and to_codeset, so that the caller can emit
         an error message such as
           "iconv() is not supported. Installing GNU libiconv and
            then reinstalling this package would fix this."  */
      errno = ENOSYS;
      return -1;
#endif
    }
}

char *
str_iconveh (const char *src,
             const char *from_codeset, const char *to_codeset,
             enum iconv_ilseq_handler handler)
{
  if (*src == '\0' || c_strcasecmp (from_codeset, to_codeset) == 0)
    {
      char *result = strdup (src);

      if (result == NULL)
        errno = ENOMEM;
      return result;
    }
  else
    {
#if HAVE_ICONV
      iconveh_t cd;
      char *result;

      if (iconveh_open (to_codeset, from_codeset, &cd) < 0)
        return NULL;

      result = str_cd_iconveh (src, &cd, handler);

      if (result == NULL)
        {
          /* Close cd, but preserve the errno from str_cd_iconv.  */
          int saved_errno = errno;
          iconveh_close (&cd);
          errno = saved_errno;
        }
      else
        {
          if (iconveh_close (&cd) < 0)
            {
              /* Return NULL, but free the allocated memory, and while doing
                 that, preserve the errno from iconveh_close.  */
              int saved_errno = errno;
              free (result);
              errno = saved_errno;
              return NULL;
            }
        }
      return result;
#else
      /* This is a different error code than if iconv_open existed but didn't
         support from_codeset and to_codeset, so that the caller can emit
         an error message such as
           "iconv() is not supported. Installing GNU libiconv and
            then reinstalling this package would fix this."  */
      errno = ENOSYS;
      return NULL;
#endif
    }
}