Remove useless comments from search output

[mediawiki.git] / includes / specials / SpecialContributions.php

<?php
/**
 * Implements Special:Contributions
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup SpecialPage
 */

/**
 * Special:Contributions, show user contributions in a paged list
 *
 * @ingroup SpecialPage
 */
class SpecialContributions extends IncludableSpecialPage {
        protected $opts;

        public function __construct() {
                parent::__construct( 'Contributions' );
        }

        public function execute( $par ) {
                $this->setHeaders();
                $this->outputHeader();
                $out = $this->getOutput();
                $out->addModuleStyles( 'mediawiki.special' );

                $this->opts = array();
                $request = $this->getRequest();

                if ( $par !== null ) {
                        $target = $par;
                } else {
                        $target = $request->getVal( 'target' );
                }

                // check for radiobox
                if ( $request->getVal( 'contribs' ) == 'newbie' ) {
                        $target = 'newbies';
                        $this->opts['contribs'] = 'newbie';
                } elseif ( $par === 'newbies' ) { // b/c for WMF
                        $target = 'newbies';
                        $this->opts['contribs'] = 'newbie';
                } else {
                        $this->opts['contribs'] = 'user';
                }

                $this->opts['deletedOnly'] = $request->getBool( 'deletedOnly' );

                if ( !strlen( $target ) ) {
                        if ( !$this->including() ) {
                                $out->addHTML( $this->getForm() );
                        }

                        return;
                }

                $user = $this->getUser();

                $this->opts['limit'] = $request->getInt( 'limit', $user->getOption( 'rclimit' ) );
                $this->opts['target'] = $target;
                $this->opts['topOnly'] = $request->getBool( 'topOnly' );
                $this->opts['newOnly'] = $request->getBool( 'newOnly' );

                $nt = Title::makeTitleSafe( NS_USER, $target );
                if ( !$nt ) {
                        $out->addHTML( $this->getForm() );

                        return;
                }
                $userObj = User::newFromName( $nt->getText(), false );
                if ( !$userObj ) {
                        $out->addHTML( $this->getForm() );

                        return;
                }
                $id = $userObj->getID();

                if ( $this->opts['contribs'] != 'newbie' ) {
                        $target = $nt->getText();
                        $out->addSubtitle( $this->contributionsSub( $userObj ) );
                        $out->setHTMLTitle( $this->msg(
                                'pagetitle',
                                $this->msg( 'contributions-title', $target )->plain()
                        )->inContentLanguage() );
                        $this->getSkin()->setRelevantUser( $userObj );
                } else {
                        $out->addSubtitle( $this->msg( 'sp-contributions-newbies-sub' ) );
                        $out->setHTMLTitle( $this->msg(
                                'pagetitle',
                                $this->msg( 'sp-contributions-newbies-title' )->plain()
                        )->inContentLanguage() );
                }

                if ( ( $ns = $request->getVal( 'namespace', null ) ) !== null && $ns !== '' ) {
                        $this->opts['namespace'] = intval( $ns );
                } else {
                        $this->opts['namespace'] = '';
                }

                $this->opts['associated'] = $request->getBool( 'associated' );
                $this->opts['nsInvert'] = (bool)$request->getVal( 'nsInvert' );
                $this->opts['tagfilter'] = (string)$request->getVal( 'tagfilter' );

                // Allows reverts to have the bot flag in recent changes. It is just here to
                // be passed in the form at the top of the page
                if ( $user->isAllowed( 'markbotedits' ) && $request->getBool( 'bot' ) ) {
                        $this->opts['bot'] = '1';
                }

                $skip = $request->getText( 'offset' ) || $request->getText( 'dir' ) == 'prev';
                # Offset overrides year/month selection
                if ( $skip ) {
                        $this->opts['year'] = '';
                        $this->opts['month'] = '';
                } else {
                        $this->opts['year'] = $request->getIntOrNull( 'year' );
                        $this->opts['month'] = $request->getIntOrNull( 'month' );
                }

                $feedType = $request->getVal( 'feed' );

                $feedParams = array(
                        'action' => 'feedcontributions',
                        'user' => $target,
                );
                if ( $this->opts['topOnly'] ) {
                        $feedParams['toponly'] = true;
                }
                if ( $this->opts['newOnly'] ) {
                        $feedParams['newonly'] = true;
                }
                if ( $this->opts['deletedOnly'] ) {
                        $feedParams['deletedonly'] = true;
                }
                if ( $this->opts['tagfilter'] !== '' ) {
                        $feedParams['tagfilter'] = $this->opts['tagfilter'];
                }
                if ( $this->opts['namespace'] !== '' ) {
                        $feedParams['namespace'] = $this->opts['namespace'];
                }
                // Don't use year and month for the feed URL, but pass them on if
                // we redirect to API (if $feedType is specified)
                if ( $feedType && $this->opts['year'] !== null ) {
                        $feedParams['year'] = $this->opts['year'];
                }
                if ( $feedType && $this->opts['month'] !== null ) {
                        $feedParams['month'] = $this->opts['month'];
                }

                if ( $feedType ) {
                        // Maintain some level of backwards compatability
                        // If people request feeds using the old parameters, redirect to API
                        $feedParams['feedformat'] = $feedType;
                        $url = wfAppendQuery( wfScript( 'api' ), $feedParams );

                        $out->redirect( $url, '301' );

                        return;
                }

                // Add RSS/atom links
                $this->addFeedLinks( $feedParams );

                if ( wfRunHooks( 'SpecialContributionsBeforeMainOutput', array( $id, $userObj, $this ) ) ) {
                        if ( !$this->including() ) {
                                $out->addHTML( $this->getForm() );
                        }
                        $pager = new ContribsPager( $this->getContext(), array(
                                'target' => $target,
                                'contribs' => $this->opts['contribs'],
                                'namespace' => $this->opts['namespace'],
                                'tagfilter' => $this->opts['tagfilter'],
                                'year' => $this->opts['year'],
                                'month' => $this->opts['month'],
                                'deletedOnly' => $this->opts['deletedOnly'],
                                'topOnly' => $this->opts['topOnly'],
                                'newOnly' => $this->opts['newOnly'],
                                'nsInvert' => $this->opts['nsInvert'],
                                'associated' => $this->opts['associated'],
                        ) );

                        if ( !$pager->getNumRows() ) {
                                $out->addWikiMsg( 'nocontribs', $target );
                        } else {
                                # Show a message about slave lag, if applicable
                                $lag = wfGetLB()->safeGetLag( $pager->getDatabase() );
                                if ( $lag > 0 ) {
                                        $out->showLagWarning( $lag );
                                }

                                $out->addHTML(
                                        '<p>' . $pager->getNavigationBar() . '</p>' .
                                                $pager->getBody() .
                                                '<p>' . $pager->getNavigationBar() . '</p>'
                                );
                        }
                        $out->preventClickjacking( $pager->getPreventClickjacking() );

                        # Show the appropriate "footer" message - WHOIS tools, etc.
                        if ( $this->opts['contribs'] == 'newbie' ) {
                                $message = 'sp-contributions-footer-newbies';
                        } elseif ( IP::isIPAddress( $target ) ) {
                                $message = 'sp-contributions-footer-anon';
                        } elseif ( $userObj->isAnon() ) {
                                // No message for non-existing users
                                $message = '';
                        } else {
                                $message = 'sp-contributions-footer';
                        }

                        if ( $message ) {
                                if ( !$this->including() ) {
                                        if ( !$this->msg( $message, $target )->isDisabled() ) {
                                                $out->wrapWikiMsg(
                                                        "<div class='mw-contributions-footer'>\n$1\n</div>",
                                                        array( $message, $target ) );
                                        }
                                }
                        }
                }
        }

        /**
         * Generates the subheading with links
         * @param User $userObj User object for the target
         * @return string Appropriately-escaped HTML to be output literally
         * @todo FIXME: Almost the same as getSubTitle in SpecialDeletedContributions.php.
         * Could be combined.
         */
        protected function contributionsSub( $userObj ) {
                if ( $userObj->isAnon() ) {
                        // Show a warning message that the user being searched for doesn't exists
                        if ( !User::isIP( $userObj->getName() ) ) {
                                $this->getOutput()->wrapWikiMsg(
                                        "<div class=\"mw-userpage-userdoesnotexist error\">\n\$1\n</div>",
                                        array(
                                                'contributions-userdoesnotexist',
                                                wfEscapeWikiText( $userObj->getName() ),
                                        )
                                );
                        }
                        $user = htmlspecialchars( $userObj->getName() );
                } else {
                        $user = Linker::link( $userObj->getUserPage(), htmlspecialchars( $userObj->getName() ) );
                }
                $nt = $userObj->getUserPage();
                $talk = $userObj->getTalkPage();
                $links = '';
                if ( $talk ) {
                        $tools = $this->getUserLinks( $nt, $talk, $userObj );
                        $links = $this->getLanguage()->pipeList( $tools );

                        // Show a note if the user is blocked and display the last block log entry.
                        // Do not expose the autoblocks, since that may lead to a leak of accounts' IPs,
                        // and also this will display a totally irrelevant log entry as a current block.
                        if ( $userObj->isBlocked() && $userObj->getBlock()->getType() != Block::TYPE_AUTO ) {
                                $out = $this->getOutput(); // showLogExtract() wants first parameter by reference
                                LogEventsList::showLogExtract(
                                        $out,
                                        'block',
                                        $nt,
                                        '',
                                        array(
                                                'lim' => 1,
                                                'showIfEmpty' => false,
                                                'msgKey' => array(
                                                        $userObj->isAnon() ?
                                                                'sp-contributions-blocked-notice-anon' :
                                                                'sp-contributions-blocked-notice',
                                                        $userObj->getName() # Support GENDER in 'sp-contributions-blocked-notice'
                                                ),
                                                'offset' => '' # don't use WebRequest parameter offset
                                        )
                                );
                        }
                }

                return $this->msg( 'contribsub2' )->rawParams( $user, $links )->params( $userObj->getName() );
        }

        /**
         * Links to different places.
         * @param Title $userpage Target user page
         * @param Title $talkpage Talk page
         * @param User $target Target user object
         * @return array
         */
        public function getUserLinks( Title $userpage, Title $talkpage, User $target ) {

                $id = $target->getId();
                $username = $target->getName();

                $tools[] = Linker::link( $talkpage, $this->msg( 'sp-contributions-talk' )->escaped() );

                if ( ( $id !== null ) || ( $id === null && IP::isIPAddress( $username ) ) ) {
                        if ( $this->getUser()->isAllowed( 'block' ) ) { # Block / Change block / Unblock links
                                if ( $target->isBlocked() && $target->getBlock()->getType() != Block::TYPE_AUTO ) {
                                        $tools[] = Linker::linkKnown( # Change block link
                                                SpecialPage::getTitleFor( 'Block', $username ),
                                                $this->msg( 'change-blocklink' )->escaped()
                                        );
                                        $tools[] = Linker::linkKnown( # Unblock link
                                                SpecialPage::getTitleFor( 'Unblock', $username ),
                                                $this->msg( 'unblocklink' )->escaped()
                                        );
                                } else { # User is not blocked
                                        $tools[] = Linker::linkKnown( # Block link
                                                SpecialPage::getTitleFor( 'Block', $username ),
                                                $this->msg( 'blocklink' )->escaped()
                                        );
                                }
                        }

                        # Block log link
                        $tools[] = Linker::linkKnown(
                                SpecialPage::getTitleFor( 'Log', 'block' ),
                                $this->msg( 'sp-contributions-blocklog' )->escaped(),
                                array(),
                                array( 'page' => $userpage->getPrefixedText() )
                        );

                        # Suppression log link (bug 59120)
                        if ( $this->getUser()->isAllowed( 'suppressionlog' ) ) {
                                $tools[] = Linker::linkKnown(
                                        SpecialPage::getTitleFor( 'Log', 'suppress' ),
                                        $this->msg( 'sp-contributions-suppresslog' )->escaped(),
                                        array(),
                                        array( 'offender' => $username )
                                );
                        }
                }
                # Uploads
                $tools[] = Linker::linkKnown(
                        SpecialPage::getTitleFor( 'Listfiles', $username ),
                        $this->msg( 'sp-contributions-uploads' )->escaped()
                );

                # Other logs link
                $tools[] = Linker::linkKnown(
                        SpecialPage::getTitleFor( 'Log', $username ),
                        $this->msg( 'sp-contributions-logs' )->escaped()
                );

                # Add link to deleted user contributions for priviledged users
                if ( $this->getUser()->isAllowed( 'deletedhistory' ) ) {
                        $tools[] = Linker::linkKnown(
                                SpecialPage::getTitleFor( 'DeletedContributions', $username ),
                                $this->msg( 'sp-contributions-deleted' )->escaped()
                        );
                }

                # Add a link to change user rights for privileged users
                $userrightsPage = new UserrightsPage();
                $userrightsPage->setContext( $this->getContext() );
                if ( $userrightsPage->userCanChangeRights( $target ) ) {
                        $tools[] = Linker::linkKnown(
                                SpecialPage::getTitleFor( 'Userrights', $username ),
                                $this->msg( 'sp-contributions-userrights' )->escaped()
                        );
                }

                wfRunHooks( 'ContributionsToolLinks', array( $id, $userpage, &$tools ) );

                return $tools;
        }

        /**
         * Generates the namespace selector form with hidden attributes.
         * @return string HTML fragment
         */
        protected function getForm() {
                global $wgScript;

                $this->opts['title'] = $this->getPageTitle()->getPrefixedText();
                if ( !isset( $this->opts['target'] ) ) {
                        $this->opts['target'] = '';
                } else {
                        $this->opts['target'] = str_replace( '_', ' ', $this->opts['target'] );
                }

                if ( !isset( $this->opts['namespace'] ) ) {
                        $this->opts['namespace'] = '';
                }

                if ( !isset( $this->opts['nsInvert'] ) ) {
                        $this->opts['nsInvert'] = '';
                }

                if ( !isset( $this->opts['associated'] ) ) {
                        $this->opts['associated'] = false;
                }

                if ( !isset( $this->opts['contribs'] ) ) {
                        $this->opts['contribs'] = 'user';
                }

                if ( !isset( $this->opts['year'] ) ) {
                        $this->opts['year'] = '';
                }

                if ( !isset( $this->opts['month'] ) ) {
                        $this->opts['month'] = '';
                }

                if ( $this->opts['contribs'] == 'newbie' ) {
                        $this->opts['target'] = '';
                }

                if ( !isset( $this->opts['tagfilter'] ) ) {
                        $this->opts['tagfilter'] = '';
                }

                if ( !isset( $this->opts['topOnly'] ) ) {
                        $this->opts['topOnly'] = false;
                }

                if ( !isset( $this->opts['newOnly'] ) ) {
                        $this->opts['newOnly'] = false;
                }

                $form = Html::openElement(
                        'form',
                        array(
                                'method' => 'get',
                                'action' => $wgScript,
                                'class' => 'mw-contributions-form'
                        )
                );

                # Add hidden params for tracking except for parameters in $skipParameters
                $skipParameters = array(
                        'namespace',
                        'nsInvert',
                        'deletedOnly',
                        'target',
                        'contribs',
                        'year',
                        'month',
                        'topOnly',
                        'newOnly',
                        'associated'
                );

                foreach ( $this->opts as $name => $value ) {
                        if ( in_array( $name, $skipParameters ) ) {
                                continue;
                        }
                        $form .= "\t" . Html::hidden( $name, $value ) . "\n";
                }

                $tagFilter = ChangeTags::buildTagFilterSelector( $this->opts['tagfilter'] );

                if ( $tagFilter ) {
                        $filterSelection = Html::rawElement(
                                'td',
                                array( 'class' => 'mw-label' ),
                                array_shift( $tagFilter )
                        );
                        $filterSelection .= Html::rawElement(
                                'td',
                                array( 'class' => 'mw-input' ),
                                implode( '&#160', $tagFilter )
                        );
                } else {
                        $filterSelection = Html::rawElement( 'td', array( 'colspan' => 2 ), '' );
                }

                $labelNewbies = Xml::radioLabel(
                        $this->msg( 'sp-contributions-newbies' )->text(),
                        'contribs',
                        'newbie',
                        'newbie',
                        $this->opts['contribs'] == 'newbie',
                        array( 'class' => 'mw-input' )
                );
                $labelUsername = Xml::radioLabel(
                        $this->msg( 'sp-contributions-username' )->text(),
                        'contribs',
                        'user',
                        'user',
                        $this->opts['contribs'] == 'user',
                        array( 'class' => 'mw-input' )
                );
                $input = Html::input(
                        'target',
                        $this->opts['target'],
                        'text',
                        array( 'size' => '40', 'required' => '', 'class' => 'mw-input' ) +
                                ( $this->opts['target'] ? array() : array( 'autofocus' )
                                )
                );
                $targetSelection = Html::rawElement(
                        'td',
                        array( 'colspan' => 2 ),
                        $labelNewbies . '<br />' . $labelUsername . ' ' . $input . ' '
                );

                $namespaceSelection = Xml::tags(
                        'td',
                        array( 'class' => 'mw-label' ),
                        Xml::label(
                                $this->msg( 'namespace' )->text(),
                                'namespace',
                                ''
                        )
                );
                $namespaceSelection .= Html::rawElement(
                        'td',
                        null,
                        Html::namespaceSelector(
                                array( 'selected' => $this->opts['namespace'], 'all' => '' ),
                                array(
                                        'name' => 'namespace',
                                        'id' => 'namespace',
                                        'class' => 'namespaceselector',
                                )
                        ) . '&#160;' .
                                Html::rawElement(
                                        'span',
                                        array( 'style' => 'white-space: nowrap' ),
                                        Xml::checkLabel(
                                                $this->msg( 'invert' )->text(),
                                                'nsInvert',
                                                'nsInvert',
                                                $this->opts['nsInvert'],
                                                array(
                                                        'title' => $this->msg( 'tooltip-invert' )->text(),
                                                        'class' => 'mw-input'
                                                )
                                        ) . '&#160;'
                                ) .
                                Html::rawElement( 'span', array( 'style' => 'white-space: nowrap' ),
                                        Xml::checkLabel(
                                                $this->msg( 'namespace_association' )->text(),
                                                'associated',
                                                'associated',
                                                $this->opts['associated'],
                                                array(
                                                        'title' => $this->msg( 'tooltip-namespace_association' )->text(),
                                                        'class' => 'mw-input'
                                                )
                                        ) . '&#160;'
                                )
                );

                if ( $this->getUser()->isAllowed( 'deletedhistory' ) ) {
                        $deletedOnlyCheck = Html::rawElement(
                                'span',
                                array( 'style' => 'white-space: nowrap' ),
                                Xml::checkLabel(
                                        $this->msg( 'history-show-deleted' )->text(),
                                        'deletedOnly',
                                        'mw-show-deleted-only',
                                        $this->opts['deletedOnly'],
                                        array( 'class' => 'mw-input' )
                                )
                        );
                } else {
                        $deletedOnlyCheck = '';
                }

                $checkLabelTopOnly = Html::rawElement(
                        'span',
                        array( 'style' => 'white-space: nowrap' ),
                        Xml::checkLabel(
                                $this->msg( 'sp-contributions-toponly' )->text(),
                                'topOnly',
                                'mw-show-top-only',
                                $this->opts['topOnly'],
                                array( 'class' => 'mw-input' )
                        )
                );
                $checkLabelNewOnly = Html::rawElement(
                        'span',
                        array( 'style' => 'white-space: nowrap' ),
                        Xml::checkLabel(
                                $this->msg( 'sp-contributions-newonly' )->text(),
                                'newOnly',
                                'mw-show-new-only',
                                $this->opts['newOnly'],
                                array( 'class' => 'mw-input' )
                        )
                );
                $extraOptions = Html::rawElement(
                        'td',
                        array( 'colspan' => 2 ),
                        $deletedOnlyCheck . $checkLabelTopOnly . $checkLabelNewOnly
                );

                $dateSelectionAndSubmit = Xml::tags( 'td', array( 'colspan' => 2 ),
                        Xml::dateMenu(
                                $this->opts['year'] === '' ? MWTimestamp::getInstance()->format( 'Y' ) : $this->opts['year'],
                                $this->opts['month']
                        ) . ' ' .
                                Xml::submitButton(
                                        $this->msg( 'sp-contributions-submit' )->text(),
                                        array( 'class' => 'mw-submit' )
                                )
                );

                $form .= Xml::fieldset( $this->msg( 'sp-contributions-search' )->text() );
                $form .= Html::rawElement( 'table', array( 'class' => 'mw-contributions-table' ), "\n" .
                        Html::rawElement( 'tr', array(), $targetSelection ) . "\n" .
                        Html::rawElement( 'tr', array(), $namespaceSelection ) . "\n" .
                        Html::rawElement( 'tr', array(), $filterSelection ) . "\n" .
                        Html::rawElement( 'tr', array(), $extraOptions ) . "\n" .
                        Html::rawElement( 'tr', array(), $dateSelectionAndSubmit ) . "\n"
                );

                $explain = $this->msg( 'sp-contributions-explain' );
                if ( !$explain->isBlank() ) {
                        $form .= "<p id='mw-sp-contributions-explain'>{$explain->parse()}</p>";
                }

                $form .= Xml::closeElement( 'fieldset' ) . Xml::closeElement( 'form' );

                return $form;
        }

        protected function getGroupName() {
                return 'users';
        }
}

/**
 * Pager for Special:Contributions
 * @ingroup SpecialPage Pager
 */
class ContribsPager extends ReverseChronologicalPager {
        public $mDefaultDirection = true;
        public $messages;
        public $target;
        public $namespace = '';
        public $mDb;
        public $preventClickjacking = false;

        /** @var DatabaseBase */
        public $mDbSecondary;

        /**
         * @var array
         */
        protected $mParentLens;

        function __construct( IContextSource $context, array $options ) {
                parent::__construct( $context );

                $msgs = array(
                        'diff',
                        'hist',
                        'newarticle',
                        'pipe-separator',
                        'rev-delundel',
                        'rollbacklink',
                        'uctop'
                );

                foreach ( $msgs as $msg ) {
                        $this->messages[$msg] = $this->msg( $msg )->escaped();
                }

                $this->target = isset( $options['target'] ) ? $options['target'] : '';
                $this->contribs = isset( $options['contribs'] ) ? $options['contribs'] : 'users';
                $this->namespace = isset( $options['namespace'] ) ? $options['namespace'] : '';
                $this->tagFilter = isset( $options['tagfilter'] ) ? $options['tagfilter'] : false;
                $this->nsInvert = isset( $options['nsInvert'] ) ? $options['nsInvert'] : false;
                $this->associated = isset( $options['associated'] ) ? $options['associated'] : false;

                $this->deletedOnly = !empty( $options['deletedOnly'] );
                $this->topOnly = !empty( $options['topOnly'] );
                $this->newOnly = !empty( $options['newOnly'] );

                $year = isset( $options['year'] ) ? $options['year'] : false;
                $month = isset( $options['month'] ) ? $options['month'] : false;
                $this->getDateCond( $year, $month );

                // Most of this code will use the 'contributions' group DB, which can map to slaves
                // with extra user based indexes or partioning by user. The additional metadata
                // queries should use a regular slave since the lookup pattern is not all by user.
                $this->mDbSecondary = wfGetDB( DB_SLAVE ); // any random slave
                $this->mDb = wfGetDB( DB_SLAVE, 'contributions' );
        }

        function getDefaultQuery() {
                $query = parent::getDefaultQuery();
                $query['target'] = $this->target;

                return $query;
        }

        /**
         * This method basically executes the exact same code as the parent class, though with
         * a hook added, to allow extentions to add additional queries.
         *
         * @param string $offset Index offset, inclusive
         * @param int $limit Exact query limit
         * @param bool $descending Query direction, false for ascending, true for descending
         * @return ResultWrapper
         */
        function reallyDoQuery( $offset, $limit, $descending ) {
                list( $tables, $fields, $conds, $fname, $options, $join_conds ) = $this->buildQueryInfo(
                        $offset,
                        $limit,
                        $descending
                );
                $pager = $this;

                /*
                 * This hook will allow extensions to add in additional queries, so they can get their data
                 * in My Contributions as well. Extensions should append their results to the $data array.
                 *
                 * Extension queries have to implement the navbar requirement as well. They should
                 * - have a column aliased as $pager->getIndexField()
                 * - have LIMIT set
                 * - have a WHERE-clause that compares the $pager->getIndexField()-equivalent column to the offset
                 * - have the ORDER BY specified based upon the details provided by the navbar
                 *
                 * See includes/Pager.php buildQueryInfo() method on how to build LIMIT, WHERE & ORDER BY
                 *
                 * &$data: an array of results of all contribs queries
                 * $pager: the ContribsPager object hooked into
                 * $offset: see phpdoc above
                 * $limit: see phpdoc above
                 * $descending: see phpdoc above
                 */
                $data = array( $this->mDb->select(
                        $tables, $fields, $conds, $fname, $options, $join_conds
                ) );
                wfRunHooks(
                        'ContribsPager::reallyDoQuery',
                        array( &$data, $pager, $offset, $limit, $descending )
                );

                $result = array();

                // loop all results and collect them in an array
                foreach ( $data as $query ) {
                        foreach ( $query as $i => $row ) {
                                // use index column as key, allowing us to easily sort in PHP
                                $result[$row->{$this->getIndexField()} . "-$i"] = $row;
                        }
                }

                // sort results
                if ( $descending ) {
                        ksort( $result );
                } else {
                        krsort( $result );
                }

                // enforce limit
                $result = array_slice( $result, 0, $limit );

                // get rid of array keys
                $result = array_values( $result );

                return new FakeResultWrapper( $result );
        }

        function getQueryInfo() {
                list( $tables, $index, $userCond, $join_cond ) = $this->getUserCond();

                $user = $this->getUser();
                $conds = array_merge( $userCond, $this->getNamespaceCond() );

                // Paranoia: avoid brute force searches (bug 17342)
                if ( !$user->isAllowed( 'deletedhistory' ) ) {
                        $conds[] = $this->mDb->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0';
                } elseif ( !$user->isAllowed( 'suppressrevision' ) ) {
                        $conds[] = $this->mDb->bitAnd( 'rev_deleted', Revision::SUPPRESSED_USER ) .
                                ' != ' . Revision::SUPPRESSED_USER;
                }

                # Don't include orphaned revisions
                $join_cond['page'] = Revision::pageJoinCond();
                # Get the current user name for accounts
                $join_cond['user'] = Revision::userJoinCond();

                $options = array();
                if ( $index ) {
                        $options['USE INDEX'] = array( 'revision' => $index );
                }

                $queryInfo = array(
                        'tables' => $tables,
                        'fields' => array_merge(
                                Revision::selectFields(),
                                Revision::selectUserFields(),
                                array( 'page_namespace', 'page_title', 'page_is_new',
                                        'page_latest', 'page_is_redirect', 'page_len' )
                        ),
                        'conds' => $conds,
                        'options' => $options,
                        'join_conds' => $join_cond
                );

                ChangeTags::modifyDisplayQuery(
                        $queryInfo['tables'],
                        $queryInfo['fields'],
                        $queryInfo['conds'],
                        $queryInfo['join_conds'],
                        $queryInfo['options'],
                        $this->tagFilter
                );

                wfRunHooks( 'ContribsPager::getQueryInfo', array( &$this, &$queryInfo ) );

                return $queryInfo;
        }

        function getUserCond() {
                $condition = array();
                $join_conds = array();
                $tables = array( 'revision', 'page', 'user' );
                $index = false;
                if ( $this->contribs == 'newbie' ) {
                        $max = $this->mDb->selectField( 'user', 'max(user_id)', false, __METHOD__ );
                        $condition[] = 'rev_user >' . (int)( $max - $max / 100 );
                        # ignore local groups with the bot right
                        # @todo FIXME: Global groups may have 'bot' rights
                        $groupsWithBotPermission = User::getGroupsWithPermission( 'bot' );
                        if ( count( $groupsWithBotPermission ) ) {
                                $tables[] = 'user_groups';
                                $condition[] = 'ug_group IS NULL';
                                $join_conds['user_groups'] = array(
                                        'LEFT JOIN', array(
                                                'ug_user = rev_user',
                                                'ug_group' => $groupsWithBotPermission
                                        )
                                );
                        }
                } else {
                        $uid = User::idFromName( $this->target );
                        if ( $uid ) {
                                $condition['rev_user'] = $uid;
                                $index = 'user_timestamp';
                        } else {
                                $condition['rev_user_text'] = $this->target;
                                $index = 'usertext_timestamp';
                        }
                }

                if ( $this->deletedOnly ) {
                        $condition[] = 'rev_deleted != 0';
                }

                if ( $this->topOnly ) {
                        $condition[] = 'rev_id = page_latest';
                }

                if ( $this->newOnly ) {
                        $condition[] = 'rev_parent_id = 0';
                }

                return array( $tables, $index, $condition, $join_conds );
        }

        function getNamespaceCond() {
                if ( $this->namespace !== '' ) {
                        $selectedNS = $this->mDb->addQuotes( $this->namespace );
                        $eq_op = $this->nsInvert ? '!=' : '=';
                        $bool_op = $this->nsInvert ? 'AND' : 'OR';

                        if ( !$this->associated ) {
                                return array( "page_namespace $eq_op $selectedNS" );
                        }

                        $associatedNS = $this->mDb->addQuotes(
                                MWNamespace::getAssociated( $this->namespace )
                        );

                        return array(
                                "page_namespace $eq_op $selectedNS " .
                                        $bool_op .
                                        " page_namespace $eq_op $associatedNS"
                        );
                }

                return array();
        }

        function getIndexField() {
                return 'rev_timestamp';
        }

        function doBatchLookups() {
                # Do a link batch query
                $this->mResult->seek( 0 );
                $revIds = array();
                $batch = new LinkBatch();
                # Give some pointers to make (last) links
                foreach ( $this->mResult as $row ) {
                        if ( isset( $row->rev_parent_id ) && $row->rev_parent_id ) {
                                $revIds[] = $row->rev_parent_id;
                        }
                        if ( isset( $row->rev_id ) ) {
                                if ( $this->contribs === 'newbie' ) { // multiple users
                                        $batch->add( NS_USER, $row->user_name );
                                        $batch->add( NS_USER_TALK, $row->user_name );
                                }
                                $batch->add( $row->page_namespace, $row->page_title );
                        }
                }
                $this->mParentLens = Revision::getParentLengths( $this->mDbSecondary, $revIds );
                $batch->execute();
                $this->mResult->seek( 0 );
        }

        /**
         * @return string
         */
        function getStartBody() {
                return "<ul>\n";
        }

        /**
         * @return string
         */
        function getEndBody() {
                return "</ul>\n";
        }

        /**
         * Generates each row in the contributions list.
         *
         * Contributions which are marked "top" are currently on top of the history.
         * For these contributions, a [rollback] link is shown for users with roll-
         * back privileges. The rollback link restores the most recent version that
         * was not written by the target user.
         *
         * @todo This would probably look a lot nicer in a table.
         * @param object $row
         * @return string
         */
        function formatRow( $row ) {
                wfProfileIn( __METHOD__ );

                $ret = '';
                $classes = array();

                /*
                 * There may be more than just revision rows. To make sure that we'll only be processing
                 * revisions here, let's _try_ to build a revision out of our row (without displaying
                 * notices though) and then trying to grab data from the built object. If we succeed,
                 * we're definitely dealing with revision data and we may proceed, if not, we'll leave it
                 * to extensions to subscribe to the hook to parse the row.
                 */
                wfSuppressWarnings();
                try {
                        $rev = new Revision( $row );
                        $validRevision = (bool)$rev->getId();
                } catch ( MWException $e ) {
                        $validRevision = false;
                }
                wfRestoreWarnings();

                if ( $validRevision ) {
                        $classes = array();

                        $page = Title::newFromRow( $row );
                        $link = Linker::link(
                                $page,
                                htmlspecialchars( $page->getPrefixedText() ),
                                array( 'class' => 'mw-contributions-title' ),
                                $page->isRedirect() ? array( 'redirect' => 'no' ) : array()
                        );
                        # Mark current revisions
                        $topmarktext = '';
                        $user = $this->getUser();
                        if ( $row->rev_id == $row->page_latest ) {
                                $topmarktext .= '<span class="mw-uctop">' . $this->messages['uctop'] . '</span>';
                                # Add rollback link
                                if ( !$row->page_is_new && $page->quickUserCan( 'rollback', $user )
                                        && $page->quickUserCan( 'edit', $user )
                                ) {
                                        $this->preventClickjacking();
                                        $topmarktext .= ' ' . Linker::generateRollback( $rev, $this->getContext() );
                                }
                        }
                        # Is there a visible previous revision?
                        if ( $rev->userCan( Revision::DELETED_TEXT, $user ) && $rev->getParentId() !== 0 ) {
                                $difftext = Linker::linkKnown(
                                        $page,
                                        $this->messages['diff'],
                                        array(),
                                        array(
                                                'diff' => 'prev',
                                                'oldid' => $row->rev_id
                                        )
                                );
                        } else {
                                $difftext = $this->messages['diff'];
                        }
                        $histlink = Linker::linkKnown(
                                $page,
                                $this->messages['hist'],
                                array(),
                                array( 'action' => 'history' )
                        );

                        if ( $row->rev_parent_id === null ) {
                                // For some reason rev_parent_id isn't populated for this row.
                                // Its rumoured this is true on wikipedia for some revisions (bug 34922).
                                // Next best thing is to have the total number of bytes.
                                $chardiff = ' <span class="mw-changeslist-separator">. .</span> ';
                                $chardiff .= Linker::formatRevisionSize( $row->rev_len );
                                $chardiff .= ' <span class="mw-changeslist-separator">. .</span> ';
                        } else {
                                $parentLen = 0;
                                if ( isset( $this->mParentLens[$row->rev_parent_id] ) ) {
                                        $parentLen = $this->mParentLens[$row->rev_parent_id];
                                }

                                $chardiff = ' <span class="mw-changeslist-separator">. .</span> ';
                                $chardiff .= ChangesList::showCharacterDifference(
                                        $parentLen,
                                        $row->rev_len,
                                        $this->getContext()
                                );
                                $chardiff .= ' <span class="mw-changeslist-separator">. .</span> ';
                        }

                        $lang = $this->getLanguage();
                        $comment = $lang->getDirMark() . Linker::revComment( $rev, false, true );
                        $date = $lang->userTimeAndDate( $row->rev_timestamp, $user );
                        if ( $rev->userCan( Revision::DELETED_TEXT, $user ) ) {
                                $d = Linker::linkKnown(
                                        $page,
                                        htmlspecialchars( $date ),
                                        array( 'class' => 'mw-changeslist-date' ),
                                        array( 'oldid' => intval( $row->rev_id ) )
                                );
                        } else {
                                $d = htmlspecialchars( $date );
                        }
                        if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
                                $d = '<span class="history-deleted">' . $d . '</span>';
                        }

                        # Show user names for /newbies as there may be different users.
                        # Note that we already excluded rows with hidden user names.
                        if ( $this->contribs == 'newbie' ) {
                                $userlink = ' . . ' . $lang->getDirMark() . Linker::userLink( $rev->getUser(), $rev->getUserText() );
                                $userlink .= ' ' . $this->msg( 'parentheses' )->rawParams(
                                        Linker::userTalkLink( $rev->getUser(), $rev->getUserText() ) )->escaped() . ' ';
                        } else {
                                $userlink = '';
                        }

                        if ( $rev->getParentId() === 0 ) {
                                $nflag = ChangesList::flag( 'newpage' );
                        } else {
                                $nflag = '';
                        }

                        if ( $rev->isMinor() ) {
                                $mflag = ChangesList::flag( 'minor' );
                        } else {
                                $mflag = '';
                        }

                        $del = Linker::getRevDeleteLink( $user, $rev, $page );
                        if ( $del !== '' ) {
                                $del .= ' ';
                        }

                        $diffHistLinks = $this->msg( 'parentheses' )
                                ->rawParams( $difftext . $this->messages['pipe-separator'] . $histlink )
                                ->escaped();
                        $ret = "{$del}{$d} {$diffHistLinks}{$chardiff}{$nflag}{$mflag} ";
                        $ret .= "{$link}{$userlink} {$comment} {$topmarktext}";

                        # Denote if username is redacted for this edit
                        if ( $rev->isDeleted( Revision::DELETED_USER ) ) {
                                $ret .= " <strong>" .
                                        $this->msg( 'rev-deleted-user-contribs' )->escaped() .
                                        "</strong>";
                        }

                        # Tags, if any.
                        list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow(
                                $row->ts_tags,
                                'contributions'
                        );
                        $classes = array_merge( $classes, $newClasses );
                        $ret .= " $tagSummary";
                }

                // Let extensions add data
                wfRunHooks( 'ContributionsLineEnding', array( $this, &$ret, $row, &$classes ) );

                if ( $classes === array() && $ret === '' ) {
                        wfDebug( "Dropping Special:Contribution row that could not be formatted\n" );
                        $ret = "<!-- Could not format Special:Contribution row. -->\n";
                } else {
                        $ret = Html::rawElement( 'li', array( 'class' => $classes ), $ret ) . "\n";
                }

                wfProfileOut( __METHOD__ );

                return $ret;
        }

        /**
         * Overwrite Pager function and return a helpful comment
         * @return string
         */
        function getSqlComment() {
                if ( $this->namespace || $this->deletedOnly ) {
                        // potentially slow, see CR r58153
                        return 'contributions page filtered for namespace or RevisionDeleted edits';
                } else {
                        return 'contributions page unfiltered';
                }
        }

        protected function preventClickjacking() {
                $this->preventClickjacking = true;
        }

        /**
         * @return bool
         */
        public function getPreventClickjacking() {
                return $this->preventClickjacking;
        }
}