Add support for Number grouping(commafy) based on CLDR number grouping patterns like...
[lhc/web/wiklou.git] / includes / Revision.php
index c6c8be8..243c9c0 100644 (file)
@@ -1,8 +1,4 @@
 <?php
-/**
- * @todo document
- * @file
- */
 
 /**
  * @todo document
@@ -12,19 +8,24 @@ class Revision {
        const DELETED_COMMENT = 2;
        const DELETED_USER = 4;
        const DELETED_RESTRICTED = 8;
+       // Convenience field
+       const SUPPRESSED_USER = 12;
+       // Audience options for Revision::getText()
+       const FOR_PUBLIC = 1;
+       const FOR_THIS_USER = 2;
+       const RAW = 3;
 
        /**
         * Load a page revision from a given revision ID number.
         * Returns null if no such revision can be found.
         *
-        * @param int $id
-        * @access public
-        * @static
+        * @param $id Integer
+        * @return Revision or null
         */
        public static function newFromId( $id ) {
                return Revision::newFromConds(
                        array( 'page_id=rev_page',
-                              'rev_id' => intval( $id ) ) );
+                                  'rev_id' => intval( $id ) ) );
        }
 
        /**
@@ -32,36 +33,116 @@ class Revision {
         * that's attached to a given title. If not attached
         * to that title, will return null.
         *
-        * @param Title $title
-        * @param int $id
-        * @return Revision
+        * @param $title Title
+        * @param $id Integer (optional)
+        * @return Revision or null
         */
        public static function newFromTitle( $title, $id = 0 ) {
-               if( $id ) {
-                       $matchId = intval( $id );
+               $conds = array(
+                       'page_namespace' => $title->getNamespace(),
+                       'page_title'     => $title->getDBkey()
+               );
+               if ( $id ) {
+                       // Use the specified ID
+                       $conds['rev_id'] = $id;
+               } elseif ( wfGetLB()->getServerCount() > 1 ) {
+                       // Get the latest revision ID from the master
+                       $dbw = wfGetDB( DB_MASTER );
+                       $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
+                       if ( $latest === false ) {
+                               return null; // page does not exist
+                       }
+                       $conds['rev_id'] = $latest;
                } else {
-                       $matchId = 'page_latest';
+                       // Use a join to get the latest revision
+                       $conds[] = 'rev_id=page_latest';
                }
-               return Revision::newFromConds(
-                       array( "rev_id=$matchId",
-                              'page_id=rev_page',
-                              'page_namespace' => $title->getNamespace(),
-                              'page_title'     => $title->getDBkey() ) );
+               $conds[] = 'page_id=rev_page';
+               return Revision::newFromConds( $conds );
+       }
+
+       /**
+        * Load either the current, or a specified, revision
+        * that's attached to a given page ID.
+        * Returns null if no such revision can be found.
+        *
+        * @param $revId Integer
+        * @param $pageId Integer (optional)
+        * @return Revision or null
+        */
+       public static function newFromPageId( $pageId, $revId = 0 ) {
+               $conds = array( 'page_id' => $pageId );
+               if ( $revId ) {
+                       $conds['rev_id'] = $revId;
+               } elseif ( wfGetLB()->getServerCount() > 1 ) {
+                       // Get the latest revision ID from the master
+                       $dbw = wfGetDB( DB_MASTER );
+                       $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
+                       if ( $latest === false ) {
+                               return null; // page does not exist
+                       }
+                       $conds['rev_id'] = $latest;
+               } else {
+                       $conds[] = 'rev_id = page_latest';
+               }
+               $conds[] = 'page_id=rev_page';
+               return Revision::newFromConds( $conds );
+       }
+
+       /**
+        * Make a fake revision object from an archive table row. This is queried
+        * for permissions or even inserted (as in Special:Undelete)
+        * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
+        *
+        * @param $row
+        * @param $overrides array
+        *
+        * @return Revision
+        */
+       public static function newFromArchiveRow( $row, $overrides = array() ) {
+               $attribs = $overrides + array(
+                       'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
+                       'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
+                       'comment'    => $row->ar_comment,
+                       'user'       => $row->ar_user,
+                       'user_text'  => $row->ar_user_text,
+                       'timestamp'  => $row->ar_timestamp,
+                       'minor_edit' => $row->ar_minor_edit,
+                       'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
+                       'deleted'    => $row->ar_deleted,
+                       'len'        => $row->ar_len);
+               if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
+                       // Pre-1.5 ar_text row
+                       $attribs['text'] = self::getRevisionText( $row, 'ar_' );
+                       if ( $attribs['text'] === false ) {
+                               throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
+                       }
+               }
+               return new self( $attribs );
+       }
+
+       /**
+        * @since 1.19
+        *
+        * @param $row
+        * @return Revision
+        */
+       public static function newFromRow( $row ) {
+               return new self( $row );
        }
 
        /**
         * Load a page revision from a given revision ID number.
         * Returns null if no such revision can be found.
         *
-        * @param Database $db
-        * @param int $id
-        * @access public
-        * @static
+        * @param $db DatabaseBase
+        * @param $id Integer
+        * @return Revision or null
         */
        public static function loadFromId( $db, $id ) {
                return Revision::loadFromConds( $db,
                        array( 'page_id=rev_page',
-                              'rev_id' => intval( $id ) ) );
+                                  'rev_id' => intval( $id ) ) );
        }
 
        /**
@@ -69,34 +150,54 @@ class Revision {
         * that's attached to a given page. If not attached
         * to that page, will return null.
         *
-        * @param Database $db
-        * @param int $pageid
-        * @param int $id
-        * @return Revision
-        * @access public
-        * @static
+        * @param $db DatabaseBase
+        * @param $pageid Integer
+        * @param $id Integer
+        * @return Revision or null
         */
        public static function loadFromPageId( $db, $pageid, $id = 0 ) {
-               $conds=array('page_id=rev_page','rev_page'=>intval( $pageid ), 'page_id'=>intval( $pageid ));
+               $conds = array( 'page_id=rev_page','rev_page' => intval( $pageid ), 'page_id'=>intval( $pageid ) );
                if( $id ) {
-                       $conds['rev_id']=intval($id);
+                       $conds['rev_id'] = intval( $id );
                } else {
-                       $conds[]='rev_id=page_latest';
+                       $conds[] = 'rev_id=page_latest';
                }
                return Revision::loadFromConds( $db, $conds );
        }
 
+       /**
+        * Stores the origin wiki of a revision in case it is a foreign wiki
+        */
+       function setWikiID( $wikiID ) {
+               $this->mWikiID = $wikiID;
+       }
+
+       /**
+        * Load the current revision of a given page of a foreign wiki.
+        * The WikiID is stored for further use, such as loadText() and getTimestampFromId()
+        */
+       public static function loadFromTitleForeignWiki( $wikiID, $title ) {
+               $dbr = wfGetDB( DB_SLAVE, array(), $wikiID );
+
+               $revision = self::loadFromTitle( $dbr, $title );
+
+               if( $revision ) {
+                       $revision->setWikiID( $wikiID );
+               }
+
+               return $revision;
+
+       }
+
        /**
         * Load either the current, or a specified, revision
         * that's attached to a given page. If not attached
         * to that page, will return null.
         *
-        * @param Database $db
-        * @param Title $title
-        * @param int $id
-        * @return Revision
-        * @access public
-        * @static
+        * @param $db DatabaseBase
+        * @param $title Title
+        * @param $id Integer
+        * @return Revision or null
         */
        public static function loadFromTitle( $db, $title, $id = 0 ) {
                if( $id ) {
@@ -107,9 +208,9 @@ class Revision {
                return Revision::loadFromConds(
                        $db,
                        array( "rev_id=$matchId",
-                              'page_id=rev_page',
-                              'page_namespace' => $title->getNamespace(),
-                              'page_title'     => $title->getDBkey() ) );
+                                  'page_id=rev_page',
+                                  'page_namespace' => $title->getNamespace(),
+                                  'page_title'     => $title->getDBkey() ) );
        }
 
        /**
@@ -117,34 +218,30 @@ class Revision {
         * WARNING: Timestamps may in some circumstances not be unique,
         * so this isn't the best key to use.
         *
-        * @param Database $db
-        * @param Title $title
-        * @param string $timestamp
-        * @return Revision
-        * @access public
-        * @static
+        * @param $db DatabaseBase
+        * @param $title Title
+        * @param $timestamp String
+        * @return Revision or null
         */
        public static function loadFromTimestamp( $db, $title, $timestamp ) {
                return Revision::loadFromConds(
                        $db,
                        array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
-                              'page_id=rev_page',
-                              'page_namespace' => $title->getNamespace(),
-                              'page_title'     => $title->getDBkey() ) );
+                                  'page_id=rev_page',
+                                  'page_namespace' => $title->getNamespace(),
+                                  'page_title'     => $title->getDBkey() ) );
        }
 
        /**
         * Given a set of conditions, fetch a revision.
         *
-        * @param array $conditions
-        * @return Revision
-        * @access private
-        * @static
+        * @param $conditions Array
+        * @return Revision or null
         */
-       private static function newFromConds( $conditions ) {
+       public static function newFromConds( $conditions ) {
                $db = wfGetDB( DB_SLAVE );
                $row = Revision::loadFromConds( $db, $conditions );
-               if( is_null( $row ) ) {
+               if( is_null( $row ) && wfGetLB()->getServerCount() > 1 ) {
                        $dbw = wfGetDB( DB_MASTER );
                        $row = Revision::loadFromConds( $dbw, $conditions );
                }
@@ -155,11 +252,9 @@ class Revision {
         * Given a set of conditions, fetch a revision from
         * the given database connection.
         *
-        * @param Database $db
-        * @param array $conditions
-        * @return Revision
-        * @access private
-        * @static
+        * @param $db DatabaseBase
+        * @param $conditions Array
+        * @return Revision or null
         */
        private static function loadFromConds( $db, $conditions ) {
                $res = Revision::fetchFromConds( $db, $conditions );
@@ -180,36 +275,16 @@ class Revision {
         * fetch all of a given page's revisions in turn.
         * Each row can be fed to the constructor to get objects.
         *
-        * @param Title $title
+        * @param $title Title
         * @return ResultWrapper
-        * @access public
-        * @static
-        */
-       public static function fetchAllRevisions( $title ) {
-               return Revision::fetchFromConds(
-                       wfGetDB( DB_SLAVE ),
-                       array( 'page_namespace' => $title->getNamespace(),
-                              'page_title'     => $title->getDBkey(),
-                              'page_id=rev_page' ) );
-       }
-
-       /**
-        * Return a wrapper for a series of database rows to
-        * fetch all of a given page's revisions in turn.
-        * Each row can be fed to the constructor to get objects.
-        *
-        * @param Title $title
-        * @return ResultWrapper
-        * @access public
-        * @static
         */
        public static function fetchRevision( $title ) {
                return Revision::fetchFromConds(
                        wfGetDB( DB_SLAVE ),
                        array( 'rev_id=page_latest',
-                              'page_namespace' => $title->getNamespace(),
-                              'page_title'     => $title->getDBkey(),
-                              'page_id=rev_page' ) );
+                                  'page_namespace' => $title->getNamespace(),
+                                  'page_title'     => $title->getDBkey(),
+                                  'page_id=rev_page' ) );
        }
 
        /**
@@ -217,32 +292,28 @@ class Revision {
         * which will return matching database rows with the
         * fields necessary to build Revision objects.
         *
-        * @param Database $db
-        * @param array $conditions
+        * @param $db DatabaseBase
+        * @param $conditions Array
         * @return ResultWrapper
-        * @access private
-        * @static
         */
        private static function fetchFromConds( $db, $conditions ) {
                $fields = self::selectFields();
                $fields[] = 'page_namespace';
                $fields[] = 'page_title';
                $fields[] = 'page_latest';
-               $res = $db->select(
+               return $db->select(
                        array( 'page', 'revision' ),
                        $fields,
                        $conditions,
-                       'Revision::fetchRow',
+                       __METHOD__,
                        array( 'LIMIT' => 1 ) );
-               $ret = $db->resultObject( $res );
-               return $ret;
        }
 
        /**
         * Return the list of revision fields that should be selected to create
         * a new revision.
         */
-       static function selectFields() {
+       public static function selectFields() {
                return array(
                        'rev_id',
                        'rev_page',
@@ -257,9 +328,9 @@ class Revision {
                        'rev_parent_id'
                );
        }
-       
+
        /**
-        * Return the list of text fields that should be selected to read the 
+        * Return the list of text fields that should be selected to read the
         * revision text
         */
        static function selectTextFields() {
@@ -268,6 +339,7 @@ class Revision {
                        'old_flags'
                );
        }
+
        /**
         * Return the list of page fields that should be selected from page table
         */
@@ -280,10 +352,12 @@ class Revision {
        }
 
        /**
-        * @param object $row
+        * Constructor
+        *
+        * @param $row Mixed: either a database row or an array
         * @access private
         */
-       function Revision( $row ) {
+       function __construct( $row ) {
                if( is_object( $row ) ) {
                        $this->mId        = intval( $row->rev_id );
                        $this->mPage      = intval( $row->rev_page );
@@ -295,20 +369,21 @@ class Revision {
                        $this->mTimestamp =         $row->rev_timestamp;
                        $this->mDeleted   = intval( $row->rev_deleted );
 
-                       if( !isset( $row->rev_parent_id ) )
+                       if( !isset( $row->rev_parent_id ) ) {
                                $this->mParentId = is_null($row->rev_parent_id) ? null : 0;
-                       else
+                       } else {
                                $this->mParentId  = intval( $row->rev_parent_id );
+                       }
 
-                       if( !isset( $row->rev_len ) || is_null( $row->rev_len ) )
+                       if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
                                $this->mSize = null;
-                       else
+                       } else {
                                $this->mSize = intval( $row->rev_len );
+                       }
 
                        if( isset( $row->page_latest ) ) {
-                               $this->mCurrent   = ( $row->rev_id == $row->page_latest );
-                               $this->mTitle     = Title::makeTitle( $row->page_namespace,
-                                                                     $row->page_title );
+                               $this->mCurrent = ( $row->rev_id == $row->page_latest );
+                               $this->mTitle = Title::newFromRow( $row );
                        } else {
                                $this->mCurrent = false;
                                $this->mTitle = null;
@@ -346,19 +421,18 @@ class Revision {
                        $this->mCurrent   = false;
                        # If we still have no len_size, see it we have the text to figure it out
                        if ( !$this->mSize )
-                               $this->mSize      = is_null($this->mText) ? null : strlen($this->mText);
+                               $this->mSize      = is_null( $this->mText ) ? null : strlen( $this->mText );
                } else {
                        throw new MWException( 'Revision constructor passed invalid row format.' );
                }
+               $this->mUnpatrolled = null;
+               $this->mWikiID = false;
        }
 
-       /**#@+
-        * @access public
-        */
-
        /**
         * Get revision ID
-        * @return int
+        *
+        * @return Integer
         */
        public function getId() {
                return $this->mId;
@@ -366,7 +440,8 @@ class Revision {
 
        /**
         * Get text row ID
-        * @return int
+        *
+        * @return Integer
         */
        public function getTextId() {
                return $this->mTextId;
@@ -374,7 +449,8 @@ class Revision {
 
        /**
         * Get parent revision ID (the original previous page revision)
-        * @return int
+        *
+        * @return Integer
         */
        public function getParentId() {
                return $this->mParentId;
@@ -382,7 +458,8 @@ class Revision {
 
        /**
         * Returns the length of the text in this revision, or null if unknown.
-        * @return int
+        *
+        * @return Integer
         */
        public function getSize() {
                return $this->mSize;
@@ -390,29 +467,31 @@ class Revision {
 
        /**
         * Returns the title of the page associated with this entry.
+        *
         * @return Title
         */
        public function getTitle() {
                if( isset( $this->mTitle ) ) {
                        return $this->mTitle;
                }
-               $dbr = wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
+
                $row = $dbr->selectRow(
                        array( 'page', 'revision' ),
                        array( 'page_namespace', 'page_title' ),
                        array( 'page_id=rev_page',
-                              'rev_id' => $this->mId ),
+                                  'rev_id' => $this->mId ),
                        'Revision::getTitle' );
                if( $row ) {
-                       $this->mTitle = Title::makeTitle( $row->page_namespace,
-                                                         $row->page_title );
+                       $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
                }
                return $this->mTitle;
        }
 
        /**
         * Set the title of the revision
-        * @param Title $title
+        *
+        * @param $title Title
         */
        public function setTitle( $title ) {
                $this->mTitle = $title;
@@ -420,18 +499,30 @@ class Revision {
 
        /**
         * Get the page ID
-        * @return int
+        *
+        * @return Integer
         */
        public function getPage() {
                return $this->mPage;
        }
 
        /**
-        * Fetch revision's user id if it's available to all users
-        * @return int
+        * Fetch revision's user id if it's available to the specified audience.
+        * If the specified audience does not have access to it, zero will be
+        * returned.
+        *
+        * @param $audience Integer: one of:
+        *      Revision::FOR_PUBLIC       to be displayed to all users
+        *      Revision::FOR_THIS_USER    to be displayed to $wgUser
+        *      Revision::RAW              get the ID regardless of permissions
+        *
+        *
+        * @return Integer
         */
-       public function getUser() {
-               if( $this->isDeleted( self::DELETED_USER ) ) {
+       public function getUser( $audience = self::FOR_PUBLIC ) {
+               if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
+                       return 0;
+               } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
                        return 0;
                } else {
                        return $this->mUser;
@@ -440,19 +531,30 @@ class Revision {
 
        /**
         * Fetch revision's user id without regard for the current user's permissions
-        * @return string
+        *
+        * @return String
         */
        public function getRawUser() {
                return $this->mUser;
        }
 
        /**
-        * Fetch revision's username if it's available to all users
+        * Fetch revision's username if it's available to the specified audience.
+        * If the specified audience does not have access to the username, an
+        * empty string will be returned.
+        *
+        * @param $audience Integer: one of:
+        *      Revision::FOR_PUBLIC       to be displayed to all users
+        *      Revision::FOR_THIS_USER    to be displayed to $wgUser
+        *      Revision::RAW              get the text regardless of permissions
+        *
         * @return string
         */
-       public function getUserText() {
-               if( $this->isDeleted( self::DELETED_USER ) ) {
-                       return "";
+       public function getUserText( $audience = self::FOR_PUBLIC ) {
+               if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
+                       return '';
+               } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
+                       return '';
                } else {
                        return $this->mUserText;
                }
@@ -460,19 +562,30 @@ class Revision {
 
        /**
         * Fetch revision's username without regard for view restrictions
-        * @return string
+        *
+        * @return String
         */
        public function getRawUserText() {
                return $this->mUserText;
        }
 
        /**
-        * Fetch revision comment if it's available to all users
-        * @return string
+        * Fetch revision comment if it's available to the specified audience.
+        * If the specified audience does not have access to the comment, an
+        * empty string will be returned.
+        *
+        * @param $audience Integer: one of:
+        *      Revision::FOR_PUBLIC       to be displayed to all users
+        *      Revision::FOR_THIS_USER    to be displayed to $wgUser
+        *      Revision::RAW              get the text regardless of permissions
+        *
+        * @return String
         */
-       function getComment() {
-               if( $this->isDeleted( self::DELETED_COMMENT ) ) {
-                       return "";
+       function getComment( $audience = self::FOR_PUBLIC ) {
+               if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
+                       return '';
+               } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT ) ) {
+                       return '';
                } else {
                        return $this->mComment;
                }
@@ -480,42 +593,96 @@ class Revision {
 
        /**
         * Fetch revision comment without regard for the current user's permissions
-        * @return string
+        *
+        * @return String
         */
        public function getRawComment() {
                return $this->mComment;
        }
 
        /**
-        * @return bool
+        * @return Boolean
         */
        public function isMinor() {
                return (bool)$this->mMinorEdit;
        }
 
        /**
-        * int $field one of DELETED_* bitfield constants
-        * @return bool
+        * @return Integer rcid of the unpatrolled row, zero if there isn't one
+        */
+       public function isUnpatrolled() {
+               if( $this->mUnpatrolled !== null ) {
+                       return $this->mUnpatrolled;
+               }
+               $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
+               $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
+                       'rc_id',
+                       array( // Add redundant user,timestamp condition so we can use the existing index
+                               'rc_user_text'  => $this->getRawUserText(),
+                               'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
+                               'rc_this_oldid' => $this->getId(),
+                               'rc_patrolled'  => 0
+                       ),
+                       __METHOD__
+               );
+               return (int)$this->mUnpatrolled;
+       }
+
+       /**
+        * @param $field int one of DELETED_* bitfield constants
+        *
+        * @return Boolean
         */
        public function isDeleted( $field ) {
-               return ($this->mDeleted & $field) == $field;
+               return ( $this->mDeleted & $field ) == $field;
        }
 
        /**
-        * Fetch revision text if it's available to all users
-        * @return string
+        * Get the deletion bitfield of the revision
+        *
+        * @return int
+        */
+       public function getVisibility() {
+               return (int)$this->mDeleted;
+       }
+
+       /**
+        * Fetch revision text if it's available to the specified audience.
+        * If the specified audience does not have the ability to view this
+        * revision, an empty string will be returned.
+        *
+        * @param $audience Integer: one of:
+        *      Revision::FOR_PUBLIC       to be displayed to all users
+        *      Revision::FOR_THIS_USER    to be displayed to $wgUser
+        *      Revision::RAW              get the text regardless of permissions
+        *
+        * @return String
         */
-       public function getText() {
-               if( $this->isDeleted( self::DELETED_TEXT ) ) {
-                       return "";
+       public function getText( $audience = self::FOR_PUBLIC ) {
+               if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
+                       return '';
+               } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT ) ) {
+                       return '';
                } else {
                        return $this->getRawText();
                }
        }
 
+       /**
+        * Alias for getText(Revision::FOR_THIS_USER)
+        *
+        * @deprecated since 1.17
+        * @return String
+        */
+       public function revText() {
+               wfDeprecated( __METHOD__ );
+               return $this->getText( self::FOR_THIS_USER );
+       }
+
        /**
         * Fetch revision text without regard for view restrictions
-        * @return string
+        *
+        * @return String
         */
        public function getRawText() {
                if( is_null( $this->mText ) ) {
@@ -526,26 +693,14 @@ class Revision {
        }
 
        /**
-        * Fetch revision text if it's available to THIS user
-        * @return string
-        */
-       public function revText() {
-               if( !$this->userCan( self::DELETED_TEXT ) ) {
-                       return "";
-               } else {
-                       return $this->getRawText();
-               }
-       }
-
-       /**
-        * @return string
+        * @return String
         */
        public function getTimestamp() {
-               return wfTimestamp(TS_MW, $this->mTimestamp);
+               return wfTimestamp( TS_MW, $this->mTimestamp );
        }
 
        /**
-        * @return bool
+        * @return Boolean
         */
        public function isCurrent() {
                return $this->mCurrent;
@@ -553,7 +708,8 @@ class Revision {
 
        /**
         * Get previous revision for this title
-        * @return Revision
+        *
+        * @return Revision or null
         */
        public function getPrevious() {
                if( $this->getTitle() ) {
@@ -566,7 +722,9 @@ class Revision {
        }
 
        /**
-        * @return Revision
+        * Get next revision for this title
+        *
+        * @return Revision or null
         */
        public function getNext() {
                if( $this->getTitle() ) {
@@ -581,11 +739,12 @@ class Revision {
        /**
         * Get previous revision Id for this page_id
         * This is used to populate rev_parent_id on save
-        * @param Database $db
-        * @return int
+        *
+        * @param $db DatabaseBase
+        * @return Integer
         */
        private function getPreviousRevisionId( $db ) {
-               if( is_null($this->mPage) ) {
+               if( is_null( $this->mPage ) ) {
                        return 0;
                }
                # Use page_latest if ID is not given
@@ -599,7 +758,7 @@ class Revision {
                                __METHOD__,
                                array( 'ORDER BY' => 'rev_id DESC' ) );
                }
-               return intval($prevId);
+               return intval( $prevId );
        }
 
        /**
@@ -607,9 +766,9 @@ class Revision {
          * $row is usually an object from wfFetchRow(), both the flags and the text
          * field must be included
          *
-         * @param integer $row Id of a row
-         * @param string $prefix table prefix (default 'old_')
-         * @return string $text|false the text requested
+         * @param $row Object: the text data
+         * @param $prefix String: table prefix (default 'old_')
+         * @return String: text the text requested or false on failure
          */
        public static function getRevisionText( $row, $prefix = 'old_' ) {
                wfProfileIn( __METHOD__ );
@@ -633,13 +792,13 @@ class Revision {
 
                # Use external methods for external objects, text in table is URL-only then
                if ( in_array( 'external', $flags ) ) {
-                       $url=$text;
-                       @list(/* $proto */,$path)=explode('://',$url,2);
-                       if ($path=="") {
+                       $url = $text;
+                       $parts = explode( '://', $url, 2 );
+                       if( count( $parts ) == 1 || $parts[1] == '' ) {
                                wfProfileOut( __METHOD__ );
                                return false;
                        }
-                       $text=ExternalStore::fetchFromURL($url);
+                       $text = ExternalStore::fetchFromURL( $url );
                }
 
                // If the text was fetched without an error, convert it
@@ -663,11 +822,15 @@ class Revision {
                        }
 
                        global $wgLegacyEncoding;
-                       if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
+                       if( $text !== false && $wgLegacyEncoding
+                               && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
+                       {
                                # Old revisions kept around in a legacy encoding?
                                # Upconvert on demand.
-                               global $wgInputEncoding, $wgContLang;
-                               $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
+                               # ("utf8" checked for compatibility with some broken
+                               #  conversion scripts 2008-12-30)
+                               global $wgContLang;
+                               $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
                        }
                }
                wfProfileOut( __METHOD__ );
@@ -681,8 +844,8 @@ class Revision {
         * data is compressed, and 'utf-8' if we're saving in UTF-8
         * mode.
         *
-        * @param mixed $text reference to a text
-        * @return string
+        * @param $text Mixed: reference to a text
+        * @return String
         */
        public static function compressRevisionText( &$text ) {
                global $wgCompressRevisions;
@@ -707,8 +870,8 @@ class Revision {
         * Insert a new revision into the database, returning the new revision ID
         * number on success and dies horribly on failure.
         *
-        * @param Database $dbw
-        * @return int
+        * @param $dbw DatabaseBase: (master connection)
+        * @return Integer
         */
        public function insertOn( $dbw ) {
                global $wgDefaultExternalStore;
@@ -721,7 +884,7 @@ class Revision {
                # Write to external storage if required
                if( $wgDefaultExternalStore ) {
                        // Store and get the URL
-                       $data = ExternalStore::randomInsert( $data );
+                       $data = ExternalStore::insertToDefault( $data );
                        if( !$data ) {
                                throw new MWException( "Unable to store text to external storage" );
                        }
@@ -733,7 +896,7 @@ class Revision {
 
                # Record the text (or external storage URL) to the text table
                if( !isset( $this->mTextId ) ) {
-                       $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
+                       $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
                        $dbw->insert( 'text',
                                array(
                                        'old_id'    => $old_id,
@@ -744,10 +907,12 @@ class Revision {
                        $this->mTextId = $dbw->insertId();
                }
 
+               if ( $this->mComment === null ) $this->mComment = "";
+
                # Record the edit in revisions
                $rev_id = isset( $this->mId )
                        ? $this->mId
-                       : $dbw->nextSequenceValue( 'rev_rev_id_val' );
+                       : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
                $dbw->insert( 'revision',
                        array(
                                'rev_id'         => $rev_id,
@@ -759,15 +924,16 @@ class Revision {
                                'rev_user_text'  => $this->mUserText,
                                'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
                                'rev_deleted'    => $this->mDeleted,
-                               'rev_len'            => $this->mSize,
-                               'rev_parent_id'  => $this->mParentId ? $this->mParentId : $this->getPreviousRevisionId( $dbw )
+                               'rev_len'        => $this->mSize,
+                               'rev_parent_id'  => is_null($this->mParentId) ?
+                                       $this->getPreviousRevisionId( $dbw ) : $this->mParentId
                        ), __METHOD__
                );
 
-               $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
-               
+               $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
+
                wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
-               
+
                wfProfileOut( __METHOD__ );
                return $this->mId;
        }
@@ -776,17 +942,23 @@ class Revision {
         * Lazy-load the revision's text.
         * Currently hardcoded to the 'text' table storage engine.
         *
-        * @return string
+        * @return String
         */
-       private function loadText() {
+       protected function loadText() {
                wfProfileIn( __METHOD__ );
 
                // Caching may be beneficial for massive use of external storage
                global $wgRevisionCacheExpiry, $wgMemc;
-               $key = wfMemcKey( 'revisiontext', 'textid', $this->getTextId() );
+               $textId = $this->getTextId();
+               if( isset( $this->mWikiID ) && $this->mWikiID !== false ) {
+                       $key = wfForeignMemcKey( $this->mWikiID, null, 'revisiontext', 'textid', $textId );
+               } else {
+               $key = wfMemcKey( 'revisiontext', 'textid', $textId );
+               }
                if( $wgRevisionCacheExpiry ) {
                        $text = $wgMemc->get( $key );
                        if( is_string( $text ) ) {
+                               wfDebug( __METHOD__ . ": got id $textId from cache\n" );
                                wfProfileOut( __METHOD__ );
                                return $text;
                        }
@@ -802,16 +974,16 @@ class Revision {
 
                if( !$row ) {
                        // Text data is immutable; check slaves first.
-                       $dbr = wfGetDB( DB_SLAVE );
+                       $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
                        $row = $dbr->selectRow( 'text',
                                array( 'old_text', 'old_flags' ),
                                array( 'old_id' => $this->getTextId() ),
                                __METHOD__ );
                }
 
-               if( !$row ) {
+               if( !$row && wfGetLB()->getServerCount() > 1 ) {
                        // Possible slave lag!
-                       $dbw = wfGetDB( DB_MASTER );
+                       $dbw = wfGetDB( DB_MASTER, array(), $this->mWikiID );
                        $row = $dbw->selectRow( 'text',
                                array( 'old_text', 'old_flags' ),
                                array( 'old_id' => $this->getTextId() ),
@@ -838,18 +1010,18 @@ class Revision {
         * Such revisions can for instance identify page rename
         * operations and other such meta-modifications.
         *
-        * @param Database $dbw
-        * @param int      $pageId ID number of the page to read from
-        * @param string   $summary
-        * @param bool     $minor
-        * @return Revision
+        * @param $dbw DatabaseBase
+        * @param $pageId Integer: ID number of the page to read from
+        * @param $summary String: revision's summary
+        * @param $minor Boolean: whether the revision should be considered as minor
+        * @return Revision|null on error
         */
        public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
                wfProfileIn( __METHOD__ );
 
                $current = $dbw->selectRow(
                        array( 'page', 'revision' ),
-                       array( 'page_latest', 'rev_text_id' ),
+                       array( 'page_latest', 'rev_text_id', 'rev_len' ),
                        array(
                                'page_id' => $pageId,
                                'page_latest=rev_id',
@@ -862,7 +1034,8 @@ class Revision {
                                'comment'    => $summary,
                                'minor_edit' => $minor,
                                'text_id'    => $current->rev_text_id,
-                               'parent_id'  => $current->page_latest
+                               'parent_id'  => $current->page_latest,
+                               'len'        => $current->rev_len
                                ) );
                } else {
                        $revision = null;
@@ -875,40 +1048,64 @@ class Revision {
        /**
         * Determine if the current user is allowed to view a particular
         * field of this revision, if it's marked as deleted.
-        * @param int $field one of self::DELETED_TEXT,
-        *                          self::DELETED_COMMENT,
-        *                          self::DELETED_USER
-        * @return bool
+        *
+        * @param $field Integer:one of self::DELETED_TEXT,
+        *                              self::DELETED_COMMENT,
+        *                              self::DELETED_USER
+        * @return Boolean
         */
        public function userCan( $field ) {
-               if( ( $this->mDeleted & $field ) == $field ) {
+               return self::userCanBitfield( $this->mDeleted, $field );
+       }
+
+       /**
+        * Determine if the current user is allowed to view a particular
+        * field of this revision, if it's marked as deleted. This is used
+        * by various classes to avoid duplication.
+        *
+        * @param $bitfield Integer: current field
+        * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
+        *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
+        *                               self::DELETED_USER = File::DELETED_USER
+        * @return Boolean
+        */
+       public static function userCanBitfield( $bitfield, $field ) {
+               if( $bitfield & $field ) { // aspect is deleted
                        global $wgUser;
-                       $permission = ( $this->mDeleted & self::DELETED_RESTRICTED ) == self::DELETED_RESTRICTED
-                               ? 'suppressrevision'
-                               : 'deleterevision';
-                       wfDebug( "Checking for $permission due to $field match on $this->mDeleted\n" );
+                       if ( $bitfield & self::DELETED_RESTRICTED ) {
+                               $permission = 'suppressrevision';
+                       } elseif ( $field & self::DELETED_TEXT ) {
+                               $permission = 'deletedtext';
+                       } else {
+                               $permission = 'deletedhistory';
+                       }
+                       wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
                        return $wgUser->isAllowed( $permission );
                } else {
                        return true;
                }
        }
 
-
        /**
         * Get rev_timestamp from rev_id, without loading the rest of the row
-        * @param integer $id
-        * @param integer $pageid, optional
+        *
+        * @param $title Title
+        * @param $id Integer
+        * @return String
         */
-       static function getTimestampFromId( $id, $pageId = 0 ) {
-               $dbr = wfGetDB( DB_SLAVE );
-               $conds = array( 'rev_id' => $id );
-               if( $pageId ) {
-                       $conds['rev_page'] = $pageId;
+       static function getTimestampFromId( $title, $id ) {
+               $wikiId = wfWikiID();
+               $dbr = wfGetDB( DB_SLAVE, array(), $wikiId );
+               // Casting fix for DB2
+               if ( $id == '' ) {
+                       $id = 0;
                }
+               $conds = array( 'rev_id' => $id );
+               $conds['rev_page'] = $title->getArticleId();
                $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
-               if ( $timestamp === false ) {
+               if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
                        # Not in slave, try master
-                       $dbw = wfGetDB( DB_MASTER );
+                       $dbw = wfGetDB( DB_MASTER, array(), $wikiId );
                        $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
                }
                return wfTimestamp( TS_MW, $timestamp );
@@ -916,8 +1113,10 @@ class Revision {
 
        /**
         * Get count of revisions per page...not very efficient
-        * @param Database $db
-        * @param int $id, page id
+        *
+        * @param $db DatabaseBase
+        * @param $id Integer: page id
+        * @return Integer
         */
        static function countByPageId( $db, $id ) {
                $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
@@ -930,8 +1129,10 @@ class Revision {
 
        /**
         * Get count of revisions per page...not very efficient
-        * @param Database $db
-        * @param Title $title
+        *
+        * @param $db DatabaseBase
+        * @param $title Title
+        * @return Integer
         */
        static function countByTitle( $db, $title ) {
                $id = $title->getArticleId();
@@ -941,11 +1142,3 @@ class Revision {
                return 0;
        }
 }
-
-/**
- * Aliases for backwards compatibility with 1.6
- */
-define( 'MW_REV_DELETED_TEXT', Revision::DELETED_TEXT );
-define( 'MW_REV_DELETED_COMMENT', Revision::DELETED_COMMENT );
-define( 'MW_REV_DELETED_USER', Revision::DELETED_USER );
-define( 'MW_REV_DELETED_RESTRICTED', Revision::DELETED_RESTRICTED );