path: root/Bugzilla/WebService/Bug.pm

# -*- 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.
#
# Contributor(s): Marc Schumann <wurblzap@gmail.com>
#                 Max Kanat-Alexander <mkanat@bugzilla.org>
#                 Mads Bondo Dydensborg <mbd@dbc.dk>
#                 Tsahi Asher <tsahi_75@yahoo.com>
#                 Noura Elhawary <nelhawar@redhat.com>
#                 Frank Becker <Frank@Frank-Becker.de>

package Bugzilla::WebService::Bug;

use strict;
use base qw(Bugzilla::WebService);

use Bugzilla::Comment;
use Bugzilla::Constants;
use Bugzilla::Error;
use Bugzilla::Field;
use Bugzilla::WebService::Constants;
use Bugzilla::WebService::Util qw(filter validate);
use Bugzilla::Bug;
use Bugzilla::BugMail;
use Bugzilla::Util qw(trick_taint trim);
use Bugzilla::Version;
use Bugzilla::Milestone;
use Bugzilla::Status;

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

use constant PRODUCT_SPECIFIC_FIELDS => qw(version target_milestone component);

use constant DATE_FIELDS => {
    comments => ['new_since'],
    search   => ['last_change_time', 'creation_time'],
};

use constant READ_ONLY => qw(
    attachments
    comments
    fields
    get
    history
    legal_values
    search
);

######################################################
# Add aliases here for old method name compatibility #
######################################################

BEGIN { 
  # In 3.0, get was called get_bugs
  *get_bugs = \&get;
  # Before 3.4rc1, "history" was get_history.
  *get_history = \&history;
}

###########
# Methods #
###########

sub fields {
    my ($self, $params) = validate(@_, 'ids', 'names');

    my @fields;
    if (defined $params->{ids}) {
        my $ids = $params->{ids};
        foreach my $id (@$ids) {
            my $loop_field = Bugzilla::Field->check({ id => $id });
            push(@fields, $loop_field);
        }
    }

    if (defined $params->{names}) {
        my $names = $params->{names};
        foreach my $field_name (@$names) {
            my $loop_field = Bugzilla::Field->check($field_name);
            # Don't push in duplicate fields if we also asked for this field
            # in "ids".
            if (!grep($_->id == $loop_field->id, @fields)) {
                push(@fields, $loop_field);
            }
        }
    }

    if (!defined $params->{ids} and !defined $params->{names}) {
        @fields = Bugzilla->get_fields({ obsolete => 0 });
    }

    my @fields_out;
    foreach my $field (@fields) {
        my $visibility_field = $field->visibility_field 
                               ? $field->visibility_field->name : undef;
        my $vis_value = $field->visibility_value; 
        my $value_field = $field->value_field
                          ? $field->value_field->name : undef;

        my (@values, $has_values);
        if ( ($field->is_select and $field->name ne 'product')
             or grep($_ eq $field->name, PRODUCT_SPECIFIC_FIELDS))
        {
             $has_values = 1;
             @values = @{ $self->_legal_field_values({ field => $field }) };
        }

        if (grep($_ eq $field->name, PRODUCT_SPECIFIC_FIELDS)) {
             $value_field = 'product';
        }

        my %field_data = (
           id                => $self->type('int', $field->id),
           type              => $self->type('int', $field->type),
           is_custom         => $self->type('boolean', $field->custom),
           name              => $self->type('string', $field->name),
           display_name      => $self->type('string', $field->description),
           is_on_bug_entry   => $self->type('boolean', $field->enter_bug),
           visibility_field  => $self->type('string', $visibility_field),
           visibility_values => [
               defined $vis_value ? $self->type('string', $vis_value->name)
                                  : ()
           ],
        );
        if ($has_values) {
           $field_data{value_field} = $self->type('string', $value_field);
           $field_data{values}      = \@values;
        };
        push(@fields_out, filter $params, \%field_data);
    }

    return { fields => \@fields_out };
}

sub _legal_field_values {
    my ($self, $params) = @_;
    my $field = $params->{field};
    my $field_name = $field->name;
    my $user = Bugzilla->user;

    my @result;
    if (grep($_ eq $field_name, PRODUCT_SPECIFIC_FIELDS)) {
        my @list;
        if ($field_name eq 'version') {
            @list = Bugzilla::Version->get_all;
        }
        elsif ($field_name eq 'component') {
            @list = Bugzilla::Component->get_all;
        }
        else {
            @list = Bugzilla::Milestone->get_all;
        }

        foreach my $value (@list) {
            my $sortkey = $field_name eq 'target_milestone'
                          ? $value->sortkey : 0;
            # XXX This is very slow for large numbers of values.
            my $product_name = $value->product->name;
            if ($user->can_see_product($product_name)) {
                push(@result, {
                    name    => $self->type('string', $value->name),
                    sortkey => $self->type('int', $sortkey),
                    visibility_values => [$self->type('string', $product_name)],
                });
            }
        }
    }

    elsif ($field_name eq 'bug_status') {
        my @status_all = Bugzilla::Status->get_all;
        foreach my $status (@status_all) {
            my @can_change_to;
            foreach my $change_to (@{ $status->can_change_to }) {
                # There's no need to note that a status can transition
                # to itself.
                next if $change_to->id == $status->id;
                my %change_to_hash = (
                    name => $self->type('string', $change_to->name),
                    comment_required => $self->type('boolean', 
                        $change_to->comment_required_on_change_from($status)),
                );
                push(@can_change_to, \%change_to_hash);
            }

            push (@result, {
               name          => $self->type('string', $status->name),
               is_open       => $self->type('boolean', $status->is_open),
               sortkey       => $self->type('int', $status->sortkey),
               can_change_to => \@can_change_to,
               visibility_values => [],
            });
        }
    }

    else {
        my @values = Bugzilla::Field::Choice->type($field)->get_all();
        foreach my $value (@values) {
            my $vis_val = $value->visibility_value;
            push(@result, {
                name              => $self->type('string', $value->name),
                sortkey           => $self->type('int'   , $value->sortkey),
                visibility_values => [
                    defined $vis_val ? $self->type('string', $vis_val->name) 
                                     : ()
                ],
            });
        }
    }

    return \@result;
}

sub comments {
    my ($self, $params) = validate(@_, 'ids', 'comment_ids');

    if (!(defined $params->{ids} || defined $params->{comment_ids})) {
        ThrowCodeError('params_required',
                       { function => 'Bug.comments',
                         params   => ['ids', 'comment_ids'] });
    }

    my $bug_ids = $params->{ids} || [];
    my $comment_ids = $params->{comment_ids} || [];

    my $dbh  = Bugzilla->dbh;
    my $user = Bugzilla->user;

    my %bugs;
    foreach my $bug_id (@$bug_ids) {
        my $bug = Bugzilla::Bug->check($bug_id);
        # We want the API to always return comments in the same order.
   
        my $comments = $bug->comments({ order => 'oldest_to_newest',
                                        after => $params->{new_since} });
        my @result;
        foreach my $comment (@$comments) {
            next if $comment->is_private && !$user->is_insider;
            push(@result, $self->_translate_comment($comment, $params));
        }
        $bugs{$bug->id}{'comments'} = \@result;
    }

    my %comments;
    if (scalar @$comment_ids) {
        my @ids = map { trim($_) } @$comment_ids;
        my $comment_data = Bugzilla::Comment->new_from_list(\@ids);

        # See if we were passed any invalid comment ids.
        my %got_ids = map { $_->id => 1 } @$comment_data;
        foreach my $comment_id (@ids) {
            if (!$got_ids{$comment_id}) {
                ThrowUserError('comment_id_invalid', { id => $comment_id });
            }
        }
 
        # Now make sure that we can see all the associated bugs.
        my %got_bug_ids = map { $_->bug_id => 1 } @$comment_data;
        Bugzilla::Bug->check($_) foreach (keys %got_bug_ids);

        foreach my $comment (@$comment_data) {
            if ($comment->is_private && !$user->is_insider) {
                ThrowUserError('comment_is_private', { id => $comment->id });
            }
            $comments{$comment->id} =
                $self->_translate_comment($comment, $params);
        }
    }

    return { bugs => \%bugs, comments => \%comments };
}

# Helper for Bug.comments
sub _translate_comment {
    my ($self, $comment, $filters) = @_;
    my $attach_id = $comment->is_about_attachment ? $comment->extra_data
                                                  : undef;
    return filter $filters, {
        id         => $self->type('int', $comment->id),
        bug_id     => $self->type('int', $comment->bug_id),
        author     => $self->type('string', $comment->author->login),
        time       => $self->type('dateTime', $comment->creation_ts),
        is_private => $self->type('boolean', $comment->is_private),
        text       => $self->type('string', $comment->body_full),
        attachment_id => $self->type('int', $attach_id),
    };
}

sub get {
    my ($self, $params) = validate(@_, 'ids');

    my $ids = $params->{ids};
    defined $ids || ThrowCodeError('param_required', { param => 'ids' });

    my @bugs;
    my @faults;
    foreach my $bug_id (@$ids) {
        my $bug;
        if ($params->{permissive}) {
            eval { $bug = Bugzilla::Bug->check($bug_id); };
            if ($@) {
                push(@faults, {id => $bug_id,
                               faultString => $@->faultstring,
                               faultCode => $@->faultcode,
                              }
                    );
                undef $@;
                next;
            }
        }
        else {
            $bug = Bugzilla::Bug->check($bug_id);
        }
        push(@bugs, $self->_bug_to_hash($bug));
    }

    return { bugs => \@bugs, faults => \@faults };
}

# this is a function that gets bug activity for list of bug ids 
# it can be called as the following:
# $call = $rpc->call( 'Bug.history', { ids => [1,2] });
sub history {
    my ($self, $params) = validate(@_, 'ids');

    my $ids = $params->{ids};
    defined $ids || ThrowCodeError('param_required', { param => 'ids' });

    my @return;

    foreach my $bug_id (@$ids) {
        my %item;
        my $bug = Bugzilla::Bug->check($bug_id);
        $bug_id = $bug->id;
        $item{id} = $self->type('int', $bug_id);

        my ($activity) = Bugzilla::Bug::GetBugActivity($bug_id);

        my @history;
        foreach my $changeset (@$activity) {
            my %bug_history;
            $bug_history{when} = $self->type('dateTime', $changeset->{when});
            $bug_history{who}  = $self->type('string', $changeset->{who});
            $bug_history{changes} = [];
            foreach my $change (@{ $changeset->{changes} }) {
                my $attach_id = delete $change->{attachid};
                if ($attach_id) {
                    $change->{attachment_id} = $self->type('int', $attach_id);
                }
                $change->{removed} = $self->type('string', $change->{removed});
                $change->{added}   = $self->type('string', $change->{added});
                $change->{field_name} = $self->type('string',
                    delete $change->{fieldname});
                push (@{$bug_history{changes}}, $change);
            }
            
            push (@history, \%bug_history);
        }

        $item{history} = \@history;

        # alias is returned in case users passes a mixture of ids and aliases
        # then they get to know which bug activity relates to which value  
        # they passed
        if (Bugzilla->params->{'usebugaliases'}) {
            $item{alias} = $self->type('string', $bug->alias);
        }
        else {
            # For API reasons, we always want the value to appear, we just
            # don't want it to have a value if aliases are turned off.
            $item{alias} = undef;
        }

        push(@return, \%item);
    }

    return { bugs => \@return };
}

sub search {
    my ($self, $params) = @_;
    
    if ( defined($params->{offset}) and !defined($params->{limit}) ) {
        ThrowCodeError('param_required', 
                       { param => 'limit', function => 'Bug.search()' });
    }
    
    $params = Bugzilla::Bug::map_fields($params);
    delete $params->{WHERE};
    
    # Do special search types for certain fields.
    if ( my $bug_when = delete $params->{delta_ts} ) {
        $params->{WHERE}->{'delta_ts >= ?'} = $bug_when;
    }
    if (my $when = delete $params->{creation_ts}) {
        $params->{WHERE}->{'creation_ts >= ?'} = $when;
    }
    if (my $summary = delete $params->{short_desc}) {
        my @strings = ref $summary ? @$summary : ($summary);
        my @likes = ("short_desc LIKE ?") x @strings;
        my $clause = join(' OR ', @likes);
        $params->{WHERE}->{"($clause)"} = [map { "\%$_\%" } @strings];
    }
    if (my $whiteboard = delete $params->{status_whiteboard}) {
        my @strings = ref $whiteboard ? @$whiteboard : ($whiteboard);
        my @likes = ("status_whiteboard LIKE ?") x @strings;
        my $clause = join(' OR ', @likes);
        $params->{WHERE}->{"($clause)"} = [map { "\%$_\%" } @strings];
    }
    
    my $bugs = Bugzilla::Bug->match($params);
    my $visible = Bugzilla->user->visible_bugs($bugs);
    my @hashes = map { $self->_bug_to_hash($_) } @$visible;
    return { bugs => \@hashes };
}

sub create {
    my ($self, $params) = @_;
    Bugzilla->login(LOGIN_REQUIRED);
    $params = Bugzilla::Bug::map_fields($params);
    my $bug = Bugzilla::Bug->create($params);
    Bugzilla::BugMail::Send($bug->bug_id, { changer => $bug->reporter });
    return { id => $self->type('int', $bug->bug_id) };
}

sub legal_values {
    my ($self, $params) = @_;
    my $field = Bugzilla::Bug::FIELD_MAP->{$params->{field}} 
                || $params->{field};

    my @global_selects = grep { !$_->is_abnormal }
                         Bugzilla->get_fields({ is_select => 1 });

    my $values;
    if (grep($_->name eq $field, @global_selects)) {
        # The field is a valid one.
        trick_taint($field);
        $values = get_legal_field_values($field);
    }
    elsif (grep($_ eq $field, PRODUCT_SPECIFIC_FIELDS)) {
        my $id = $params->{product_id};
        defined $id || ThrowCodeError('param_required',
            { function => 'Bug.legal_values', param => 'product_id' });
        grep($_->id eq $id, @{Bugzilla->user->get_accessible_products})
            || ThrowUserError('product_access_denied', { id => $id });

        my $product = new Bugzilla::Product($id);
        my @objects;
        if ($field eq 'version') {
            @objects = @{$product->versions};
        }
        elsif ($field eq 'target_milestone') {
            @objects = @{$product->milestones};
        }
        elsif ($field eq 'component') {
            @objects = @{$product->components};
        }

        $values = [map { $_->name } @objects];
    }
    else {
        ThrowCodeError('invalid_field_name', { field => $params->{field} });
    }

    my @result;
    foreach my $val (@$values) {
        push(@result, $self->type('string', $val));
    }

    return { values => \@result };
}

sub add_comment {
    my ($self, $params) = @_;
    
    #The user must login in order add a comment
    Bugzilla->login(LOGIN_REQUIRED);
    
    # Check parameters
    defined $params->{id} 
        || ThrowCodeError('param_required', { param => 'id' }); 
    my $comment = $params->{comment}; 
    (defined $comment && trim($comment) ne '')
        || ThrowCodeError('param_required', { param => 'comment' });
    
    my $bug = Bugzilla::Bug->check($params->{id});
    
    Bugzilla->user->can_edit_product($bug->product_id)
        || ThrowUserError("product_edit_denied", {product => $bug->product});
    
    # Backwards-compatibility for versions before 3.6    
    if (defined $params->{private}) {
        $params->{is_private} = delete $params->{private};
    }
    # Append comment
    $bug->add_comment($comment, { isprivate => $params->{is_private},
                                  work_time => $params->{work_time} });
    
    # Capture the call to bug->update (which creates the new comment) in 
    # a transaction so we're sure to get the correct comment_id.
    
    my $dbh = Bugzilla->dbh;
    $dbh->bz_start_transaction();
    
    $bug->update();
    
    my $new_comment_id = $dbh->bz_last_key('longdescs', 'comment_id');
    
    $dbh->bz_commit_transaction();
    
    # Send mail.
    Bugzilla::BugMail::Send($bug->bug_id, { changer => Bugzilla->user });
    
    return { id => $self->type('int', $new_comment_id) };
}

sub update_see_also {
    my ($self, $params) = @_;

    my $user = Bugzilla->login(LOGIN_REQUIRED);

    # Check parameters
    $params->{ids}
        || ThrowCodeError('param_required', { param => 'id' });
    my ($add, $remove) = @$params{qw(add remove)};
    ($add || $remove)
        or ThrowCodeError('params_required', { params => ['add', 'remove'] });

    my @bugs;
    foreach my $id (@{ $params->{ids} }) {
        my $bug = Bugzilla::Bug->check($id);
        $user->can_edit_product($bug->product_id)
            || ThrowUserError("product_edit_denied", 
                              { product => $bug->product });
        push(@bugs, $bug);
        if ($remove) {
            $bug->remove_see_also($_) foreach @$remove;
        }
        if ($add) {
            $bug->add_see_also($_) foreach @$add;
        }
    }
    
    my %changes;
    foreach my $bug (@bugs) {
        my $change = $bug->update();
        if (my $see_also = $change->{see_also}) {
            $changes{$bug->id}->{see_also} = {
                removed => [split(', ', $see_also->[0])],
                added   => [split(', ', $see_also->[1])],
            };
        }
        else {
            # We still want a changes entry, for API consistency.
            $changes{$bug->id}->{see_also} = { added => [], removed => [] };
        }

        Bugzilla::BugMail::Send($bug->id, { changer => $user });
    }

    return { changes => \%changes };
}

sub attachments {
    my ($self, $params) = validate(@_, 'ids', 'attachment_ids');

    if (!(defined $params->{ids}
          or defined $params->{attachment_ids}))
    {
        ThrowCodeError('param_required',
                       { function => 'Bug.attachments', 
                         params   => ['ids', 'attachment_ids'] });
    }

    my $ids = $params->{ids} || [];
    my $attach_ids = $params->{attachment_ids} || [];

    my %bugs;
    foreach my $bug_id (@$ids) {
        my $bug = Bugzilla::Bug->check($bug_id);
        $bugs{$bug->id} = [];
        foreach my $attach (@{$bug->attachments}) {
            push @{$bugs{$bug->id}},
                $self->_attachment_to_hash($attach, $params);
        }
    }

    my %attachments;
    foreach my $attach (@{Bugzilla::Attachment->new_from_list($attach_ids)}) {
        Bugzilla::Bug->check($attach->bug_id);
        if ($attach->isprivate && !Bugzilla->user->is_insider) {
            ThrowUserError('auth_failure', {action    => 'access',
                                            object    => 'attachment',
                                            attach_id => $attach->id});
        }
        $attachments{$attach->id} =
            $self->_attachment_to_hash($attach, $params);
    }

    return { bugs => \%bugs, attachments => \%attachments };
}

##############################
# Private Helper Subroutines #
##############################

# A helper for get() and search().
sub _bug_to_hash {
    my ($self, $bug) = @_;

    # Timetracking fields are deleted if the user doesn't belong to
    # the corresponding group.
    unless (Bugzilla->user->is_timetracker) {
        delete $bug->{'estimated_time'};
        delete $bug->{'remaining_time'};
        delete $bug->{'deadline'};
    }

    # This is done in this fashion in order to produce a stable API.
    # The internals of Bugzilla::Bug are not stable enough to just
    # return them directly.
    my %item;
    $item{'internals'}        = $bug;
    $item{'creation_time'}    = $self->type('dateTime', $bug->creation_ts);
    $item{'last_change_time'} = $self->type('dateTime', $bug->delta_ts);
    $item{'id'}               = $self->type('int', $bug->bug_id);
    $item{'summary'}          = $self->type('string', $bug->short_desc);
    $item{'assigned_to'}      = $self->type('string', $bug->assigned_to->login);
    $item{'resolution'}       = $self->type('string', $bug->resolution);
    $item{'status'}           = $self->type('string', $bug->bug_status);
    $item{'is_open'}          = $self->type('boolean', $bug->status->is_open);
    $item{'severity'}         = $self->type('string', $bug->bug_severity);
    $item{'priority'}         = $self->type('string', $bug->priority);
    $item{'product'}          = $self->type('string', $bug->product);
    $item{'component'}        = $self->type('string', $bug->component);
    $item{'dupe_of'}          = $self->type('int', $bug->dup_id);

    # if we do not delete this key, additional user info, including their
    # real name, etc, will wind up in the 'internals' hashref
    delete $item{internals}->{assigned_to_obj};

    if (Bugzilla->params->{'usebugaliases'}) {
        $item{'alias'} = $self->type('string', $bug->alias);
    }
    else {
        # For API reasons, we always want the value to appear, we just
        # don't want it to have a value if aliases are turned off.
        $item{'alias'} = undef;
    }

    return \%item;
}

sub _attachment_to_hash {
    my ($self, $attach, $filters) = @_;

    # Skipping attachment flags for now.
    delete $attach->{flags};

    my $attacher = new Bugzilla::User($attach->attacher->id);

    return filter $filters, {
        creation_time    => $self->type('dateTime', $attach->attached),
        last_change_time => $self->type('dateTime', $attach->modification_time),
        id               => $self->type('int', $attach->id),
        bug_id           => $self->type('int', $attach->bug->id),
        file_name        => $self->type('string', $attach->filename),
        description      => $self->type('string', $attach->description),
        content_type     => $self->type('string', $attach->contenttype),
        is_private       => $self->type('int', $attach->isprivate),
        is_obsolete      => $self->type('int', $attach->isobsolete),
        is_url           => $self->type('int', $attach->isurl),
        is_patch         => $self->type('int', $attach->ispatch),
        attacher         => $self->type('string', $attacher->login)
    };
}

1;

__END__

=head1 NAME

Bugzilla::Webservice::Bug - The API for creating, changing, and getting the
details of bugs.

=head1 DESCRIPTION

This part of the Bugzilla API allows you to file a new bug in Bugzilla,
or get information about bugs that have already been filed.

=head1 METHODS

See L<Bugzilla::WebService> for a description of how parameters are passed,
and what B<STABLE>, B<UNSTABLE>, and B<EXPERIMENTAL> mean.

=head2 Utility Functions

=over

=item C<fields>

B<UNSTABLE>

=over

=item B<Description>

Get information about valid bug fields, including the lists of legal values
for each field.

=item B<Params>

You can pass either field ids or field names.

B<Note>: If neither C<ids> nor C<names> is specified, then all 
non-obsolete fields will be returned.

In addition to the parameters below, this method also accepts the
standard L<include_fields|Bugzilla::WebService/include_fields> and
L<exclude_fields|Bugzilla::WebService/exclude_fields> arguments.

=over

=item C<ids>   (array) - An array of integer field ids.

=item C<names> (array) - An array of strings representing field names.

=back

=item B<Returns>

A hash containing a single element, C<fields>. This is an array of hashes,
containing the following keys:

=over

=item C<id>

C<int> An integer id uniquely idenfifying this field in this installation only.

=item C<type>

C<int> The number of the fieldtype. The following values are defined:

=over

=item C<0> Unknown

=item C<1> Free Text

=item C<2> Drop Down

=item C<3> Multiple-Selection Box

=item C<4> Large Text Box

=item C<5> Date/Time

=item C<6> Bug Id

=item C<7> Bug URLs ("See Also")

=back

=item C<is_custom>

C<boolean> True when this is a custom field, false otherwise.

=item C<name>

C<string> The internal name of this field. This is a unique identifier for
this field. If this is not a custom field, then this name will be the same
across all Bugzilla installations.

=item C<display_name>

C<string> The name of the field, as it is shown in the user interface.

=item C<is_on_bug_entry>

C<boolean> For custom fields, this is true if the field is shown when you
enter a new bug. For standard fields, this is currently always false,
even if the field shows up when entering a bug. (To know whether or not
a standard field is valid on bug entry, see L</create>.)

=item C<visibility_field>

C<string>  The name of a field that controls the visibility of this field
in the user interface. This field only appears in the user interface when
the named field is equal to one of the values in C<visibility_values>.
Can be null.

=item C<visibility_values>

C<array> of C<string>s This field is only shown when C<visibility_field>
matches one of these values. When C<visibility_field> is null,
then this is an empty array.

=item C<value_field>

C<string>  The name of the field that controls whether or not particular
values of the field are shown in the user interface. Can be null.

=item C<values>

This is an array of hashes, representing the legal values for
select-type (drop-down and multiple-selection) fields. This is also
populated for the C<component>, C<version>, and C<target_milestone>
fields, but not for the C<product> field (you must use
L<Product.get_accessible_products|Bugzilla::WebService::Product/get_accessible_products>
for that.

For fields that aren't select-type fields, this will simply be an empty
array.

Each hash has the following keys:

=over 

=item C<name>

C<string> The actual value--this is what you would specify for this
field in L</create>, etc.

=item C<sortkey>

C<int> Values, when displayed in a list, are sorted first by this integer
and then secondly by their name.

=item C<visibility_values>

If C<value_field> is defined for this field, then this value is only shown
if the C<value_field> is set to one of the values listed in this array.
Note that for per-product fields, C<value_field> is set to C<'product'>
and C<visibility_values> will reflect which product(s) this value appears in.

=item C<is_open>

C<boolean> For C<bug_status> values, determines whether this status
specifies that the bug is "open" (true) or "closed" (false). This item
is only included for the C<bug_status> field.

=item C<can_change_to>

For C<bug_status> values, this is an array of hashes that determines which
statuses you can transition to from this status. (This item is only included
for the C<bug_status> field.)

Each hash contains the following items:

=over

=item C<name>

the name of the new status

=item C<comment_required>

this C<boolean> True if a comment is required when you change a bug into
this status using this transition.

=back

=back

=back

=item B<Errors>

=over

=item 51 (Invalid Field Name or Id)

You specified an invalid field name or id.

=back

=item B<History>

=over

=item Added in Bugzilla B<3.6>.

=back

=back


=item C<legal_values> 

B<DEPRECATED> - Use L</fields> instead.

=over

=item B<Description>

Tells you what values are allowed for a particular field.

=item B<Params>

=over

=item C<field> - The name of the field you want information about.
This should be the same as the name you would use in L</create>, below.

=item C<product_id> - If you're picking a product-specific field, you have
to specify the id of the product you want the values for.

=back

=item B<Returns> 

C<values> - An array of strings: the legal values for this field.
The values will be sorted as they normally would be in Bugzilla.

=item B<Errors>

=over

=item 106 (Invalid Product)

You were required to specify a product, and either you didn't, or you
specified an invalid product (or a product that you can't access).

=item 108 (Invalid Field Name)

You specified a field that doesn't exist or isn't a drop-down field.

=back

=back


=back

=head2 Bug Information

=over


=item C<attachments>

B<EXPERIMENTAL>

=over

=item B<Description>

It allows you to get data about attachments, given a list of bugs
and/or attachment ids.

B<Note>: Private attachments will only be returned if you are in the 
insidergroup or if you are the submitter of the attachment.

=item B<Params>

B<Note>: At least one of C<ids> or C<attachment_ids> is required.

=over

=item C<ids>

See the description of the C<ids> parameter in the L</get> method.

=item C<attachment_ids>

C<array> An array of integer attachment ids.

=back

=item B<Returns>

A hash containing two elements: C<bugs> and C<attachments>. The return
value looks like this:

 {
     bugs => {
         1345 => {
             attachments => [
                 { (attachment) },
                 { (attachment) }
             ]
         },
         9874 => {
             attachments => [
                 { (attachment) },
                 { (attachment) }
             ]

         },
     },

     attachments => {
         234 => { (attachment) },
         123 => { (attachment) },
     }
 }

The attachments of any bugs that you specified in the C<ids> argument in
input are returned in C<bugs> on output. C<bugs> is a hash that has integer
bug IDs for keys and contains a single key, C<attachments>. That key points
to an arrayref that contains attachments as a hash. (Fields for attachments
are described below.)

For any attachments that you specified directly in C<attachment_ids>, they
are returned in C<attachments> on output. This is a hash where the attachment
ids point directly to hashes describing the individual attachment.

The fields for each attachment (where it says C<(attachment)> in the
diagram above) are:

=over

=item C<creation_time>

C<dateTime> The time the attachment was created.

=item C<last_change_time>

C<dateTime> The last time the attachment was modified.

=item C<id>

C<int> The numeric id of the attachment.

=item C<bug_id>

C<int> The numeric id of the bug that the attachment is attached to.

=item C<file_name>

C<string> The file name of the attachment.

=item C<description>

C<string> The description for the attachment.

=item C<content_type>

C<string> The MIME type of the attachment.

=item C<is_private>

C<boolean> True if the attachment is private (only visible to a certain
group called the "insidergroup"), False otherwise.

=item C<is_obsolete>

C<boolean> True if the attachment is obsolete, False otherwise.

=item C<is_url>

C<boolean> True if the attachment is a URL instead of actual data,
False otherwise. Note that such attachments only happen when the 
Bugzilla installation has at some point had the C<allow_attach_url>
parameter enabled.

=item C<is_patch>

C<boolean> True if the attachment is a patch, False otherwise.

=item C<attacher>

C<string> The login name of the user that created the attachment.

=back

=item B<Errors>

This method can throw all the same errors as L</get>. In addition,
it can also throw the following error:

=over

=item 304 (Auth Failure, Attachment is Private)

You specified the id of a private attachment in the C<attachment_ids>
argument, and you are not in the "insider group" that can see
private attachments.

=back

=item B<History>

=over

=item Added in Bugzilla B<3.6>.

=back

=back


=item C<comments>

B<STABLE>

=over

=item B<Description>

This allows you to get data about comments, given a list of bugs 
and/or comment ids.

=item B<Params>

B<Note>: At least one of C<ids> or C<comment_ids> is required.

In addition to the parameters below, this method also accepts the
standard L<include_fields|Bugzilla::WebService/include_fields> and
L<exclude_fields|Bugzilla::WebService/exclude_fields> arguments.

=over

=item C<ids>

C<array> An array that can contain both bug IDs and bug aliases.
All of the comments (that are visible to you) will be returned for the
specified bugs.

=item C<comment_ids> 

C<array> An array of integer comment_ids. These comments will be
returned individually, separate from any other comments in their
respective bugs.

=item C<new_since>

C<dateTime> If specified, the method will only return comments I<newer>
than this time. This only affects comments returned from the C<ids>
argument. You will always be returned all comments you request in the
C<comment_ids> argument, even if they are older than this date.

=back

=item B<Returns>

Two items are returned:

=over

=item C<bugs>

This is used for bugs specified in C<ids>. This is a hash,
where the keys are the numeric ids of the bugs, and the value is
a hash with a single key, C<comments>, which is an array of comments.
(The format of comments is described below.)

Note that any individual bug will only be returned once, so if you
specify an id multiple times in C<ids>, it will still only be
returned once.

=item C<comments>

Each individual comment requested in C<comment_ids> is returned here,
in a hash where the numeric comment id is the key, and the value
is the comment. (The format of comments is described below.) 

=back

A "comment" as described above is a hash that contains the following
keys:

=over

=item id

C<int> The globally unique ID for the comment.

=item bug_id

C<int> The ID of the bug that this comment is on.

=item attachment_id

C<int> If the comment was made on an attachment, this will be the
ID of that attachment. Otherwise it will be null.

=item text

C<string> The actual text of the comment.

=item author

C<string> The login name of the comment's author.

=item time

C<dateTime> The time (in Bugzilla's timezone) that the comment was added.

=item is_private

C<boolean> True if this comment is private (only visible to a certain
group called the "insidergroup"), False otherwise.

=back

=item B<Errors>

This method can throw all the same errors as L</get>. In addition,
it can also throw the following errors:

=over

=item 110 (Comment Is Private)

You specified the id of a private comment in the C<comment_ids>
argument, and you are not in the "insider group" that can see
private comments.

=item 111 (Invalid Comment ID)

You specified an id in the C<comment_ids> argument that is invalid--either
you specified something that wasn't a number, or there is no comment with
that id.

=back

=item B<History>

=over

=item Added in Bugzilla B<3.4>.

=item C<attachment_id> was added to the return value in Bugzilla B<3.6>.

=back

=back


=item C<get> 

B<STABLE>

=over

=item B<Description>

Gets information about particular bugs in the database.

Note: Can also be called as "get_bugs" for compatibilty with Bugzilla 3.0 API.

=item B<Params>

=over

=item C<ids>

An array of numbers and strings.

If an element in the array is entirely numeric, it represents a bug_id
from the Bugzilla database to fetch. If it contains any non-numeric 
characters, it is considered to be a bug alias instead, and the bug with 
that alias will be loaded. 

Note that it's possible for aliases to be disabled in Bugzilla, in which
case you will be told that you have specified an invalid bug_id if you
try to specify an alias. (It will be error 100.)

=item C<permissive> B<EXPERIMENTAL>

C<boolean> Normally, if you request any inaccessible or invalid bug ids,
Bug.get will throw an error. If this parameter is True, instead of throwing an
error we return an array of hashes with a C<id>, C<faultString> and C<faultCode> 
for each bug that fails, and return normal information for the other bugs that 
were accessible.

=back

=item B<Returns>

Two items are returned:

=over

=item C<bugs>

An array of hashes that contains information about the bugs with 
the valid ids. Each hash contains the following items:

=over

=item alias

C<string> The alias of this bug. If there is no alias or aliases are 
disabled in this Bugzilla, this will be an empty string.

=item assigned_to 

C<string> The login name of the user to whom the bug is assigned.

=item component

C<string> The name of the current component of this bug.

=item creation_time

C<dateTime> When the bug was created.

=item dupe_of

C<int> The bug ID of the bug that this bug is a duplicate of. If this bug 
isn't a duplicate of any bug, this will be an empty int.

=item id

C<int> The numeric bug_id of this bug.

=item internals B<DEPRECATED>

A hash. The internals of a L<Bugzilla::Bug> object. This is extremely
unstable, and you should only rely on this if you absolutely have to. The
structure of the hash may even change between point releases of Bugzilla.

This will be disappearing in a future version of Bugzilla.

=item is_open 

C<boolean> Returns true (1) if this bug is open, false (0) if it is closed.

=item last_change_time

C<dateTime> When the bug was last changed.

=item priority

C<string> The priority of the bug.

=item product

C<string> The name of the product this bug is in.

=item resolution

C<string> The current resolution of the bug, or an empty string if the bug is open. 

=item severity

C<string> The current severity of the bug.

=item status 

C<string> The current status of the bug.

=item summary

C<string> The summary of this bug.

=back

=item C<faults> B<EXPERIMENTAL>

An array of hashes that contains invalid bug ids with error messages
returned for them. Each hash contains the following items:

=over

=item id

C<int> The numeric bug_id of this bug.

=item faultString 

c<string> This will only be returned for invalid bugs if the C<permissive>
argument was set when calling Bug.get, and it is an error indicating that 
the bug id was invalid.

=item faultCode

c<int> This will only be returned for invalid bugs if the C<permissive>
argument was set when calling Bug.get, and it is the error code for the 
invalid bug error.

=back

=back

=item B<Errors>

=over

=item 100 (Invalid Bug Alias)

If you specified an alias and either: (a) the Bugzilla you're querying
doesn't support aliases or (b) there is no bug with that alias.

=item 101 (Invalid Bug ID)

The bug_id you specified doesn't exist in the database.

=item 102 (Access Denied)

You do not have access to the bug_id you specified.

=back

=item B<History>

=over

=item C<permissive> argument added to this method's params in Bugzilla B<3.4>. 

=item The following properties were added to this method's return values
in Bugzilla B<3.4>:

=over

=item For C<bugs>

=over

=item assigned_to

=item component 

=item dupe_of

=item is_open

=item priority

=item product

=item resolution

=item severity

=item status

=back 

=item C<faults>

=back 

=back


=back

=item C<history> 

B<EXPERIMENTAL>

=over

=item B<Description>

Gets the history of changes for particular bugs in the database.

=item B<Params>

=over

=item C<ids>

An array of numbers and strings.

If an element in the array is entirely numeric, it represents a bug_id 
from the Bugzilla database to fetch. If it contains any non-numeric 
characters, it is considered to be a bug alias instead, and the data bug 
with that alias will be loaded. 

Note that it's possible for aliases to be disabled in Bugzilla, in which
case you will be told that you have specified an invalid bug_id if you
try to specify an alias. (It will be error 100.)

=back

=item B<Returns>

A hash containing a single element, C<bugs>. This is an array of hashes,
containing the following keys:

=over

=item id

C<int> The numeric id of the bug.

=item alias

C<string> The alias of this bug. If there is no alias or aliases are 
disabled in this Bugzilla, this will be undef.

=item history

C<array> An array of hashes, each hash having the following keys:

=over

=item when

C<dateTime> The date the bug activity/change happened.

=item who

C<string> The login name of the user who performed the bug change.

=item changes

C<array> An array of hashes which contain all the changes that happened
to the bug at this time (as specified by C<when>). Each hash contains 
the following items:

=over

=item field_name

C<string> The name of the bug field that has changed.

=item removed

C<string> The previous value of the bug field which has been deleted 
by the change.

=item added

C<string> The new value of the bug field which has been added by the change.

=item attachment_id

C<int> The id of the attachment that was changed. This only appears if 
the change was to an attachment, otherwise C<attachment_id> will not be
present in this hash.

=back

=back

=back

=item B<Errors>

The same as L</get>.

=item B<History>

=over

=item Added in Bugzilla B<3.4>.

=back

=back


=item C<search>

B<UNSTABLE>

=over

=item B<Description>

Allows you to search for bugs based on particular criteria.

=item B<Params>

Unless otherwise specified in the description of a parameter, bugs are
returned if they match I<exactly> the criteria you specify in these 
parameters. That is, we don't match against substrings--if a bug is in
the "Widgets" product and you ask for bugs in the "Widg" product, you
won't get anything.

Criteria are joined in a logical AND. That is, you will be returned
bugs that match I<all> of the criteria, not bugs that match I<any> of
the criteria.

Each parameter can be either the type it says, or an array of the types
it says. If you pass an array, it means "Give me bugs with I<any> of
these values." For example, if you wanted bugs that were in either
the "Foo" or "Bar" products, you'd pass:

 product => ['Foo', 'Bar']

Some Bugzillas may treat your arguments case-sensitively, depending
on what database system they are using. Most commonly, though, Bugzilla is 
not case-sensitive with the arguments passed (because MySQL is the 
most-common database to use with Bugzilla, and MySQL is not case sensitive).

=over

=item C<alias>

C<string> The unique alias for this bug. Note that you can search
by alias even if the alias field is disabled in this Bugzilla, but
it's likely that there won't be any aliases set on bugs, in that case.

=item C<assigned_to>

C<string> The login name of a user that a bug is assigned to.

=item C<component>

C<string> The name of the Component that the bug is in. Note that
if there are multiple Compoonents with the same name, and you search
for that name, bugs in I<all> those Components will be returned. If you
don't want this, be sure to also specify the C<product> argument.

=item C<creation_time>

C<dateTime> Searches for bugs that were created at this time or later.
May not be an array.

=item C<id>

C<int> The numeric id of the bug.

=item C<last_change_time>

C<dateTime> Searches for bugs that were modified at this time or later.
May not be an array.

=item C<limit>

C<int> Limit the number of results returned to C<int> records.

=item C<offset>

C<int> Used in conjunction with the C<limit> argument, C<offset> defines 
the starting position for the search. For example, given a search that 
would return 100 bugs, setting C<limit> to 10 and C<offset> to 10 would return 
bugs 11 through 20 from the set of 100.

=item C<op_sys>

C<string> The "Operating System" field of a bug.

=item C<platform>

C<string> The Platform (sometimes called "Hardware") field of a bug.

=item C<priority>

C<string> The Priority field on a bug.

=item C<product>

C<string> The name of the Product that the bug is in.

=item C<reporter>

C<string> The login name of the user who reported the bug.

=item C<resolution>

C<string> The current resolution--only set if a bug is closed. You can
find open bugs by searching for bugs with an empty resolution.

=item C<severity>

C<string> The Severity field on a bug.

=item C<status>

C<string> The current status of a bug (not including its resolution,
if it has one, which is a separate field above).

=item C<summary>

C<string> Searches for substrings in the single-line Summary field on
bugs. If you specify an array, then bugs whose summaries match I<any> of the
passed substrings will be returned.

Note that unlike searching in the Bugzilla UI, substrings are not split
on spaces. So searching for C<foo bar> will match "This is a foo bar"
but not "This foo is a bar". C<['foo', 'bar']>, would, however, match
the second item.

=item C<target_milestone>

C<string> The Target Milestone field of a bug. Note that even if this
Bugzilla does not have the Target Milestone field enabled, you can
still search for bugs by Target Milestone. However, it is likely that
in that case, most bugs will not have a Target Milestone set (it
defaults to "---" when the field isn't enabled).

=item C<qa_contact>

C<string> The login name of the bug's QA Contact. Note that even if
this Bugzilla does not have the QA Contact field enabled, you can
still search for bugs by QA Contact (though it is likely that no bug
will have a QA Contact set, if the field is disabled).

=item C<url>

C<string> The "URL" field of a bug.

=item C<version>

C<string> The Version field of a bug.

=item C<whiteboard>

C<string> Search the "Status Whiteboard" field on bugs for a substring.
Works the same as the C<summary> field described above, but searches the
Status Whiteboard field.

=back

=item B<Returns>

The same as L</get>.

Note that you will only be returned information about bugs that you
can see. Bugs that you can't see will be entirely excluded from the
results. So, if you want to see private bugs, you will have to first 
log in and I<then> call this method.

=item B<Errors>

Currently, this function doesn't throw any special errors (other than
the ones that all webservice functions can throw). If you specify
an invalid value for a particular field, you just won't get any results
for that value.

=item B<History>

=over

=item Added in Bugzilla B<3.4>.

=item Searching by C<votes> was removed in Bugzilla B<3.8>.

=back

=back


=back

=head2 Bug Creation and Modification

=over


=item C<create> 

B<STABLE>

=over

=item B<Description>

This allows you to create a new bug in Bugzilla. If you specify any
invalid fields, they will be ignored. If you specify any fields you
are not allowed to set, they will just be set to their defaults or ignored.

You cannot currently set all the items here that you can set on enter_bug.cgi.

The WebService interface may allow you to set things other than those listed
here, but realize that anything undocumented is B<UNSTABLE> and will very
likely change in the future.

=item B<Params>

Some params must be set, or an error will be thrown. These params are
marked B<Required>. 

Some parameters can have defaults set in Bugzilla, by the administrator.
If these parameters have defaults set, you can omit them. These parameters
are marked B<Defaulted>.

Clients that want to be able to interact uniformly with multiple
Bugzillas should always set both the params marked B<Required> and those 
marked B<Defaulted>, because some Bugzillas may not have defaults set
for B<Defaulted> parameters, and then this method will throw an error
if you don't specify them.

The descriptions of the parameters below are what they mean when Bugzilla is
being used to track software bugs. They may have other meanings in some
installations.

=over

=item C<product> (string) B<Required> - The name of the product the bug
is being filed against.

=item C<component> (string) B<Required> - The name of a component in the
product above.

=item C<summary> (string) B<Required> - A brief description of the bug being
filed.

=item C<version> (string) B<Required> - A version of the product above;
the version the bug was found in.

=item C<description> (string) B<Defaulted> - The initial description for 
this bug. Some Bugzilla installations require this to not be blank.

=item C<op_sys> (string) B<Defaulted> - The operating system the bug was
discovered on.

=item C<platform> (string) B<Defaulted> - What type of hardware the bug was
experienced on.

=item C<priority> (string) B<Defaulted> - What order the bug will be fixed
in by the developer, compared to the developer's other bugs.

=item C<severity> (string) B<Defaulted> - How severe the bug is.

=item C<alias> (string) - A brief alias for the bug that can be used 
instead of a bug number when accessing this bug. Must be unique in
all of this Bugzilla.

=item C<assigned_to> (username) - A user to assign this bug to, if you
don't want it to be assigned to the component owner.

=item C<cc> (array) - An array of usernames to CC on this bug.

=item C<groups> (array) - An array of group names to put this
bug into. You can see valid group names on the Permissions
tab of the Preferences screen, or, if you are an administrator,
in the Groups control panel. Note that invalid group names or
groups that the bug can't be restricted to are silently ignored. If
you don't specify this argument, then a bug will be added into
all the groups that are set as being "Default" for this product. (If
you want to avoid that, you should specify C<groups> as an empty array.)

=item C<qa_contact> (username) - If this installation has QA Contacts
enabled, you can set the QA Contact here if you don't want to use
the component's default QA Contact.

=item C<status> (string) - The status that this bug should start out as.
Note that only certain statuses can be set on bug creation.

=item C<target_milestone> (string) - A valid target milestone for this
product.

=back

In addition to the above parameters, if your installation has any custom
fields, you can set them just by passing in the name of the field and
its value as a string.

=item B<Returns>

A hash with one element, C<id>. This is the id of the newly-filed bug.

=item B<Errors>

=over

=item 51 (Invalid Object)

The component you specified is not valid for this Product.

=item 103 (Invalid Alias)

The alias you specified is invalid for some reason. See the error message
for more details.

=item 104 (Invalid Field)

One of the drop-down fields has an invalid value, or a value entered in a
text field is too long. The error message will have more detail.

=item 105 (Invalid Component)

You didn't specify a component.

=item 106 (Invalid Product)

Either you didn't specify a product, this product doesn't exist, or
you don't have permission to enter bugs in this product.

=item 107 (Invalid Summary)

You didn't specify a summary for the bug.

=item 504 (Invalid User)

Either the QA Contact, Assignee, or CC lists have some invalid user
in them. The error message will have more details.

=back

=item B<History>

=over

=item Before B<3.0.4>, parameters marked as B<Defaulted> were actually
B<Required>, due to a bug in Bugzilla.

=item The C<groups> argument was added in Bugzilla B<3.8>. Before
Bugzilla 3.8, bugs were only added into Mandatory groups by this
method.

=back

=back

=item C<add_comment> 

B<STABLE>

=over

=item B<Description>

This allows you to add a comment to a bug in Bugzilla.

=item B<Params>

=over

=item C<id> (int) B<Required> - The id or alias of the bug to append a 
comment to.

=item C<comment> (string) B<Required> - The comment to append to the bug.
If this is empty or all whitespace, an error will be thrown saying that
you did not set the C<comment> parameter.

=item C<is_private> (boolean) - If set to true, the comment is private, 
otherwise it is assumed to be public.

=item C<work_time> (double) - Adds this many hours to the "Hours Worked"
on the bug. If you are not in the time tracking group, this value will
be ignored.


=back

=item B<Returns>

A hash with one element, C<id> whose value is the id of the newly-created comment.

=item B<Errors>

=over

=item 54 (Hours Worked Too Large)

You specified a C<work_time> larger than the maximum allowed value of
C<99999.99>.

=item 100 (Invalid Bug Alias) 

If you specified an alias and either: (a) the Bugzilla you're querying
doesn't support aliases or (b) there is no bug with that alias.

=item 101 (Invalid Bug ID)

The id you specified doesn't exist in the database.

=item 108 (Bug Edit Denied)

You did not have the necessary rights to edit the bug.

=item 113 (Can't Make Private Comments)

You tried to add a private comment, but don't have the necessary rights.

=item 114 (Comment Too Long)

You tried to add a comment longer than the maximum allowed length
(65,535 characters).

=back

=item B<History>

=over

=item Added in Bugzilla B<3.2>.

=item Modified to return the new comment's id in Bugzilla B<3.4>

=item Modified to throw an error if you try to add a private comment
but can't, in Bugzilla B<3.4>.

=item Before Bugzilla B<3.6>, the C<is_private> argument was called
C<private>, and you can still call it C<private> for backwards-compatibility
purposes if you wish.

=item Before Bugzilla B<3.6>, error 54 and error 114 had a generic error
code of 32000.

=back

=back


=item C<update_see_also>

B<EXPERIMENTAL>

=over

=item B<Description>

Adds or removes URLs for the "See Also" field on bugs. These URLs must
point to some valid bug in some Bugzilla installation or in Launchpad.

=item B<Params>

=over

=item C<ids>

Array of C<int>s or C<string>s. The ids or aliases of bugs that you want
to modify.

=item C<add>

Array of C<string>s. URLs to Bugzilla bugs. These URLs will be added to
the See Also field. They must be valid URLs to C<show_bug.cgi> in a
Bugzilla installation or to a bug filed at launchpad.net.

If the URLs don't start with C<http://> or C<https://>, it will be assumed
that C<http://> should be added to the beginning of the string.

It is safe to specify URLs that are already in the "See Also" field on
a bug--they will just be silently ignored.

=item C<remove>

Array of C<string>s. These URLs will be removed from the See Also field.
You must specify the full URL that you want removed. However, matching
is done case-insensitively, so you don't have to specify the URL in
exact case, if you don't want to.

If you specify a URL that is not in the See Also field of a particular bug,
it will just be silently ignored. Invaild URLs are currently silently ignored,
though this may change in some future version of Bugzilla.

=back

NOTE: If you specify the same URL in both C<add> and C<remove>, it will
be I<added>. (That is, C<add> overrides C<remove>.)

=item B<Returns>

C<changes>, a hash where the keys are numeric bug ids and the contents
are a hash with one key, C<see_also>. C<see_also> points to a hash, which
contains two keys, C<added> and C<removed>. These are arrays of strings,
representing the actual changes that were made to the bug.

Here's a diagram of what the return value looks like for updating
bug ids 1 and 2:

 {
   changes => {
       1 => {
           see_also => {
               added   => (an array of bug URLs),
               removed => (an array of bug URLs),
           }
       },
       2 => {
           see_also => {
               added   => (an array of bug URLs),
               removed => (an array of bug URLs),
           }
       }
   }
 }

This return value allows you to tell what this method actually did. It is in
this format to be compatible with the return value of a future C<Bug.update>
method.

=item B<Errors>

This method can throw all of the errors that L</get> throws, plus:

=over

=item 108 (Bug Edit Denied)

You did not have the necessary rights to edit the bug.

=item 112 (Invalid Bug URL)

One of the URLs you provided did not look like a valid bug URL.

=item 115 (See Also Edit Denied)

You did not have the necessary rights to edit the See Also field for
this bug.

=back

=item B<History>

=over

=item Added in Bugzilla B<3.4>.

=item Before Bugzilla B<3.6>, error 115 had a generic error code of 32000.

=back

=back


=back