summaryrefslogtreecommitdiffstats
path: root/Bugzilla/Bug.pm
blob: f297ec6813dd523ed534ad22ca095461800875d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
# -*- Mode: perl; indent-tabs-mode: nil -*-
#
# The contents of this file are subject to the Mozilla Public
# License Version 1.1 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy of
# the License at http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS
# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
# implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code is the Bugzilla Bug Tracking System.
#
# The Initial Developer of the Original Code is Netscape Communications
# Corporation. Portions created by Netscape are
# Copyright (C) 1998 Netscape Communications Corporation. All
# Rights Reserved.
#
# Contributor(s): Dawn Endico    <endico@mozilla.org>
#                 Terry Weissman <terry@mozilla.org>
#                 Chris Yeh      <cyeh@bluemartini.com>
#                 Bradley Baetz  <bbaetz@acm.org>
#                 Dave Miller    <justdave@bugzilla.org>
#                 Max Kanat-Alexander <mkanat@bugzilla.org>
#                 Frédéric Buclin <LpSolit@gmail.com>
#                 Lance Larsh <lance.larsh@oracle.com>

package Bugzilla::Bug;

use strict;

use vars qw($legal_keywords @legal_platform
            @legal_priority @legal_severity @legal_opsys @legal_bug_status
            @settable_resolution %components %target_milestone
            @enterable_products %milestoneurl %prodmaxvotes);

use CGI::Carp qw(fatalsToBrowser);

use Bugzilla::Attachment;
use Bugzilla::Config;
use Bugzilla::Constants;
use Bugzilla::Field;
use Bugzilla::Flag;
use Bugzilla::FlagType;
use Bugzilla::User;
use Bugzilla::Util;
use Bugzilla::Error;
use Bugzilla::Product;

use base qw(Exporter);
@Bugzilla::Bug::EXPORT = qw(
    AppendComment ValidateComment
    bug_alias_to_id ValidateBugAlias ValidateBugID
    RemoveVotes CheckIfVotedConfirmed
    LogActivityEntry
);

#####################################################################
# Constants
#####################################################################

# Used in LogActivityEntry(). Gives the max length of lines in the
# activity table.
use constant MAX_LINE_LENGTH => 254;

# Used in ValidateComment(). Gives the max length allowed for a comment.
use constant MAX_COMMENT_LENGTH => 65535;

#####################################################################

# create a new empty bug
#
sub new {
  my $type = shift();
  my %bug;

  # create a ref to an empty hash and bless it
  #
  my $self = {%bug};
  bless $self, $type;

  # construct from a hash containing a bug's info
  #
  if ($#_ == 1) {
    $self->initBug(@_);
  } else {
    confess("invalid number of arguments \($#_\)($_)");
  }

  # bless as a Bug
  #
  return $self;
}

# dump info about bug into hash unless user doesn't have permission
# user_id 0 is used when person is not logged in.
#
sub initBug  {
  my $self = shift();
  my ($bug_id, $user_id) = (@_);
  my $dbh = Bugzilla->dbh;

  $bug_id = trim($bug_id);

  my $old_bug_id = $bug_id;

  # If the bug ID isn't numeric, it might be an alias, so try to convert it.
  $bug_id = bug_alias_to_id($bug_id) if $bug_id !~ /^0*[1-9][0-9]*$/;

  if ((! defined $bug_id) || (!$bug_id) || (!detaint_natural($bug_id))) {
      # no bug number given or the alias didn't match a bug
      $self->{'bug_id'} = $old_bug_id;
      $self->{'error'} = "InvalidBugId";
      return $self;
  }

  # If the user is not logged in, sets $user_id to 0.
  # Else gets $user_id from the user login name if this
  # argument is not numeric.
  my $stored_user_id = $user_id;
  if (!defined $user_id) {
    $user_id = 0;
  } elsif (!detaint_natural($user_id)) {
    $user_id = login_to_id($stored_user_id); 
  }

  $self->{'who'} = new Bugzilla::User($user_id);

    my $custom_fields = "";
    if (scalar(Bugzilla->custom_field_names) > 0) {
        $custom_fields = ", " . join(", ", Bugzilla->custom_field_names);
    }

  my $query = "
    SELECT
      bugs.bug_id, alias, products.classification_id, classifications.name,
      bugs.product_id, products.name, version,
      rep_platform, op_sys, bug_status, resolution, priority,
      bug_severity, bugs.component_id, components.name, 
      assigned_to AS assigned_to_id, reporter AS reporter_id,
      bug_file_loc, short_desc, target_milestone,
      qa_contact AS qa_contact_id, status_whiteboard, " .
      $dbh->sql_date_format('creation_ts', '%Y.%m.%d %H:%i') . ",
      delta_ts, COALESCE(SUM(votes.vote_count), 0), everconfirmed,
      reporter_accessible, cclist_accessible,
      estimated_time, remaining_time, " .
      $dbh->sql_date_format('deadline', '%Y-%m-%d') .
      $custom_fields . "
    FROM bugs
       LEFT JOIN votes
              ON bugs.bug_id = votes.bug_id
      INNER JOIN components
              ON components.id = bugs.component_id
      INNER JOIN products
              ON products.id = bugs.product_id
      INNER JOIN classifications
              ON classifications.id = products.classification_id
      WHERE bugs.bug_id = ? " .
    $dbh->sql_group_by('bugs.bug_id', 'alias, products.classification_id,
      classifications.name, bugs.product_id, products.name, version,
      rep_platform, op_sys, bug_status, resolution, priority,
      bug_severity, bugs.component_id, components.name, assigned_to,
      reporter, bug_file_loc, short_desc, target_milestone,
      qa_contact, status_whiteboard, everconfirmed, creation_ts, 
      delta_ts, reporter_accessible, cclist_accessible,
      estimated_time, remaining_time, deadline');

  my $bug_sth = $dbh->prepare($query);
  $bug_sth->execute($bug_id);
  my @row;

  if ((@row = $bug_sth->fetchrow_array()) 
      && $self->{'who'}->can_see_bug($bug_id)) {
    my $count = 0;
    my %fields;
    foreach my $field ("bug_id", "alias", "classification_id", "classification",
                       "product_id", "product", "version", 
                       "rep_platform", "op_sys", "bug_status", "resolution", 
                       "priority", "bug_severity", "component_id", "component",
                       "assigned_to_id", "reporter_id", 
                       "bug_file_loc", "short_desc",
                       "target_milestone", "qa_contact_id", "status_whiteboard",
                       "creation_ts", "delta_ts", "votes", "everconfirmed",
                       "reporter_accessible", "cclist_accessible",
                       "estimated_time", "remaining_time", "deadline",
                       Bugzilla->custom_field_names)
      {
        $fields{$field} = shift @row;
        if (defined $fields{$field}) {
            $self->{$field} = $fields{$field};
        }
        $count++;
    }
  } elsif (@row) {
      $self->{'bug_id'} = $bug_id;
      $self->{'error'} = "NotPermitted";
      return $self;
  } else {
      $self->{'bug_id'} = $bug_id;
      $self->{'error'} = "NotFound";
      return $self;
  }

  $self->{'isunconfirmed'} = ($self->{bug_status} eq 'UNCONFIRMED');
  $self->{'isopened'} = &::IsOpenedState($self->{bug_status});
  
  return $self;
}

# This is the correct way to delete bugs from the DB.
# No bug should be deleted from anywhere else except from here.
#
sub remove_from_db {
    my ($self) = @_;
    my $dbh = Bugzilla->dbh;

    if ($self->{'error'}) {
        ThrowCodeError("bug_error", { bug => $self });
    }

    my $bug_id = $self->{'bug_id'};

    # tables having 'bugs.bug_id' as a foreign key:
    # - attachments
    # - bug_group_map
    # - bugs
    # - bugs_activity
    # - cc
    # - dependencies
    # - duplicates
    # - flags
    # - keywords
    # - longdescs
    # - votes

    $dbh->bz_lock_tables('attachments WRITE', 'bug_group_map WRITE',
                         'bugs WRITE', 'bugs_activity WRITE', 'cc WRITE',
                         'dependencies WRITE', 'duplicates WRITE',
                         'flags WRITE', 'keywords WRITE',
                         'longdescs WRITE', 'votes WRITE');

    $dbh->do("DELETE FROM bug_group_map WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM bugs_activity WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM cc WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM dependencies WHERE blocked = ? OR dependson = ?",
             undef, ($bug_id, $bug_id));
    $dbh->do("DELETE FROM duplicates WHERE dupe = ? OR dupe_of = ?",
             undef, ($bug_id, $bug_id));
    $dbh->do("DELETE FROM flags WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM keywords WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM longdescs WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM votes WHERE bug_id = ?", undef, $bug_id);
    # Several of the previous tables also depend on attach_id.
    $dbh->do("DELETE FROM attachments WHERE bug_id = ?", undef, $bug_id);
    $dbh->do("DELETE FROM bugs WHERE bug_id = ?", undef, $bug_id);

    $dbh->bz_unlock_tables();

    # Now this bug no longer exists
    $self->DESTROY;
    return $self;
}


#####################################################################
# Class Accessors
#####################################################################

sub fields {
    my $class = shift;

    return (
        # Standard Fields
        # Keep this ordering in sync with bugzilla.dtd.
        qw(bug_id alias creation_ts short_desc delta_ts
           reporter_accessible cclist_accessible
           classification_id classification
           product component version rep_platform op_sys
           bug_status resolution
           bug_file_loc status_whiteboard keywords
           priority bug_severity target_milestone
           dependson blocked votes
           reporter assigned_to cc),
    
        # Conditional Fields
        Param('useqacontact') ? "qa_contact" : (),
        Param('timetrackinggroup') ? qw(estimated_time remaining_time
                                        actual_time deadline)
                                   : (),
    
        # Custom Fields
        Bugzilla->custom_field_names
    );
}


#####################################################################
# Instance Accessors
#####################################################################

# These subs are in alphabetical order, as much as possible.
# If you add a new sub, please try to keep it in alphabetical order
# with the other ones.

# Note: If you add a new method, remember that you must check the error
# state of the bug before returning any data. If $self->{error} is
# defined, then return something empty. Otherwise you risk potential
# security holes.

sub dup_id {
    my ($self) = @_;
    return $self->{'dup_id'} if exists $self->{'dup_id'};

    $self->{'dup_id'} = undef;
    return if $self->{'error'};

    if ($self->{'resolution'} eq 'DUPLICATE') { 
        my $dbh = Bugzilla->dbh;
        $self->{'dup_id'} =
          $dbh->selectrow_array(q{SELECT dupe_of 
                                  FROM duplicates
                                  WHERE dupe = ?},
                                undef,
                                $self->{'bug_id'});
    }
    return $self->{'dup_id'};
}

sub actual_time {
    my ($self) = @_;
    return $self->{'actual_time'} if exists $self->{'actual_time'};

    if ( $self->{'error'} || 
         !Bugzilla->user->in_group(Param("timetrackinggroup")) ) {
        $self->{'actual_time'} = undef;
        return $self->{'actual_time'};
    }

    my $sth = Bugzilla->dbh->prepare("SELECT SUM(work_time)
                                      FROM longdescs 
                                      WHERE longdescs.bug_id=?");
    $sth->execute($self->{bug_id});
    $self->{'actual_time'} = $sth->fetchrow_array();
    return $self->{'actual_time'};
}

sub any_flags_requesteeble {
    my ($self) = @_;
    return $self->{'any_flags_requesteeble'} 
        if exists $self->{'any_flags_requesteeble'};
    return 0 if $self->{'error'};

    $self->{'any_flags_requesteeble'} = 
        grep($_->{'is_requesteeble'}, @{$self->flag_types});

    return $self->{'any_flags_requesteeble'};
}

sub attachments {
    my ($self) = @_;
    return $self->{'attachments'} if exists $self->{'attachments'};
    return [] if $self->{'error'};

    $self->{'attachments'} =
        Bugzilla::Attachment->get_attachments_by_bug($self->bug_id);
    return $self->{'attachments'};
}

sub assigned_to {
    my ($self) = @_;
    return $self->{'assigned_to'} if exists $self->{'assigned_to'};
    $self->{'assigned_to_id'} = 0 if $self->{'error'};
    $self->{'assigned_to'} = new Bugzilla::User($self->{'assigned_to_id'});
    return $self->{'assigned_to'};
}

sub blocked {
    my ($self) = @_;
    return $self->{'blocked'} if exists $self->{'blocked'};
    return [] if $self->{'error'};
    $self->{'blocked'} = EmitDependList("dependson", "blocked", $self->bug_id);
    return $self->{'blocked'};
}

# Even bugs in an error state always have a bug_id.
sub bug_id { $_[0]->{'bug_id'}; }

sub cc {
    my ($self) = @_;
    return $self->{'cc'} if exists $self->{'cc'};
    return [] if $self->{'error'};

    my $dbh = Bugzilla->dbh;
    $self->{'cc'} = $dbh->selectcol_arrayref(
        q{SELECT profiles.login_name FROM cc, profiles
           WHERE bug_id = ?
             AND cc.who = profiles.userid
        ORDER BY profiles.login_name},
      undef, $self->bug_id);

    $self->{'cc'} = undef if !scalar(@{$self->{'cc'}});

    return $self->{'cc'};
}

sub dependson {
    my ($self) = @_;
    return $self->{'dependson'} if exists $self->{'dependson'};
    return [] if $self->{'error'};
    $self->{'dependson'} = 
        EmitDependList("blocked", "dependson", $self->bug_id);
    return $self->{'dependson'};
}

sub flag_types {
    my ($self) = @_;
    return $self->{'flag_types'} if exists $self->{'flag_types'};
    return [] if $self->{'error'};

    # The types of flags that can be set on this bug.
    # If none, no UI for setting flags will be displayed.
    my $flag_types = Bugzilla::FlagType::match(
        {'target_type'  => 'bug',
         'product_id'   => $self->{'product_id'}, 
         'component_id' => $self->{'component_id'} });

    foreach my $flag_type (@$flag_types) {
        $flag_type->{'flags'} = Bugzilla::Flag::match(
            { 'bug_id'      => $self->bug_id,
              'type_id'     => $flag_type->{'id'},
              'target_type' => 'bug',
              'is_active'   => 1 });
    }

    $self->{'flag_types'} = $flag_types;

    return $self->{'flag_types'};
}

sub keywords {
    my ($self) = @_;
    return $self->{'keywords'} if exists $self->{'keywords'};
    return () if $self->{'error'};

    my $dbh = Bugzilla->dbh;
    my $list_ref = $dbh->selectcol_arrayref(
         "SELECT keyworddefs.name
            FROM keyworddefs, keywords
           WHERE keywords.bug_id = ?
             AND keyworddefs.id = keywords.keywordid
        ORDER BY keyworddefs.name",
        undef, ($self->bug_id));

    $self->{'keywords'} = join(', ', @$list_ref);
    return $self->{'keywords'};
}

sub longdescs {
    my ($self) = @_;
    return $self->{'longdescs'} if exists $self->{'longdescs'};
    return [] if $self->{'error'};
    $self->{'longdescs'} = GetComments($self->{bug_id});
    return $self->{'longdescs'};
}

sub milestoneurl {
    my ($self) = @_;
    return $self->{'milestoneurl'} if exists $self->{'milestoneurl'};
    return '' if $self->{'error'};
    $self->{'milestoneurl'} = $::milestoneurl{$self->{product}};
    return $self->{'milestoneurl'};
}

sub qa_contact {
    my ($self) = @_;
    return $self->{'qa_contact'} if exists $self->{'qa_contact'};
    return undef if $self->{'error'};

    if (Param('useqacontact') && $self->{'qa_contact_id'}) {
        $self->{'qa_contact'} = new Bugzilla::User($self->{'qa_contact_id'});
    } else {
        # XXX - This is somewhat inconsistent with the assignee/reporter 
        # methods, which will return an empty User if they get a 0. 
        # However, we're keeping it this way now, for backwards-compatibility.
        $self->{'qa_contact'} = undef;
    }
    return $self->{'qa_contact'};
}

sub reporter {
    my ($self) = @_;
    return $self->{'reporter'} if exists $self->{'reporter'};
    $self->{'reporter_id'} = 0 if $self->{'error'};
    $self->{'reporter'} = new Bugzilla::User($self->{'reporter_id'});
    return $self->{'reporter'};
}


sub show_attachment_flags {
    my ($self) = @_;
    return $self->{'show_attachment_flags'} 
        if exists $self->{'show_attachment_flags'};
    return 0 if $self->{'error'};

    # The number of types of flags that can be set on attachments to this bug
    # and the number of flags on those attachments.  One of these counts must be
    # greater than zero in order for the "flags" column to appear in the table
    # of attachments.
    my $num_attachment_flag_types = Bugzilla::FlagType::count(
        { 'target_type'  => 'attachment',
          'product_id'   => $self->{'product_id'},
          'component_id' => $self->{'component_id'} });
    my $num_attachment_flags = Bugzilla::Flag::count(
        { 'target_type'  => 'attachment',
          'bug_id'       => $self->bug_id,
          'is_active'    => 1 });

    $self->{'show_attachment_flags'} =
        ($num_attachment_flag_types || $num_attachment_flags);

    return $self->{'show_attachment_flags'};
}


sub use_keywords {
    return @::legal_keywords;
}

sub use_votes {
    my ($self) = @_;
    return 0 if $self->{'error'};

    return Param('usevotes')
      && $::prodmaxvotes{$self->{product}} > 0;
}

sub groups {
    my $self = shift;
    return $self->{'groups'} if exists $self->{'groups'};
    return [] if $self->{'error'};

    my $dbh = Bugzilla->dbh;
    my @groups;

    # Some of this stuff needs to go into Bugzilla::User

    # For every group, we need to know if there is ANY bug_group_map
    # record putting the current bug in that group and if there is ANY
    # user_group_map record putting the user in that group.
    # The LEFT JOINs are checking for record existence.
    #
    my $grouplist = Bugzilla->user->groups_as_string;
    my $sth = $dbh->prepare(
             "SELECT DISTINCT groups.id, name, description," .
             " CASE WHEN bug_group_map.group_id IS NOT NULL" .
             " THEN 1 ELSE 0 END," .
             " CASE WHEN groups.id IN($grouplist) THEN 1 ELSE 0 END," .
             " isactive, membercontrol, othercontrol" .
             " FROM groups" . 
             " LEFT JOIN bug_group_map" .
             " ON bug_group_map.group_id = groups.id" .
             " AND bug_id = ?" .
             " LEFT JOIN group_control_map" .
             " ON group_control_map.group_id = groups.id" .
             " AND group_control_map.product_id = ? " .
             " WHERE isbuggroup = 1" .
             " ORDER BY description");
    $sth->execute($self->{'bug_id'},
                  $self->{'product_id'});

    while (my ($groupid, $name, $description, $ison, $ingroup, $isactive,
            $membercontrol, $othercontrol) = $sth->fetchrow_array()) {

        $membercontrol ||= 0;

        # For product groups, we only want to use the group if either
        # (1) The bit is set and not required, or
        # (2) The group is Shown or Default for members and
        #     the user is a member of the group.
        if ($ison ||
            ($isactive && $ingroup
                       && (($membercontrol == CONTROLMAPDEFAULT)
                           || ($membercontrol == CONTROLMAPSHOWN))
            ))
        {
            my $ismandatory = $isactive
              && ($membercontrol == CONTROLMAPMANDATORY);

            push (@groups, { "bit" => $groupid,
                             "name" => $name,
                             "ison" => $ison,
                             "ingroup" => $ingroup,
                             "mandatory" => $ismandatory,
                             "description" => $description });
        }
    }

    $self->{'groups'} = \@groups;

    return $self->{'groups'};
}

sub user {
    my $self = shift;
    return $self->{'user'} if exists $self->{'user'};
    return {} if $self->{'error'};

    my $user = Bugzilla->user;
    my $canmove = Param('move-enabled') && $user->is_mover;

    # In the below, if the person hasn't logged in, then we treat them
    # as if they can do anything.  That's because we don't know why they
    # haven't logged in; it may just be because they don't use cookies.
    # Display everything as if they have all the permissions in the
    # world; their permissions will get checked when they log in and
    # actually try to make the change.
    my $unknown_privileges = !$user->id
                             || $user->in_group("editbugs");
    my $canedit = $unknown_privileges
                  || $user->id == $self->{assigned_to_id}
                  || (Param('useqacontact')
                      && $self->{'qa_contact_id'}
                      && $user->id == $self->{qa_contact_id});
    my $canconfirm = $unknown_privileges
                     || $user->in_group("canconfirm");
    my $isreporter = $user->id
                     && $user->id == $self->{reporter_id};

    $self->{'user'} = {canmove    => $canmove,
                       canconfirm => $canconfirm,
                       canedit    => $canedit,
                       isreporter => $isreporter};
    return $self->{'user'};
}

sub choices {
    my $self = shift;
    return $self->{'choices'} if exists $self->{'choices'};
    return {} if $self->{'error'};

    &::GetVersionTable();

    $self->{'choices'} = {};
    $self->{prod_obj} ||= new Bugzilla::Product({name => $self->{product}});

    # Fiddle the product list.
    my $seen_curr_prod;
    my @prodlist;

    foreach my $product (@::enterable_products) {
        if ($product eq $self->{'product'}) {
            # if it's the product the bug is already in, it's ALWAYS in
            # the popup, period, whether the user can see it or not, and
            # regardless of the disallownew setting.
            $seen_curr_prod = 1;
            push(@prodlist, $product);
            next;
        }

        if (!Bugzilla->user->can_enter_product($product)) {
            # If we're using bug groups to restrict entry on products, and
            # this product has an entry group, and the user is not in that
            # group, we don't want to include that product in this list.
            next;
        }

        push(@prodlist, $product);
    }

    # The current product is part of the popup, even if new bugs are no longer
    # allowed for that product
    if (!$seen_curr_prod) {
        push (@prodlist, $self->{'product'});
        @prodlist = sort @prodlist;
    }

    # Hack - this array contains "". See bug 106589.
    my @res = grep ($_, @::settable_resolution);

    $self->{'choices'} =
      {
       'product' => \@prodlist,
       'rep_platform' => \@::legal_platform,
       'priority' => \@::legal_priority,
       'bug_severity' => \@::legal_severity,
       'op_sys' => \@::legal_opsys,
       'bug_status' => \@::legal_bug_status,
       'resolution' => \@res,
       'component' => $::components{$self->{product}},
       'version' => [map($_->name, @{$self->{prod_obj}->versions})],
       'target_milestone' => $::target_milestone{$self->{product}},
      };

    return $self->{'choices'};
}

# Convenience Function. If you need speed, use this. If you need
# other Bug fields in addition to this, just create a new Bug with
# the alias.
# Queries the database for the bug with a given alias, and returns
# the ID of the bug if it exists or the undefined value if it doesn't.
sub bug_alias_to_id {
    my ($alias) = @_;
    return undef unless Param("usebugaliases");
    my $dbh = Bugzilla->dbh;
    trick_taint($alias);
    return $dbh->selectrow_array(
        "SELECT bug_id FROM bugs WHERE alias = ?", undef, $alias);
}

#####################################################################
# Subroutines
#####################################################################

sub AppendComment {
    my ($bugid, $whoid, $comment, $isprivate, $timestamp, $work_time) = @_;
    $work_time ||= 0;
    my $dbh = Bugzilla->dbh;

    ValidateTime($work_time, "work_time") if $work_time;
    trick_taint($work_time);

    # Use the date/time we were given if possible (allowing calling code
    # to synchronize the comment's timestamp with those of other records).
    $timestamp ||= $dbh->selectrow_array('SELECT NOW()');

    $comment =~ s/\r\n/\n/g;     # Handle Windows-style line endings.
    $comment =~ s/\r/\n/g;       # Handle Mac-style line endings.

    if ($comment =~ /^\s*$/) {  # Nothin' but whitespace
        return;
    }

    # Comments are always safe, because we always display their raw contents,
    # and we use them in a placeholder below.
    trick_taint($comment); 
    my $privacyval = $isprivate ? 1 : 0 ;
    $dbh->do(q{INSERT INTO longdescs
                      (bug_id, who, bug_when, thetext, isprivate, work_time)
               VALUES (?,?,?,?,?,?)}, undef,
             ($bugid, $whoid, $timestamp, $comment, $privacyval, $work_time));
    $dbh->do("UPDATE bugs SET delta_ts = ? WHERE bug_id = ?",
             undef, $timestamp, $bugid);
}
# This method is private and is not to be used outside of the Bug class.
sub EmitDependList {
    my ($myfield, $targetfield, $bug_id) = (@_);
    my $dbh = Bugzilla->dbh;
    my $list_ref =
        $dbh->selectcol_arrayref(
          "SELECT dependencies.$targetfield
             FROM dependencies, bugs
            WHERE dependencies.$myfield = ?
              AND bugs.bug_id = dependencies.$targetfield
         ORDER BY dependencies.$targetfield",
         undef, ($bug_id));
    return $list_ref;
}

sub ValidateTime {
    my ($time, $field) = @_;

    # regexp verifies one or more digits, optionally followed by a period and
    # zero or more digits, OR we have a period followed by one or more digits
    # (allow negatives, though, so people can back out errors in time reporting)
    if ($time !~ /^-?(?:\d+(?:\.\d*)?|\.\d+)$/) {
        ThrowUserError("number_not_numeric",
                       {field => "$field", num => "$time"});
    }

    # Only the "work_time" field is allowed to contain a negative value.
    if ( ($time < 0) && ($field ne "work_time") ) {
        ThrowUserError("number_too_small",
                       {field => "$field", num => "$time", min_num => "0"});
    }

    if ($time > 99999.99) {
        ThrowUserError("number_too_large",
                       {field => "$field", num => "$time", max_num => "99999.99"});
    }
}

sub GetComments {
    my ($id, $comment_sort_order) = (@_);
    $comment_sort_order = $comment_sort_order ||
        Bugzilla->user->settings->{'comment_sort_order'}->{'value'};

    my $sort_order = ($comment_sort_order eq "oldest_to_newest") ? 'asc' : 'desc';
    my $dbh = Bugzilla->dbh;
    my @comments;
    my $sth = $dbh->prepare(
            "SELECT  profiles.realname AS name, profiles.login_name AS email,
            " . $dbh->sql_date_format('longdescs.bug_when', '%Y.%m.%d %H:%i:%s') . "
               AS time, longdescs.thetext AS body, longdescs.work_time,
                     isprivate, already_wrapped
             FROM    longdescs, profiles
            WHERE    profiles.userid = longdescs.who
              AND    longdescs.bug_id = ?
            ORDER BY longdescs.bug_when $sort_order");
    $sth->execute($id);

    while (my $comment_ref = $sth->fetchrow_hashref()) {
        my %comment = %$comment_ref;

        $comment{'email'} .= Param('emailsuffix');
        $comment{'name'} = $comment{'name'} || $comment{'email'};

        push (@comments, \%comment);
    }
   
    if ($comment_sort_order eq "newest_to_oldest_desc_first") {
        unshift(@comments, pop @comments);
    }

    return \@comments;
}

# Get the activity of a bug, starting from $starttime (if given).
# This routine assumes ValidateBugID has been previously called.
sub GetBugActivity {
    my ($id, $starttime) = @_;
    my $dbh = Bugzilla->dbh;

    # Arguments passed to the SQL query.
    my @args = ($id);

    # Only consider changes since $starttime, if given.
    my $datepart = "";
    if (defined $starttime) {
        trick_taint($starttime);
        push (@args, $starttime);
        $datepart = "AND bugs_activity.bug_when > ?";
    }

    # Only includes attachments the user is allowed to see.
    my $suppjoins = "";
    my $suppwhere = "";
    if (Param("insidergroup") && !UserInGroup(Param('insidergroup'))) {
        $suppjoins = "LEFT JOIN attachments 
                   ON attachments.attach_id = bugs_activity.attach_id";
        $suppwhere = "AND COALESCE(attachments.isprivate, 0) = 0";
    }

    my $query = "
        SELECT COALESCE(fielddefs.description, " 
               # This is a hack - PostgreSQL requires both COALESCE
               # arguments to be of the same type, and this is the only
               # way supported by both MySQL 3 and PostgreSQL to convert
               # an integer to a string. MySQL 4 supports CAST.
               . $dbh->sql_string_concat('bugs_activity.fieldid', q{''}) .
               "), fielddefs.name, bugs_activity.attach_id, " .
        $dbh->sql_date_format('bugs_activity.bug_when', '%Y.%m.%d %H:%i:%s') .
            ", bugs_activity.removed, bugs_activity.added, profiles.login_name
          FROM bugs_activity
               $suppjoins
     LEFT JOIN fielddefs
            ON bugs_activity.fieldid = fielddefs.fieldid
    INNER JOIN profiles
            ON profiles.userid = bugs_activity.who
         WHERE bugs_activity.bug_id = ?
               $datepart
               $suppwhere
      ORDER BY bugs_activity.bug_when";

    my $list = $dbh->selectall_arrayref($query, undef, @args);

    my @operations;
    my $operation = {};
    my $changes = [];
    my $incomplete_data = 0;

    foreach my $entry (@$list) {
        my ($field, $fieldname, $attachid, $when, $removed, $added, $who) = @$entry;
        my %change;
        my $activity_visible = 1;

        # check if the user should see this field's activity
        if ($fieldname eq 'remaining_time'
            || $fieldname eq 'estimated_time'
            || $fieldname eq 'work_time'
            || $fieldname eq 'deadline')
        {
            $activity_visible = UserInGroup(Param('timetrackinggroup')) ? 1 : 0;
        } else {
            $activity_visible = 1;
        }

        if ($activity_visible) {
            # This gets replaced with a hyperlink in the template.
            $field =~ s/^Attachment// if $attachid;

            # Check for the results of an old Bugzilla data corruption bug
            $incomplete_data = 1 if ($added =~ /^\?/ || $removed =~ /^\?/);

            # An operation, done by 'who' at time 'when', has a number of
            # 'changes' associated with it.
            # If this is the start of a new operation, store the data from the
            # previous one, and set up the new one.
            if ($operation->{'who'}
                && ($who ne $operation->{'who'}
                    || $when ne $operation->{'when'}))
            {
                $operation->{'changes'} = $changes;
                push (@operations, $operation);

                # Create new empty anonymous data structures.
                $operation = {};
                $changes = [];
            }

            $operation->{'who'} = $who;
            $operation->{'when'} = $when;

            $change{'field'} = $field;
            $change{'fieldname'} = $fieldname;
            $change{'attachid'} = $attachid;
            $change{'removed'} = $removed;
            $change{'added'} = $added;
            push (@$changes, \%change);
        }
    }

    if ($operation->{'who'}) {
        $operation->{'changes'} = $changes;
        push (@operations, $operation);
    }

    return(\@operations, $incomplete_data);
}

# Update the bugs_activity table to reflect changes made in bugs.
sub LogActivityEntry {
    my ($i, $col, $removed, $added, $whoid, $timestamp) = @_;
    my $dbh = Bugzilla->dbh;
    # in the case of CCs, deps, and keywords, there's a possibility that someone
    # might try to add or remove a lot of them at once, which might take more
    # space than the activity table allows.  We'll solve this by splitting it
    # into multiple entries if it's too long.
    while ($removed || $added) {
        my ($removestr, $addstr) = ($removed, $added);
        if (length($removestr) > MAX_LINE_LENGTH) {
            my $commaposition = find_wrap_point($removed, MAX_LINE_LENGTH);
            $removestr = substr($removed, 0, $commaposition);
            $removed = substr($removed, $commaposition);
            $removed =~ s/^[,\s]+//; # remove any comma or space
        } else {
            $removed = ""; # no more entries
        }
        if (length($addstr) > MAX_LINE_LENGTH) {
            my $commaposition = find_wrap_point($added, MAX_LINE_LENGTH);
            $addstr = substr($added, 0, $commaposition);
            $added = substr($added, $commaposition);
            $added =~ s/^[,\s]+//; # remove any comma or space
        } else {
            $added = ""; # no more entries
        }
        trick_taint($addstr);
        trick_taint($removestr);
        my $fieldid = get_field_id($col);
        $dbh->do("INSERT INTO bugs_activity
                  (bug_id, who, bug_when, fieldid, removed, added)
                  VALUES (?, ?, ?, ?, ?, ?)",
                  undef, ($i, $whoid, $timestamp, $fieldid, $removestr, $addstr));
    }
}

# CountOpenDependencies counts the number of open dependent bugs for a
# list of bugs and returns a list of bug_id's and their dependency count
# It takes one parameter:
#  - A list of bug numbers whose dependencies are to be checked
sub CountOpenDependencies {
    my (@bug_list) = @_;
    my @dependencies;
    my $dbh = Bugzilla->dbh;

    my $sth = $dbh->prepare(
          "SELECT blocked, COUNT(bug_status) " .
            "FROM bugs, dependencies " .
           "WHERE blocked IN (" . (join "," , @bug_list) . ") " .
             "AND bug_id = dependson " .
             "AND bug_status IN ('" . (join "','", &::OpenStates())  . "') " .
          $dbh->sql_group_by('blocked'));
    $sth->execute();

    while (my ($bug_id, $dependencies) = $sth->fetchrow_array()) {
        push(@dependencies, { bug_id       => $bug_id,
                              dependencies => $dependencies });
    }

    return @dependencies;
}

sub ValidateComment {
    my ($comment) = @_;

    if (defined($comment) && length($comment) > MAX_COMMENT_LENGTH) {
        ThrowUserError("comment_too_long");
    }
}

# If a bug is moved to a product which allows less votes per bug
# compared to the previous product, extra votes need to be removed.
sub RemoveVotes {
    my ($id, $who, $reason) = (@_);
    my $dbh = Bugzilla->dbh;

    my $whopart = ($who) ? " AND votes.who = $who" : "";

    my $sth = $dbh->prepare("SELECT profiles.login_name, " .
                            "profiles.userid, votes.vote_count, " .
                            "products.votesperuser, products.maxvotesperbug " .
                            "FROM profiles " . 
                            "LEFT JOIN votes ON profiles.userid = votes.who " .
                            "LEFT JOIN bugs ON votes.bug_id = bugs.bug_id " .
                            "LEFT JOIN products ON products.id = bugs.product_id " .
                            "WHERE votes.bug_id = ? " . $whopart);
    $sth->execute($id);
    my @list;
    while (my ($name, $userid, $oldvotes, $votesperuser, $maxvotesperbug) = $sth->fetchrow_array()) {
        push(@list, [$name, $userid, $oldvotes, $votesperuser, $maxvotesperbug]);
    }

    # @messages stores all emails which have to be sent, if any.
    # This array is passed to the caller which will send these emails itself.
    my @messages = ();

    if (scalar(@list)) {
        foreach my $ref (@list) {
            my ($name, $userid, $oldvotes, $votesperuser, $maxvotesperbug) = (@$ref);
            my $s;

            $maxvotesperbug = min($votesperuser, $maxvotesperbug);

            # If this product allows voting and the user's votes are in
            # the acceptable range, then don't do anything.
            next if $votesperuser && $oldvotes <= $maxvotesperbug;

            # If the user has more votes on this bug than this product
            # allows, then reduce the number of votes so it fits
            my $newvotes = $maxvotesperbug;

            my $removedvotes = $oldvotes - $newvotes;

            $s = ($oldvotes == 1) ? "" : "s";
            my $oldvotestext = "You had $oldvotes vote$s on this bug.";

            $s = ($removedvotes == 1) ? "" : "s";
            my $removedvotestext = "You had $removedvotes vote$s removed from this bug.";

            my $newvotestext;
            if ($newvotes) {
                $dbh->do("UPDATE votes SET vote_count = ? " .
                         "WHERE bug_id = ? AND who = ?",
                         undef, ($newvotes, $id, $userid));
                $s = $newvotes == 1 ? "" : "s";
                $newvotestext = "You still have $newvotes vote$s on this bug."
            } else {
                $dbh->do("DELETE FROM votes WHERE bug_id = ? AND who = ?",
                         undef, ($id, $userid));
                $newvotestext = "You have no more votes remaining on this bug.";
            }

            # Notice that we did not make sure that the user fit within the $votesperuser
            # range.  This is considered to be an acceptable alternative to losing votes
            # during product moves.  Then next time the user attempts to change their votes,
            # they will be forced to fit within the $votesperuser limit.

            # Now lets send the e-mail to alert the user to the fact that their votes have
            # been reduced or removed.
            my %substs;

            $substs{"to"} = $name . Param('emailsuffix');
            $substs{"bugid"} = $id;
            $substs{"reason"} = $reason;

            $substs{"votesremoved"} = $removedvotes;
            $substs{"votesold"} = $oldvotes;
            $substs{"votesnew"} = $newvotes;

            $substs{"votesremovedtext"} = $removedvotestext;
            $substs{"votesoldtext"} = $oldvotestext;
            $substs{"votesnewtext"} = $newvotestext;

            $substs{"count"} = $removedvotes . "\n    " . $newvotestext;

            my $msg = perform_substs(Param("voteremovedmail"), \%substs);
            push(@messages, $msg);
        }
        my $votes = $dbh->selectrow_array("SELECT SUM(vote_count) " .
                                          "FROM votes WHERE bug_id = ?",
                                          undef, $id) || 0;
        $dbh->do("UPDATE bugs SET votes = ? WHERE bug_id = ?",
                 undef, ($votes, $id));
    }
    # Now return the array containing emails to be sent.
    return \@messages;
}

# If a user votes for a bug, or the number of votes required to
# confirm a bug has been reduced, check if the bug is now confirmed.
sub CheckIfVotedConfirmed {
    my ($id, $who) = (@_);
    my $dbh = Bugzilla->dbh;

    my ($votes, $status, $everconfirmed, $votestoconfirm, $timestamp) =
        $dbh->selectrow_array("SELECT votes, bug_status, everconfirmed, " .
                              "       votestoconfirm, NOW() " .
                              "FROM bugs INNER JOIN products " .
                              "                  ON products.id = bugs.product_id " .
                              "WHERE bugs.bug_id = ?",
                              undef, $id);

    my $ret = 0;
    if ($votes >= $votestoconfirm && !$everconfirmed) {
        if ($status eq 'UNCONFIRMED') {
            my $fieldid = get_field_id("bug_status");
            $dbh->do("UPDATE bugs SET bug_status = 'NEW', everconfirmed = 1, " .
                     "delta_ts = ? WHERE bug_id = ?",
                     undef, ($timestamp, $id));
            $dbh->do("INSERT INTO bugs_activity " .
                     "(bug_id, who, bug_when, fieldid, removed, added) " .
                     "VALUES (?, ?, ?, ?, ?, ?)",
                     undef, ($id, $who, $timestamp, $fieldid, 'UNCONFIRMED', 'NEW'));
        }
        else {
            $dbh->do("UPDATE bugs SET everconfirmed = 1, delta_ts = ? " .
                     "WHERE bug_id = ?", undef, ($timestamp, $id));
        }

        my $fieldid = get_field_id("everconfirmed");
        $dbh->do("INSERT INTO bugs_activity " .
                 "(bug_id, who, bug_when, fieldid, removed, added) " .
                 "VALUES (?, ?, ?, ?, ?, ?)",
                 undef, ($id, $who, $timestamp, $fieldid, '0', '1'));

        AppendComment($id, $who,
                      "*** This bug has been confirmed by popular vote. ***",
                      0, $timestamp);

        $ret = 1;
    }
    return $ret;
}

#
# Field Validation
#

# Validates and verifies a bug ID, making sure the number is a 
# positive integer, that it represents an existing bug in the
# database, and that the user is authorized to access that bug.
# We detaint the number here, too.
sub ValidateBugID {
    my ($id, $field) = @_;
    my $dbh = Bugzilla->dbh;
    my $user = Bugzilla->user;

    # Get rid of leading '#' (number) mark, if present.
    $id =~ s/^\s*#//;
    # Remove whitespace
    $id = trim($id);

    # If the ID isn't a number, it might be an alias, so try to convert it.
    my $alias = $id;
    if (!detaint_natural($id)) {
        $id = bug_alias_to_id($alias);
        $id || ThrowUserError("invalid_bug_id_or_alias",
                              {'bug_id' => $alias,
                               'field'  => $field });
    }
    
    # Modify the calling code's original variable to contain the trimmed,
    # converted-from-alias ID.
    $_[0] = $id;
    
    # First check that the bug exists
    $dbh->selectrow_array("SELECT bug_id FROM bugs WHERE bug_id = ?", undef, $id)
      || ThrowUserError("invalid_bug_id_non_existent", {'bug_id' => $id});

    return if (defined $field && ($field eq "dependson" || $field eq "blocked"));
    
    return if $user->can_see_bug($id);

    # The user did not pass any of the authorization tests, which means they
    # are not authorized to see the bug.  Display an error and stop execution.
    # The error the user sees depends on whether or not they are logged in
    # (i.e. $user->id contains the user's positive integer ID).
    if ($user->id) {
        ThrowUserError("bug_access_denied", {'bug_id' => $id});
    } else {
        ThrowUserError("bug_access_query", {'bug_id' => $id});
    }
}

# ValidateBugAlias:
#   Check that the bug alias is valid and not used by another bug.  If 
#   curr_id is specified, verify the alias is not used for any other
#   bug id.  
sub ValidateBugAlias {
    my ($alias, $curr_id) = @_;
    my $dbh = Bugzilla->dbh;

    $alias = trim($alias || "");
    trick_taint($alias);

    if ($alias eq "") {
        ThrowUserError("alias_not_defined");
    }

    # Make sure the alias isn't too long.
    if (length($alias) > 20) {
        ThrowUserError("alias_too_long");
    }

    # Make sure the alias is unique.
    my $query = "SELECT bug_id FROM bugs WHERE alias = ?";
    if (detaint_natural($curr_id)) {
        $query .= " AND bug_id != $curr_id";
    }
    my $id = $dbh->selectrow_array($query, undef, $alias); 

    my $vars = {};
    $vars->{'alias'} = $alias;
    if ($id) {
        $vars->{'bug_id'} = $id;
        ThrowUserError("alias_in_use", $vars);
    }

    # Make sure the alias isn't just a number.
    if ($alias =~ /^\d+$/) {
        ThrowUserError("alias_is_numeric", $vars);
    }

    # Make sure the alias has no commas or spaces.
    if ($alias =~ /[, ]/) {
        ThrowUserError("alias_has_comma_or_space", $vars);
    }

    $_[0] = $alias;
}

# Validate and return a hash of dependencies
sub ValidateDependencies {
    my $fields = {};
    $fields->{'dependson'} = shift;
    $fields->{'blocked'} = shift;
    my $id = shift || 0;

    unless (defined($fields->{'dependson'})
            || defined($fields->{'blocked'}))
    {
        return;
    }

    my $dbh = Bugzilla->dbh;
    my %deps;
    my %deptree;
    foreach my $pair (["blocked", "dependson"], ["dependson", "blocked"]) {
        my ($me, $target) = @{$pair};
        $deptree{$target} = [];
        $deps{$target} = [];
        next unless $fields->{$target};

        my %seen;
        foreach my $i (split('[\s,]+', $fields->{$target})) {
            if ($id == $i) {
                ThrowUserError("dependency_loop_single");
            }
            if (!exists $seen{$i}) {
                push(@{$deptree{$target}}, $i);
                $seen{$i} = 1;
            }
        }
        # populate $deps{$target} as first-level deps only.
        # and find remainder of dependency tree in $deptree{$target}
        @{$deps{$target}} = @{$deptree{$target}};
        my @stack = @{$deps{$target}};
        while (@stack) {
            my $i = shift @stack;
            my $dep_list =
                $dbh->selectcol_arrayref("SELECT $target
                                          FROM dependencies
                                          WHERE $me = ?", undef, $i);
            foreach my $t (@$dep_list) {
                # ignore any _current_ dependencies involving this bug,
                # as they will be overwritten with data from the form.
                if ($t != $id && !exists $seen{$t}) {
                    push(@{$deptree{$target}}, $t);
                    push @stack, $t;
                    $seen{$t} = 1;
                }
            }
        }
    }

    my @deps   = @{$deptree{'dependson'}};
    my @blocks = @{$deptree{'blocked'}};
    my %union = ();
    my %isect = ();
    foreach my $b (@deps, @blocks) { $union{$b}++ && $isect{$b}++ }
    my @isect = keys %isect;
    if (scalar(@isect) > 0) {
        ThrowUserError("dependency_loop_multi", {'deps' => \@isect});
    }
    return %deps;
}


#####################################################################
# Autoloaded Accessors
#####################################################################

# Determines whether an attribute access trapped by the AUTOLOAD function
# is for a valid bug attribute.  Bug attributes are properties and methods
# predefined by this module as well as bug fields for which an accessor
# can be defined by AUTOLOAD at runtime when the accessor is first accessed.
#
# XXX Strangely, some predefined attributes are on the list, but others aren't,
# and the original code didn't specify why that is.  Presumably the only
# attributes that need to be on this list are those that aren't predefined;
# we should verify that and update the list accordingly.
#
sub _validate_attribute {
    my ($attribute) = @_;

    my @valid_attributes = (
        # Miscellaneous properties and methods.
        qw(error groups
           longdescs milestoneurl attachments
           isopened isunconfirmed
           flag_types num_attachment_flag_types
           show_attachment_flags use_keywords any_flags_requesteeble),

        # Bug fields.
        Bugzilla::Bug->fields
    );

    return grep($attribute eq $_, @valid_attributes) ? 1 : 0;
}

sub AUTOLOAD {
  use vars qw($AUTOLOAD);
  my $attr = $AUTOLOAD;

  $attr =~ s/.*:://;
  return unless $attr=~ /[^A-Z]/;
  confess("invalid bug attribute $attr") unless _validate_attribute($attr);

  no strict 'refs';
  *$AUTOLOAD = sub {
      my $self = shift;
      if (defined $self->{$attr}) {
          return $self->{$attr};
      } else {
          return '';
      }
  };

  goto &$AUTOLOAD;
}

1;