Merge commit 'upstream/0.7.x' into 0.7.x

9 files changed, 425 insertions, 82 deletions

diff --git a/lib/action.php b/lib/action.php
index c4172ada1..ce92addf5 100644
--- a/lib/action.php
+++ b/lib/action.php
@@ -179,18 +179,27 @@ class Action extends HTMLOutputter // lawsuit
      */
     function showScripts()
     {
-        $this->element('script', array('type' => 'text/javascript',
-                                       'src' => common_path('js/jquery.min.js')),
-                       ' ');
-        $this->element('script', array('type' => 'text/javascript',
-                                       'src' => common_path('js/jquery.form.js')),
-                       ' ');
-        $this->element('script', array('type' => 'text/javascript',
-                                       'src' => common_path('js/xbImportNode.js')),
-                       ' ');
-        $this->element('script', array('type' => 'text/javascript',
-                                       'src' => common_path('js/util.js?version='.LACONICA_VERSION)),
-                       ' ');
+        if (Event::handle('StartShowScripts', array($this))) {
+            if (Event::handle('StartShowJQueryScripts', array($this))) {
+                $this->element('script', array('type' => 'text/javascript',
+                                               'src' => common_path('js/jquery.min.js')),
+                               ' ');
+                $this->element('script', array('type' => 'text/javascript',
+                                               'src' => common_path('js/jquery.form.js')),
+                               ' ');
+                Event::handle('EndShowJQueryScripts', array($this));
+            }
+            if (Event::handle('StartShowLaconicaScripts', array($this))) {
+                $this->element('script', array('type' => 'text/javascript',
+                                               'src' => common_path('js/xbImportNode.js')),
+                               ' ');
+                $this->element('script', array('type' => 'text/javascript',
+                                               'src' => common_path('js/util.js?version='.LACONICA_VERSION)),
+                               ' ');
+                Event::handle('EndShowLaconicaScripts', array($this));
+            }
+            Event::handle('EndShowScripts', array($this));
+        }
     }
 
     /**
@@ -312,42 +321,46 @@ class Action extends HTMLOutputter // lawsuit
      */
     function showPrimaryNav()
     {
+        $user = common_current_user();
+
         $this->elementStart('dl', array('id' => 'site_nav_global_primary'));
         $this->element('dt', null, _('Primary site navigation'));
         $this->elementStart('dd');
-        $user = common_current_user();
         $this->elementStart('ul', array('class' => 'nav'));
-        if ($user) {
-            $this->menuItem(common_local_url('all', array('nickname' => $user->nickname)),
-                            _('Home'), _('Personal profile and friends timeline'), false, 'nav_home');
-        }
-        $this->menuItem(common_local_url('peoplesearch'),
-                        _('Search'), _('Search for people or text'), false, 'nav_search');
-        if ($user) {
-            $this->menuItem(common_local_url('profilesettings'),
-                            _('Account'), _('Change your email, avatar, password, profile'), false, 'nav_account');
-
-            if (common_config('xmpp', 'enabled')) {
-                $this->menuItem(common_local_url('imsettings'),
-                            _('Connect'), _('Connect to IM, SMS, Twitter'), false, 'nav_connect');
-            } else {
-                $this->menuItem(common_local_url('smssettings'),
-                            _('Connect'), _('Connect to SMS, Twitter'), false, 'nav_connect');
+        if (Event::handle('StartPrimaryNav', array($this))) {
+            if ($user) {
+                $this->menuItem(common_local_url('all', array('nickname' => $user->nickname)),
+                                _('Home'), _('Personal profile and friends timeline'), false, 'nav_home');
             }
-            $this->menuItem(common_local_url('logout'),
-                            _('Logout'), _('Logout from the site'), false, 'nav_logout');
-        } else {
-            $this->menuItem(common_local_url('login'),
-                            _('Login'), _('Login to the site'), false, 'nav_login');
-            if (!common_config('site', 'closed')) {
-                $this->menuItem(common_local_url('register'),
-                                _('Register'), _('Create an account'), false, 'nav_register');
+            $this->menuItem(common_local_url('peoplesearch'),
+                            _('Search'), _('Search for people or text'), false, 'nav_search');
+            if ($user) {
+                $this->menuItem(common_local_url('profilesettings'),
+                                _('Account'), _('Change your email, avatar, password, profile'), false, 'nav_account');
+
+                if (common_config('xmpp', 'enabled')) {
+                    $this->menuItem(common_local_url('imsettings'),
+                                    _('Connect'), _('Connect to IM, SMS, Twitter'), false, 'nav_connect');
+                } else {
+                    $this->menuItem(common_local_url('smssettings'),
+                                    _('Connect'), _('Connect to SMS, Twitter'), false, 'nav_connect');
+                }
+                $this->menuItem(common_local_url('logout'),
+                                _('Logout'), _('Logout from the site'), false, 'nav_logout');
+            } else {
+                $this->menuItem(common_local_url('login'),
+                                _('Login'), _('Login to the site'), false, 'nav_login');
+                if (!common_config('site', 'closed')) {
+                    $this->menuItem(common_local_url('register'),
+                                    _('Register'), _('Create an account'), false, 'nav_register');
+                }
+                $this->menuItem(common_local_url('openidlogin'),
+                                _('OpenID'), _('Login with OpenID'), false, 'nav_openid');
             }
-            $this->menuItem(common_local_url('openidlogin'),
-                            _('OpenID'), _('Login with OpenID'), false, 'nav_openid');
+            $this->menuItem(common_local_url('doc', array('title' => 'help')),
+                            _('Help'), _('Help me!'), false, 'nav_help');
+            Event::handle('EndPrimaryNav', array($this));
         }
-        $this->menuItem(common_local_url('doc', array('title' => 'help')),
-                        _('Help'), _('Help me!'), false, 'nav_help');
         $this->elementEnd('ul');
         $this->elementEnd('dd');
         $this->elementEnd('dl');
@@ -511,12 +524,16 @@ class Action extends HTMLOutputter // lawsuit
      *
      * @return nothing
      */
+
     function showAside()
     {
         $this->elementStart('div', array('id' => 'aside_primary',
                                          'class' => 'aside'));
         $this->showExportData();
-        $this->showSections();
+        if (Event::handle('StartShowSections', array($this))) {
+            $this->showSections();
+            Event::handle('EndShowSections', array($this));
+        }
         $this->elementEnd('div');
     }
 
@@ -570,18 +587,21 @@ class Action extends HTMLOutputter // lawsuit
         $this->element('dt', null, _('Secondary site navigation'));
         $this->elementStart('dd', null);
         $this->elementStart('ul', array('class' => 'nav'));
-        $this->menuItem(common_local_url('doc', array('title' => 'help')),
-                        _('Help'));
-        $this->menuItem(common_local_url('doc', array('title' => 'about')),
-                        _('About'));
-        $this->menuItem(common_local_url('doc', array('title' => 'faq')),
-                        _('FAQ'));
-        $this->menuItem(common_local_url('doc', array('title' => 'privacy')),
-                        _('Privacy'));
-        $this->menuItem(common_local_url('doc', array('title' => 'source')),
-                        _('Source'));
-        $this->menuItem(common_local_url('doc', array('title' => 'contact')),
-                        _('Contact'));
+        if (Event::handle('StartSecondaryNav', array($this))) {
+            $this->menuItem(common_local_url('doc', array('title' => 'help')),
+                            _('Help'));
+            $this->menuItem(common_local_url('doc', array('title' => 'about')),
+                            _('About'));
+            $this->menuItem(common_local_url('doc', array('title' => 'faq')),
+                            _('FAQ'));
+            $this->menuItem(common_local_url('doc', array('title' => 'privacy')),
+                            _('Privacy'));
+            $this->menuItem(common_local_url('doc', array('title' => 'source')),
+                            _('Source'));
+            $this->menuItem(common_local_url('doc', array('title' => 'contact')),
+                            _('Contact'));
+            Event::handle('EndSecondaryNav', array($this));
+        }
         $this->elementEnd('ul');
         $this->elementEnd('dd');
         $this->elementEnd('dl');
@@ -789,11 +809,12 @@ class Action extends HTMLOutputter // lawsuit
      *
      * @return nothing
      */
+
     function serverError($msg, $code=500)
     {
         $action = $this->trimmed('action');
         common_debug("Server error '$code' on '$action': $msg", __FILE__);
-        common_server_error($msg, $code);
+        throw new ServerException($msg, $code);
     }
 
     /**
@@ -804,11 +825,12 @@ class Action extends HTMLOutputter // lawsuit
      *
      * @return nothing
      */
+
     function clientError($msg, $code=400)
     {
         $action = $this->trimmed('action');
         common_debug("User error '$code' on '$action': $msg", __FILE__);
-        common_user_error($msg, $code);
+        throw new ClientException($msg, $code);
     }
 
     /**
diff --git a/lib/clientexception.php b/lib/clientexception.php
new file mode 100644
index 000000000..3020d7f50
--- /dev/null
+++ b/lib/clientexception.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * class for a client exception (user error)
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Exception
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Class for client exceptions
+ *
+ * Subclass of PHP Exception for user errors.
+ *
+ * @category Exception
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ */
+
+class ClientException extends Exception
+{
+    public function __construct($message = null, $code = 400) {
+        parent::__construct($message, $code);
+    }
+
+    // custom string representation of object
+    public function __toString() {
+        return __CLASS__ . ": [{$this->code}]: {$this->message}\n";
+    }
+}
diff --git a/lib/common.php b/lib/common.php
index 5b4e3c40c..7bfd14c42 100644
--- a/lib/common.php
+++ b/lib/common.php
@@ -49,6 +49,12 @@ require_once('DB/DataObject/Cast.php'); # for dates
 
 require_once(INSTALLDIR.'/lib/language.php');
 
+// This gets included before the config file, so that admin code and plugins
+// can use it
+
+require_once(INSTALLDIR.'/lib/event.php');
+require_once(INSTALLDIR.'/lib/plugin.php');
+
 // try to figure out where we are
 
 $_server = array_key_exists('SERVER_NAME', $_SERVER) ?
@@ -177,6 +183,8 @@ foreach ($_config_files as $_config_file) {
     }
 }
 
+// XXX: how many of these could be auto-loaded on use?
+
 require_once('Validate.php');
 require_once('markdown.php');
 
@@ -188,6 +196,9 @@ require_once(INSTALLDIR.'/lib/subs.php');
 require_once(INSTALLDIR.'/lib/Shorturl_api.php');
 require_once(INSTALLDIR.'/lib/twitter.php');
 
+require_once(INSTALLDIR.'/lib/clientexception.php');
+require_once(INSTALLDIR.'/lib/serverexception.php');
+
 // XXX: other formats here
 
 define('NICKNAME_FMT', VALIDATE_NUM.VALIDATE_ALPHA_LOWER);
@@ -200,5 +211,12 @@ function __autoload($class)
         require_once(INSTALLDIR.'/classes/' . $class . '.php');
     } else if (file_exists(INSTALLDIR.'/lib/' . strtolower($class) . '.php')) {
         require_once(INSTALLDIR.'/lib/' . strtolower($class) . '.php');
+    } else if (mb_substr($class, -6) == 'Action' &&
+               file_exists(INSTALLDIR.'/actions/' . strtolower(mb_substr($class, 0, -6)) . '.php')) {
+        require_once(INSTALLDIR.'/actions/' . strtolower(mb_substr($class, 0, -6)) . '.php');
     }
 }
+
+// Give plugins a chance to initialize in a fully-prepared environment
+
+Event::handle('InitializePlugin');
diff --git a/lib/event.php b/lib/event.php
new file mode 100644
index 000000000..d815ae54b
--- /dev/null
+++ b/lib/event.php
@@ -0,0 +1,113 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * utilities for defining and running event handlers
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Event
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Class for events
+ *
+ * This "class" two static functions for managing events in the Laconica code.
+ *
+ * @category Event
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ *
+ * @todo     Define a system for using Event instances
+ */
+
+class Event {
+
+    /* Global array of hooks, mapping eventname => array of callables */
+
+    protected static $_handlers = array();
+
+    /**
+     * Add an event handler
+     *
+     * To run some code at a particular point in Laconica processing.
+     * Named events include receiving an XMPP message, adding a new notice,
+     * or showing part of an HTML page.
+     *
+     * The arguments to the handler vary by the event. Handlers can return
+     * two possible values: false means that the event has been replaced by
+     * the handler completely, and no default processing should be done.
+     * Non-false means successful handling, and that the default processing
+     * should succeed. (Note that this only makes sense for some events.)
+     *
+     * Handlers can also abort processing by throwing an exception; these will
+     * be caught by the closest code and displayed as errors.
+     *
+     * @param string   $name    Name of the event
+     * @param callable $handler Code to run
+     *
+     * @return void
+     */
+
+    public static function addHandler($name, $handler) {
+        if (array_key_exists($name, Event::$_handlers)) {
+            Event::$_handlers[$name][] = $handler;
+        } else {
+            Event::$_handlers[$name] = array($handler);
+        }
+    }
+
+    /**
+     * Handle an event
+     *
+     * Events are any point in the code that we want to expose for admins
+     * or third-party developers to use.
+     *
+     * We pass in an array of arguments (including references, for stuff
+     * that can be changed), and each assigned handler gets run with those
+     * arguments. Exceptions can be thrown to indicate an error.
+     *
+     * @param string $name Name of the event that's happening
+     * @param array  $args Arguments for handlers
+     *
+     * @return boolean flag saying whether to continue processing, based
+     *                 on results of handlers.
+     */
+
+    public static function handle($name, $args=array()) {
+        $result = null;
+        if (array_key_exists($name, Event::$_handlers)) {
+            foreach (Event::$_handlers[$name] as $handler) {
+                $result = call_user_func_array($handler, $args);
+                if ($result === false) {
+                    break;
+                }
+            }
+        }
+        return ($result !== false);
+    }
+}
diff --git a/lib/htmloutputter.php b/lib/htmloutputter.php
index 7780b1c19..e2319b1fd 100644
--- a/lib/htmloutputter.php
+++ b/lib/htmloutputter.php
@@ -255,7 +255,7 @@ class HTMLOutputter extends XMLOutputter
         foreach ($content as $value => $option) {
             if ($value == $selected) {
                 $this->element('option', array('value' => $value,
-                                               'selected' => $value),
+                                               'selected' => 'selected'),
                                $option);
             } else {
                 $this->element('option', array('value' => $value), $option);
diff --git a/lib/imagefile.php b/lib/imagefile.php
index ea24029a3..0c93b257e 100644
--- a/lib/imagefile.php
+++ b/lib/imagefile.php
@@ -68,17 +68,17 @@ class ImageFile
     static function fromUpload($param='upload')
     {
         switch ($_FILES[$param]['error']) {
-        case UPLOAD_ERR_OK: // success, jump out
+         case UPLOAD_ERR_OK: // success, jump out
             break;
-        case UPLOAD_ERR_INI_SIZE:
-        case UPLOAD_ERR_FORM_SIZE:
+         case UPLOAD_ERR_INI_SIZE:
+         case UPLOAD_ERR_FORM_SIZE:
             throw new Exception(sprintf(_('That file is too big. The maximum file size is %d.'), $this->maxFileSize()));
             return;
-        case UPLOAD_ERR_PARTIAL:
+         case UPLOAD_ERR_PARTIAL:
             @unlink($_FILES[$param]['tmp_name']);
             throw new Exception(_('Partial upload.'));
             return;
-        default:
+         default:
             throw new Exception(_('System error uploading file.'));
             return;
         }
@@ -112,19 +112,19 @@ class ImageFile
             throw new Exception(_('Lost our file.'));
             return;
         }
-        
+
         // Don't crop/scale if it isn't necessary
-        if ($size === $this->width 
-            && $size === $this->height 
-            && $x === 0 
-            && $y === 0 
+        if ($size === $this->width
+            && $size === $this->height
+            && $x === 0
+            && $y === 0
             && $w === $this->width
             && $h === $this->height) {
-            
+
             $outname = Avatar::filename($this->id,
-                                                image_type_to_extension($this->type),
-                                                $size,
-                                                common_timestamp());
+                                        image_type_to_extension($this->type),
+                                        $size,
+                                        common_timestamp());
             $outpath = Avatar::path($outname);
             @copy($this->filepath, $outpath);
             return $outname;
@@ -171,9 +171,9 @@ class ImageFile
         imagecopyresampled($image_dest, $image_src, 0, 0, $x, $y, $size, $size, $w, $h);
 
         $outname = Avatar::filename($this->id,
-                                          image_type_to_extension($this->type),
-                                          $size,
-                                          common_timestamp());
+                                    image_type_to_extension($this->type),
+                                    $size,
+                                    common_timestamp());
 
         $outpath = Avatar::path($outname);
 
@@ -191,7 +191,7 @@ class ImageFile
             throw new Exception(_('Unknown file type'));
             return;
         }
-        
+
         imagedestroy($image_src);
         imagedestroy($image_dest);
 
@@ -229,12 +229,12 @@ class ImageFile
         $num = substr($str, 0, -1);
 
         switch(strtoupper($unit)){
-            case 'G':
-                $num *= 1024;
-            case 'M':
-                $num *= 1024;
-            case 'K':
-                $num *= 1024;
+         case 'G':
+            $num *= 1024;
+         case 'M':
+            $num *= 1024;
+         case 'K':
+            $num *= 1024;
         }
 
         return $num;
diff --git a/lib/plugin.php b/lib/plugin.php
new file mode 100644
index 000000000..7b2436e54
--- /dev/null
+++ b/lib/plugin.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * Utility class for plugins
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Plugin
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Base class for plugins
+ *
+ * A base class for Laconica plugins. Mostly a light wrapper around
+ * the Event framework.
+ *
+ * Subclasses of Plugin will automatically handle an event if they define
+ * a method called "onEventName". (Well, OK -- only if they call parent::__construct()
+ * in their constructors.)
+ *
+ * They will also automatically handle the InitializePlugin and CleanupPlugin with the
+ * initialize() and cleanup() methods, respectively.
+ *
+ * @category Plugin
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ *
+ * @see      Event
+ */
+
+class Plugin
+{
+    function __construct()
+    {
+        Event::addHandler('InitializePlugin', array($this, 'initialize'));
+        Event::addHandler('CleanupPlugin', array($this, 'cleanup'));
+
+        foreach (get_class_methods($this) as $method) {
+            if (mb_substr($method, 0, 2) == 'on') {
+                Event::addHandler(mb_substr($method, 2), array($this, $method));
+            }
+        }
+    }
+
+    function initialize()
+    {
+        return true;
+    }
+
+    function cleanup()
+    {
+        return true;
+    }
+}
diff --git a/lib/serverexception.php b/lib/serverexception.php
new file mode 100644
index 000000000..b8ed6846e
--- /dev/null
+++ b/lib/serverexception.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * class for a server exception (user error)
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Exception
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Class for server exceptions
+ *
+ * Subclass of PHP Exception for server errors. The user typically can't fix these.
+ *
+ * @category Exception
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ */
+
+class ServerException extends Exception
+{
+    public function __construct($message = null, $code = 400) {
+        parent::__construct($message, $code);
+    }
+
+    public function __toString() {
+        return __CLASS__ . ": [{$this->code}]: {$this->message}\n";
+    }
+}
diff --git a/lib/util.php b/lib/util.php
index 5204693bc..be92f422f 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -481,7 +481,7 @@ function common_linkify($url) {
     }
     else $title = '';
 
-    return "<a href=\"$url\" $title class=\"extlink\">$display</a>";
+    return "<a href=\"$url\" $title rel=\"external\">$display</a>";
 }
 
 function common_longurl($short_url)