summaryrefslogtreecommitdiffstats
path: root/Bugzilla/BugMail.pm
blob: d5c1c4c95bce7802c0c0673f2d3612de488c2aed (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
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

package Bugzilla::BugMail;

use 5.10.1;
use strict;
use warnings;

use Bugzilla::Error;
use Bugzilla::User;
use Bugzilla::Constants;
use Bugzilla::Util;
use Bugzilla::Bug;
use Bugzilla::Comment;
use Bugzilla::Mailer;
use Bugzilla::Hook;

use Date::Parse;
use Date::Format;
use Scalar::Util qw(blessed);
use List::MoreUtils qw(uniq firstidx);
use Sys::Hostname;
use Storable qw(dclone);

use constant BIT_DIRECT   => 1;
use constant BIT_WATCHING => 2;

sub relationships {
  my $ref = RELATIONSHIPS;

  # Clone it so that we don't modify the constant;
  my %relationships = %$ref;
  Bugzilla::Hook::process('bugmail_relationships',
    {relationships => \%relationships});
  return %relationships;
}

# This is a bit of a hack, basically keeping the old system()
# cmd line interface. Should clean this up at some point.
#
# args: bug_id, and an optional hash ref which may have keys for:
# changer, owner, qa, reporter, cc
# Optional hash contains values of people which will be forced to those
# roles when the email is sent.
# All the names are email addresses, not userids
# values are scalars, except for cc, which is a list
sub Send {
  my ($id, $forced, $params) = @_;
  $params ||= {};

  my $dbh = Bugzilla->dbh;
  my $bug = new Bugzilla::Bug($id);

  my $start = $bug->lastdiffed;
  my $end   = $dbh->selectrow_array('SELECT LOCALTIMESTAMP(0)');

  # Bugzilla::User objects of people in various roles. More than one person
  # can 'have' a role, if the person in that role has changed, or people are
  # watching.
  my @assignees = ($bug->assigned_to);
  my @qa_contacts = $bug->qa_contact || ();

  my @ccs = @{$bug->cc_users};

  # Include the people passed in as being in particular roles.
  # This can include people who used to hold those roles.
  # At this point, we don't care if there are duplicates in these arrays.
  my $changer = $forced->{'changer'};
  if ($forced->{'owner'}) {
    push(@assignees, Bugzilla::User->check($forced->{'owner'}));
  }

  if ($forced->{'qacontact'}) {
    push(@qa_contacts, Bugzilla::User->check($forced->{'qacontact'}));
  }

  if ($forced->{'cc'}) {
    foreach my $cc (@{$forced->{'cc'}}) {
      push(@ccs, Bugzilla::User->check($cc));
    }
  }
  my %user_cache = map { $_->id => $_ } (@assignees, @qa_contacts, @ccs);

  my @diffs;
  my @referenced_bugs;
  if (!$start) {
    @diffs = _get_new_bugmail_fields($bug);
  }

  if ($params->{dep_only}) {
    my $fields = Bugzilla->fields({by_name => 1});
    push(
      @diffs,
      {
        field_name => 'bug_status',
        field_desc => $fields->{bug_status}->description,
        old        => $params->{changes}->{bug_status}->[0],
        new        => $params->{changes}->{bug_status}->[1],
        login_name => $changer->login,
        blocker    => $params->{blocker}
      },
      {
        field_name => 'resolution',
        field_desc => $fields->{resolution}->description,
        old        => $params->{changes}->{resolution}->[0],
        new        => $params->{changes}->{resolution}->[1],
        login_name => $changer->login,
        blocker    => $params->{blocker}
      }
    );
    push(@referenced_bugs, $params->{blocker}->id);
  }
  else {
    my ($diffs, $referenced) = _get_diffs($bug, $end, \%user_cache);
    push(@diffs,           @$diffs);
    push(@referenced_bugs, @$referenced);
  }

  my $comments = $bug->comments({after => $start, to => $end});

  # Skip empty comments.
  @$comments = grep { $_->type || $_->body =~ /\S/ } @$comments;

  # Add duplicate bug to referenced bug list
  foreach my $comment (@$comments) {
    if ($comment->type == CMT_DUPE_OF || $comment->type == CMT_HAS_DUPE) {
      push(@referenced_bugs, $comment->extra_data);
    }
  }

  # Add dependencies to referenced bug list on new bugs
  if (!$start) {
    push @referenced_bugs, @{$bug->dependson};
    push @referenced_bugs, @{$bug->blocked};
  }

  # If no changes have been made, there is no need to process further.
  return {'sent' => []} unless scalar(@diffs) || scalar(@$comments);

  ###########################################################################
  # Start of email filtering code
  ###########################################################################

  # A user_id => roles hash to keep track of people.
  my %recipients;
  my %watching;

  # Now we work out all the people involved with this bug, and note all of
  # the relationships in a hash. The keys are userids, the values are an
  # array of role constants.

  # CCs
  $recipients{$_->id}->{+REL_CC} = BIT_DIRECT foreach (@ccs);

  # Reporter (there's only ever one)
  $recipients{$bug->reporter->id}->{+REL_REPORTER} = BIT_DIRECT;

  # QA Contact
  if (Bugzilla->params->{'useqacontact'}) {
    foreach (@qa_contacts) {

      # QA Contact can be blank; ignore it if so.
      $recipients{$_->id}->{+REL_QA} = BIT_DIRECT if $_;
    }
  }

  # Assignee
  $recipients{$_->id}->{+REL_ASSIGNEE} = BIT_DIRECT foreach (@assignees);

  # The last relevant set of people are those who are being removed from
  # their roles in this change. We get their names out of the diffs.
  foreach my $change (@diffs) {
    if ($change->{old}) {

      # You can't stop being the reporter, so we don't check that
      # relationship here.
      # Ignore people whose user account has been deleted or renamed.
      if ($change->{field_name} eq 'cc') {
        foreach my $cc_user (split(/[\s,]+/, $change->{old})) {
          my $uid = login_to_id($cc_user);
          $recipients{$uid}->{+REL_CC} = BIT_DIRECT if $uid;
        }
      }
      elsif ($change->{field_name} eq 'qa_contact') {
        my $uid = login_to_id($change->{old});
        $recipients{$uid}->{+REL_QA} = BIT_DIRECT if $uid;
      }
      elsif ($change->{field_name} eq 'assigned_to') {
        my $uid = login_to_id($change->{old});
        $recipients{$uid}->{+REL_ASSIGNEE} = BIT_DIRECT if $uid;
      }
    }
  }

  # Make sure %user_cache has every user in it so far referenced
  foreach my $user_id (keys %recipients) {
    $user_cache{$user_id} ||= new Bugzilla::User({id => $user_id, cache => 1});
  }

  Bugzilla::Hook::process(
    'bugmail_recipients',
    {
      bug        => $bug,
      recipients => \%recipients,
      users      => \%user_cache,
      diffs      => \@diffs
    }
  );

  if (scalar keys %recipients) {

    # Find all those user-watching anyone on the current list, who is not
    # on it already themselves.
    my $involved = join(",", keys %recipients);

    my $userwatchers = $dbh->selectall_arrayref(
      "SELECT watcher, watched FROM watch
                                    WHERE watched IN ($involved)"
    );

    # Mark these people as having the role of the person they are watching
    foreach my $watch (@$userwatchers) {
      while (my ($role, $bits) = each %{$recipients{$watch->[1]}}) {
        $recipients{$watch->[0]}->{$role} |= BIT_WATCHING if $bits & BIT_DIRECT;
      }
      push(@{$watching{$watch->[0]}}, $watch->[1]);
    }
  }

  # Global watcher
  my @watchers = split(/\s*,\s*/ms, Bugzilla->params->{'globalwatchers'});
  foreach (@watchers) {
    my $watcher_id = login_to_id($_);
    next unless $watcher_id;
    $recipients{$watcher_id}->{+REL_GLOBAL_WATCHER} = BIT_DIRECT;
  }

  # We now have a complete set of all the users, and their relationships to
  # the bug in question. However, we are not necessarily going to mail them
  # all - there are preferences, permissions checks and all sorts to do yet.
  my @sent;

  # The email client will display the Date: header in the desired timezone,
  # so we can always use UTC here.
  my $date = $params->{dep_only} ? $end : $bug->delta_ts;
  $date = format_time($date, '%a, %d %b %Y %T %z', 'UTC');

  # Remove duplicate references, and convert to bug objects
  @referenced_bugs = @{Bugzilla::Bug->new_from_list([uniq @referenced_bugs])};

  foreach my $user_id (keys %recipients) {
    my %rels_which_want;
    my $user = $user_cache{$user_id}
      ||= new Bugzilla::User({id => $user_id, cache => 1});

    # Deleted users must be excluded.
    next unless $user;

    # If email notifications are disabled for this account, or the bug
    # is ignored, there is no need to do additional checks.
    next if ($user->email_disabled || $user->is_bug_ignored($id));

    if ($user->can_see_bug($id)) {

      # Go through each role the user has and see if they want mail in
      # that role.
      foreach my $relationship (keys %{$recipients{$user_id}}) {
        if ($user->wants_bug_mail(
          $bug, $relationship, $start ? \@diffs : [],
          $comments, $params->{dep_only}, $changer
        ))
        {
          $rels_which_want{$relationship} = $recipients{$user_id}->{$relationship};
        }
      }
    }

    if (scalar(%rels_which_want)) {

      # So the user exists, can see the bug, and wants mail in at least
      # one role. But do we want to send it to them?

      # We shouldn't send mail if this is a dependency mail and the
      # depending bug is not visible to the user.
      # This is to avoid leaking the summary of a confidential bug.
      my $dep_ok = 1;
      if ($params->{dep_only}) {
        $dep_ok = $user->can_see_bug($params->{blocker}->id) ? 1 : 0;
      }

      # Make sure the user isn't in the nomail list, and the dep check passed.
      # BMO: never send emails to bugs or .tld addresses.  this check needs to
      # happen after the bugmail_recipients hook.
      if ($user->email_enabled && $dep_ok && ($user->login !~ /\.(?:bugs|tld)$/)) {

        # Don't show summaries for bugs the user can't access, and
        # provide a hook for extensions such as SecureMail to filter
        # this list.
        #
        # We build an array with the short_desc as a separate item to
        # allow extensions to modify the summary without touching the
        # bug object.
        my $referenced_bugs = [];
        foreach my $ref (@{$user->visible_bugs(\@referenced_bugs)}) {
          push @$referenced_bugs,
            {bug => $ref, id => $ref->id, short_desc => $ref->short_desc,};
        }
        Bugzilla::Hook::process('bugmail_referenced_bugs',
          {updated_bug => $bug, referenced_bugs => $referenced_bugs});

        my $sent_mail = sendMail({
          to              => $user,
          bug             => $bug,
          comments        => $comments,
          date            => $date,
          changer         => $changer,
          watchers        => exists $watching{$user_id} ? $watching{$user_id} : undef,
          diffs           => \@diffs,
          rels_which_want => \%rels_which_want,
          referenced_bugs => $referenced_bugs,
          dep_only        => $params->{dep_only}
        });
        push(@sent, $user->login) if $sent_mail;
      }
    }
  }

  # When sending bugmail about a blocker being reopened or resolved,
  # we say nothing about changes in the bug being blocked, so we must
  # not update lastdiffed in this case.
  if (!$params->{dep_only}) {
    $dbh->do('UPDATE bugs SET lastdiffed = ? WHERE bug_id = ?', undef, ($end, $id));
    $bug->{lastdiffed} = $end;
  }

  return {'sent' => \@sent};
}

sub sendMail {
  my $params = shift;

  my $user            = $params->{to};
  my $bug             = $params->{bug};
  my @send_comments   = @{$params->{comments}};
  my $date            = $params->{date};
  my $changer         = $params->{changer};
  my $watchingRef     = $params->{watchers};
  my @diffs           = @{$params->{diffs}};
  my $relRef          = $params->{rels_which_want};
  my $referenced_bugs = $params->{referenced_bugs};
  my $dep_only        = $params->{dep_only};
  my $attach_id;

  # Only display changes the user is allowed see.
  my @display_diffs;

  foreach my $diff (@diffs) {
    my $add_diff = 0;

    if (grep { $_ eq $diff->{field_name} } TIMETRACKING_FIELDS) {
      $add_diff = 1 if $user->is_timetracker;
    }
    elsif (!$diff->{isprivate} || $user->is_insider) {
      $add_diff = 1;
    }
    push(@display_diffs, $diff) if $add_diff;
    $attach_id = $diff->{attach_id} if $diff->{attach_id};
  }

  if (!$user->is_insider) {
    @send_comments = grep { !$_->is_private } @send_comments;
  }

  if (!scalar(@display_diffs) && !scalar(@send_comments)) {

    # Whoops, no differences!
    return 0;
  }

  my (@reasons, @reasons_watch);
  while (my ($relationship, $bits) = each %{$relRef}) {
    push(@reasons,       $relationship) if ($bits & BIT_DIRECT);
    push(@reasons_watch, $relationship) if ($bits & BIT_WATCHING);
  }

  my %relationships = relationships();
  my @headerrel     = map { $relationships{$_} } @reasons;
  my @watchingrel   = map { $relationships{$_} } @reasons_watch;
  push(@headerrel,   'None') unless @headerrel;
  push(@watchingrel, 'None') unless @watchingrel;
  push @watchingrel, map { user_id_to_login($_) } @$watchingRef;

  # BMO: Use field descriptions instead of field names in header
  my @changedfields     = uniq map { $_->{field_desc} } @display_diffs;
  my @changedfieldnames = uniq map { $_->{field_name} } @display_diffs;

  # BMO: Add a field to indicate when a comment was added
  if (grep($_->type != CMT_ATTACHMENT_CREATED, @send_comments)) {
    push(@changedfields,     'Comment Created');
    push(@changedfieldnames, 'comment');
  }

  # Add attachments.created to changedfields if one or more
  # comments contain information about a new attachment
  if (grep($_->type == CMT_ATTACHMENT_CREATED, @send_comments)) {
    push(@changedfields,     'Attachment Created');
    push(@changedfieldnames, 'attachment.created');
  }

  my $bugmailtype = "changed";
  $bugmailtype = "new"         if !$bug->lastdiffed;
  $bugmailtype = "dep_changed" if $dep_only;

  my $vars = {
    date               => $date,
    to_user            => $user,
    bug                => $bug,
    attach_id          => $attach_id,
    reasons            => \@reasons,
    reasons_watch      => \@reasons_watch,
    reasonsheader      => join(" ", @headerrel),
    reasonswatchheader => join(" ", @watchingrel),
    changer            => $changer,
    diffs              => \@display_diffs,
    changedfields      => \@changedfields,
    changedfieldnames  => \@changedfieldnames,
    new_comments       => \@send_comments,
    threadingmarker => build_thread_marker($bug->id, $user->id, !$bug->lastdiffed),
    referenced_bugs => $referenced_bugs,
    bugmailtype     => $bugmailtype,
  };

  if (Bugzilla->get_param_with_override('use_mailer_queue')) {
    enqueue($vars);
  }
  else {
    MessageToMTA(_generate_bugmail($vars));
  }

  return 1;
}

sub enqueue {
  my ($vars) = @_;

  # BMO: allow modification of the email at the time it was generated
  Bugzilla::Hook::process('bugmail_enqueue', {vars => $vars});

  # we need to flatten all objects to a hash before pushing to the job queue.
  # the hashes need to be inflated in the dequeue method.
  $vars->{bug}          = _flatten_object($vars->{bug});
  $vars->{to_user}      = _flatten_object($vars->{to_user});
  $vars->{changer}      = _flatten_object($vars->{changer});
  $vars->{new_comments} = [map { _flatten_object($_) } @{$vars->{new_comments}}];
  foreach my $diff (@{$vars->{diffs}}) {
    $diff->{who} = _flatten_object($diff->{who});
    if (exists $diff->{blocker}) {
      $diff->{blocker} = _flatten_object($diff->{blocker});
    }
  }
  foreach my $reference (@{$vars->{referenced_bugs}}) {
    $reference->{bug} = _flatten_object($reference->{bug});
  }
  Bugzilla->job_queue->insert('bug_mail', {vars => $vars});
}

sub dequeue {
  my ($payload) = @_;

  # clone the payload so we can modify it without impacting TheSchwartz's
  # ability to process the job when we've finished
  my $vars = dclone($payload);

  # inflate objects
  $vars->{bug}     = Bugzilla::Bug->new_from_hash($vars->{bug});
  $vars->{to_user} = Bugzilla::User->new_from_hash($vars->{to_user});
  $vars->{changer} = Bugzilla::User->new_from_hash($vars->{changer});
  $vars->{new_comments}
    = [map { Bugzilla::Comment->new_from_hash($_) } @{$vars->{new_comments}}];
  foreach my $diff (@{$vars->{diffs}}) {
    $diff->{who} = Bugzilla::User->new_from_hash($diff->{who});
    if (exists $diff->{blocker}) {
      $diff->{blocker} = Bugzilla::Bug->new_from_hash($diff->{blocker});
    }
  }

  # generate bugmail and send
  MessageToMTA(_generate_bugmail($vars), 1);
}

sub _flatten_object {
  my ($object) = @_;

  # nothing to do if it's already flattened
  return $object unless blessed($object);

  # the same objects are used for each recipient, so cache the flattened hash
  my $cache = Bugzilla->request_cache->{bugmail_flat_objects} ||= {};
  my $key = blessed($object) . '-' . $object->id;
  return $cache->{$key} ||= $object->flatten_to_hash;
}

sub _generate_bugmail {
  my ($vars)   = @_;
  my $user     = $vars->{to_user};
  my $template = Bugzilla->template_inner($user->setting('lang'));
  my ($msg_text, $msg_html, $msg_header);

  $template->process("email/bugmail-header.txt.tmpl", $vars, \$msg_header)
    || ThrowTemplateError($template->error());

  $template->process("email/bugmail.txt.tmpl", $vars, \$msg_text)
    || ThrowTemplateError($template->error());

  my @parts = (Email::MIME->create(
    attributes => {content_type => "text/plain",},
    body       => $msg_text,
  ));
  if ($user->setting('email_format') eq 'html') {
    $template->process("email/bugmail.html.tmpl", $vars, \$msg_html)
      || ThrowTemplateError($template->error());
    push @parts,
      Email::MIME->create(
      attributes => {content_type => "text/html",},
      body       => $msg_html,
      );
  }

  # TT trims the trailing newline, and threadingmarker may be ignored.
  my $email = new Email::MIME("$msg_header\n");

  # For tracking/diagnostic purposes, add our hostname
  $email->header_set('X-Generated-By' => hostname());

  if (scalar(@parts) == 1) {
    $email->content_type_set($parts[0]->content_type);
  }
  else {
    $email->content_type_set('multipart/alternative');
  }
  $email->parts_set(\@parts);

  # BMO: allow modification of the email given the enqueued variables
  Bugzilla::Hook::process('bugmail_generate', {vars => $vars, email => $email});

  return $email;
}

sub _get_diffs {
  my ($bug, $end, $user_cache) = @_;
  my $dbh = Bugzilla->dbh;

  my @args = ($bug->id);

  # If lastdiffed is NULL, then we don't limit the search on time.
  my $when_restriction = '';
  if ($bug->lastdiffed) {
    $when_restriction = ' AND bug_when > ? AND bug_when <= ?';
    push @args, ($bug->lastdiffed, $end);
  }

  my $diffs = $dbh->selectall_arrayref(
    "SELECT fielddefs.name AS field_name,
                   fielddefs.description AS field_desc,
                   bugs_activity.bug_when, bugs_activity.removed AS old,
                   bugs_activity.added AS new, bugs_activity.attach_id,
                   bugs_activity.comment_id, bugs_activity.who
              FROM bugs_activity
        INNER JOIN fielddefs
                ON fielddefs.id = bugs_activity.fieldid
             WHERE bugs_activity.bug_id = ?
                   $when_restriction
          ORDER BY bugs_activity.bug_when, fielddefs.description", {Slice => {}},
    @args
  );
  my $referenced_bugs = [];

  foreach my $diff (@$diffs) {
    $user_cache->{$diff->{who}}
      ||= new Bugzilla::User({id => $diff->{who}, cache => 1});
    $diff->{who} = $user_cache->{$diff->{who}};
    if ($diff->{attach_id}) {
      $diff->{isprivate}
        = $dbh->selectrow_array(
        'SELECT isprivate FROM attachments WHERE attach_id = ?',
        undef, $diff->{attach_id});
    }
    if ($diff->{field_name} eq 'longdescs.isprivate') {
      my $comment = Bugzilla::Comment->new($diff->{comment_id});
      $diff->{num}       = $comment->count;
      $diff->{isprivate} = $diff->{new};
    }
    elsif ($diff->{field_name} eq 'dependson' || $diff->{field_name} eq 'blocked') {
      push @$referenced_bugs, grep {/^\d+$/} split(/[\s,]+/, $diff->{old});
      push @$referenced_bugs, grep {/^\d+$/} split(/[\s,]+/, $diff->{new});
    }
  }

  return ($diffs, $referenced_bugs);
}

sub _get_new_bugmail_fields {
  my $bug = shift;
  my @fields = @{Bugzilla->fields({obsolete => 0, in_new_bugmail => 1})};
  my @diffs;

  # Show fields in the same order as the DEFAULT_FIELDS list, which mirrors
  # 4.0's behavour and provides sane grouping of similar fields.
  # Any additional fields are sorted by descrsiption
  my @prepend;
  foreach my $name (map { $_->{name} } Bugzilla::Field::DEFAULT_FIELDS) {
    my $idx = firstidx { $_->name eq $name } @fields;
    if ($idx != -1) {
      push(@prepend, $fields[$idx]);
      splice(@fields, $idx, 1);
    }
  }
  @fields = sort { $a->description cmp $b->description } @fields;
  @fields = (@prepend, @fields);

  foreach my $field (@fields) {
    my $name  = $field->name;
    my $value = $bug->$name;

    if (ref $value eq 'ARRAY') {
      my @new_values;
      foreach my $item (@$value) {
        if (blessed($item) && $item->isa('Bugzilla::User')) {
          push(@new_values, $item->login);
        }
        else {
          push(@new_values, $item);
        }
      }
      $value = join(', ', @new_values);
    }
    elsif (blessed($value) && $value->isa('Bugzilla::User')) {
      $value = $value->login;
    }
    elsif (blessed($value) && $value->isa('Bugzilla::Object')) {
      $value = $value->name;
    }
    elsif ($name eq 'estimated_time') {

      # "0.00" (which is what we get from the DB) is true,
      # so we explicitly do a numerical comparison with 0.
      $value = 0 if $value == 0;
    }
    elsif ($name eq 'deadline') {
      $value = time2str("%Y-%m-%d", str2time($value)) if $value;
    }

    # If there isn't anything to show, don't include this header.
    next unless $value;

    push(@diffs,
      {field_name => $name, field_desc => $field->description, new => $value});
  }

  return @diffs;
}

1;