diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b5f81a8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+sites/default/files/*
+sites/default/settings.php
\ No newline at end of file
diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index 2d85f6a..d29da83 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -99,7 +99,9 @@ public static function registerTwig(ContainerBuilder $container) {
         // This is saved / loaded via drupal_php_storage().
         // All files can be refreshed by clearing caches.
         // @todo ensure garbage collection of expired files.
-        'cache' => settings()->get('twig_cache', TRUE),
+        // When in the installer, twig_cache must be FALSE until we know the
+        // files folder is writable.
+        'cache' => drupal_installation_attempted() ? FALSE : settings()->get('twig_cache', TRUE),
         'base_template_class' => 'Drupal\Core\Template\TwigTemplate',
         // @todo Remove in followup issue
         // @see http://drupal.org/node/1712444.
diff --git a/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearchExecute.php b/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearchExecute.php
new file mode 100644
index 0000000..667c185
--- /dev/null
+++ b/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearchExecute.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace Drupal\node\Plugin\Search;
+
+use Drupal\search\SearchExecuteInterface;
+use Drupal\search\Annotation\SearchPagePlugin;
+
+/**
+ * Executes a keyword search aginst the search index.
+ *
+ * @SearchPagePlugin(
+ *   id = "node_search_execute",
+ *   title = "Content",
+ *   path = "node",
+ *   module = "node"
+ * )
+ */
+class NodeSearchExecute implements SearchExecuteInterface {
+  protected $keywords;
+
+  public function __construct($keywords, array $query_parameters, array $request_attributes) {
+    $this->keywords = $keywords;
+  }
+
+  public function isSearchExecutable() {
+    return (bool) $this->keywords;
+  }
+
+  public function execute() {
+    $results = array();
+    if (!$this->isSearchExecutable()) {
+      return $results;
+    }
+    $keys = $this->keywords;
+    // Build matching conditions
+    $query = db_select('search_index', 'i', array('target' => 'slave'))
+      ->extend('Drupal\search\SearchQuery')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
+    $query->join('node', 'n', 'n.nid = i.sid');
+    $query
+      ->condition('n.status', 1)
+      ->addTag('node_access')
+      ->searchExpression($keys, 'node');
+  
+    // Insert special keywords.
+    $query->setOption('type', 'n.type');
+    $query->setOption('langcode', 'n.langcode');
+    if ($query->setOption('term', 'ti.tid')) {
+      $query->join('taxonomy_index', 'ti', 'n.nid = ti.nid');
+    }
+    // Only continue if the first pass query matches.
+    if (!$query->executeFirstPass()) {
+      return array();
+    }
+  
+    // Add the ranking expressions.
+    _node_rankings($query);
+  
+    // Load results.
+    $find = $query
+      // Add the language code of the indexed item to the result of the query,
+      // since the node will be rendered using the respective language.
+      ->fields('i', array('langcode'))
+      ->limit(10)
+      ->execute();
+    foreach ($find as $item) {
+      // Render the node.
+      $node = node_load($item->sid);
+      $build = node_view($node, 'search_result', $item->langcode);
+      unset($build['#theme']);
+      $node->rendered = drupal_render($build);
+  
+      // Fetch comments for snippet.
+      $node->rendered .= ' ' . module_invoke('comment', 'node_update_index', $node, $item->langcode);
+  
+      $extra = module_invoke_all('node_search_result', $node, $item->langcode);
+  
+      $language = language_load($item->langcode);
+      $uri = $node->uri();
+      $results[] = array(
+        'link' => url($uri['path'], array_merge($uri['options'], array('absolute' => TRUE, 'language' => $language))),
+        'type' => check_plain(node_get_type_label($node)),
+        'title' => $node->label($item->langcode),
+        'user' => theme('username', array('account' => $node)),
+        'date' => $node->changed,
+        'node' => $node,
+        'extra' => $extra,
+        'score' => $item->calculated_score,
+        'snippet' => search_excerpt($keys, $node->rendered, $item->langcode),
+        'langcode' => $node->langcode,
+      );
+    }
+    return $results;
+  }
+}
\ No newline at end of file
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 1e1084e..215d5a1 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -1256,16 +1256,6 @@ function _node_rankings(SelectExtender $query) {
 }
 
 /**
- * Implements hook_search_info().
- */
-function node_search_info() {
-  return array(
-    'title' => 'Content',
-    'path' => 'node',
-  );
-}
-
-/**
  * Implements hook_search_access().
  */
 function node_search_access() {
@@ -1319,72 +1309,6 @@ function node_search_admin() {
 }
 
 /**
- * Implements hook_search_execute().
- */
-function node_search_execute($keys = NULL, $conditions = NULL) {
-  // Build matching conditions
-  $query = db_select('search_index', 'i', array('target' => 'slave'))
-    ->extend('Drupal\search\SearchQuery')
-    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
-  $query->join('node', 'n', 'n.nid = i.sid');
-  $query
-    ->condition('n.status', 1)
-    ->addTag('node_access')
-    ->searchExpression($keys, 'node');
-
-  // Insert special keywords.
-  $query->setOption('type', 'n.type');
-  $query->setOption('langcode', 'n.langcode');
-  if ($query->setOption('term', 'ti.tid')) {
-    $query->join('taxonomy_index', 'ti', 'n.nid = ti.nid');
-  }
-  // Only continue if the first pass query matches.
-  if (!$query->executeFirstPass()) {
-    return array();
-  }
-
-  // Add the ranking expressions.
-  _node_rankings($query);
-
-  // Load results.
-  $find = $query
-    // Add the language code of the indexed item to the result of the query,
-    // since the node will be rendered using the respective language.
-    ->fields('i', array('langcode'))
-    ->limit(10)
-    ->execute();
-  $results = array();
-  foreach ($find as $item) {
-    // Render the node.
-    $node = node_load($item->sid);
-    $build = node_view($node, 'search_result', $item->langcode);
-    unset($build['#theme']);
-    $node->rendered = drupal_render($build);
-
-    // Fetch comments for snippet.
-    $node->rendered .= ' ' . module_invoke('comment', 'node_update_index', $node, $item->langcode);
-
-    $extra = module_invoke_all('node_search_result', $node, $item->langcode);
-
-    $language = language_load($item->langcode);
-    $uri = $node->uri();
-    $results[] = array(
-      'link' => url($uri['path'], array_merge($uri['options'], array('absolute' => TRUE, 'language' => $language))),
-      'type' => check_plain(node_get_type_label($node)),
-      'title' => $node->label($item->langcode),
-      'user' => theme('username', array('account' => $node)),
-      'date' => $node->changed,
-      'node' => $node,
-      'extra' => $extra,
-      'score' => $item->calculated_score,
-      'snippet' => search_excerpt($keys, $node->rendered, $item->langcode),
-      'langcode' => $node->langcode,
-    );
-  }
-  return $results;
-}
-
-/**
  * Implements hook_ranking().
  */
 function node_ranking() {
diff --git a/core/modules/picture/picture.module b/core/modules/picture/picture.module
index 60d0f5b..7dbbaee 100644
--- a/core/modules/picture/picture.module
+++ b/core/modules/picture/picture.module
@@ -268,7 +268,7 @@ function theme_picture($variables) {
         );
       }
       else {
-        // Mutliple images, use srcset.
+        // Multiple images, use srcset.
         $srcset = array();
         foreach ($new_sources as $new_source) {
           $srcset[] = image_style_url($new_source['style_name'], $new_source['uri']) . ' ' . $new_source['#multiplier'];
diff --git a/core/modules/search/lib/Drupal/search/Annotation/SearchPagePlugin.php b/core/modules/search/lib/Drupal/search/Annotation/SearchPagePlugin.php
new file mode 100644
index 0000000..53fff9a
--- /dev/null
+++ b/core/modules/search/lib/Drupal/search/Annotation/SearchPagePlugin.php
@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\search\Annotation\SearchPagePlugin.
+ */
+
+namespace Drupal\search\Annotation;
+
+use Drupal\Component\Annotation\Plugin;
+
+/**
+ * Defines an Entity type annotation object.
+ *
+ * @Annotation
+ */
+class SearchPagePlugin extends Plugin {
+  /**
+   * The ID.
+   *
+   * @var string
+   */
+  public $id;
+
+  /**
+   * The name of the module providing the type.
+   *
+   * @var string
+   */
+  public $module;
+
+  /**
+   * The path of the search page.
+   *
+   * @var string
+   */
+  public $path;
+
+  /**
+   * The title for the search page tab.
+   *
+   * @var string
+   */
+  public $title;
+}
diff --git a/core/modules/search/lib/Drupal/search/SearchExecuteInterface.php b/core/modules/search/lib/Drupal/search/SearchExecuteInterface.php
new file mode 100644
index 0000000..be33f6c
--- /dev/null
+++ b/core/modules/search/lib/Drupal/search/SearchExecuteInterface.php
@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Modules\Search\SearchExecuteInterface.
+ */
+
+namespace Drupal\search;
+
+/**
+ * Defines a common interface for all SearchExecute objects.
+ */
+interface SearchExecuteInterface {
+  public function __construct($keywords, array $query_parameters, array $request_attributes);
+  public function isSearchExecutable();
+  public function execute();
+
+}
\ No newline at end of file
diff --git a/core/modules/search/lib/Drupal/search/SearchPagePluginManager.php b/core/modules/search/lib/Drupal/search/SearchPagePluginManager.php
new file mode 100644
index 0000000..37ebff4
--- /dev/null
+++ b/core/modules/search/lib/Drupal/search/SearchPagePluginManager.php
@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * Contains \Drupal\search\SearchPagePluginManager.
+ */
+
+namespace Drupal\search;
+
+use Drupal\Component\Plugin\Factory\DefaultFactory;
+use Drupal\Component\Plugin\PluginManagerBase;
+use Drupal\Core\Plugin\Discovery\AlterDecorator;
+use Drupal\Core\Plugin\Discovery\AnnotatedClassDiscovery;
+use Drupal\Core\Plugin\Discovery\CacheDecorator;
+
+/**
+ * SearchPage plugin manager.
+ */
+class SearchPagePluginManager extends PluginManagerBase {
+
+  /**
+   * Overrides \Drupal\Component\Plugin\PluginManagerBase::__construct().
+   *
+   * @param \Traversable $namespaces
+   *   An object that implements \Traversable which contains the root paths
+   *   keyed by the corresponding namespace to look for plugin implementations,
+   */
+  public function __construct(\Traversable $namespaces) {
+    $annotation_namespaces = array('Drupal\search\Annotation' => $namespaces['Drupal\search']);
+    $this->discovery = new AnnotatedClassDiscovery('Search', $namespaces, $annotation_namespaces, 'Drupal\search\Annotation\SearchPagePlugin');
+    $this->discovery = new AlterDecorator($this->discovery, 'search_info');
+    $this->discovery = new CacheDecorator($this->discovery, 'search');
+
+    $this->factory = new DefaultFactory($this->discovery);
+  }
+
+  /**
+   * Overrides \Drupal\Component\Plugin\PluginManagerBase::createInstance().
+   */
+  public function createInstance($plugin_id, array $configuration = array()) {
+    $plugin_definition = $this->discovery->getDefinition($plugin_id);
+    $plugin_class = DefaultFactory::getPluginClass($plugin_id, $plugin_definition);
+
+    // Normalize the data
+    $configuration + array(
+      'keywords' => '',
+      'query_parameters' => array(),
+      'request_attributes' => array(),
+    );
+    return new $plugin_class($configuration['keywords'], $configuration['query_parameters'], $configuration['request_attributes']);
+  }
+
+  /**
+   * Implements \Drupal\Core\PluginManagerInterface::getInstance().
+   *
+   * Finds an instance based on the module that owns the plugin
+   */
+  public function getInstance(array $options = array()) {
+    $module = $options['module'];
+    foreach ($this->getDefinitions() as $plugin_id => $definition) {
+      if ($definition['module'] == $module && !empty($options['configuration'])) {
+        // Return the instance of the searchExecutor where the annotation
+        // has mentioned it belongs to a certain module. Eg.: node
+        return $this->createInstance($plugin_id, $options['configuration']);
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/core/modules/search/search.module b/core/modules/search/search.module
index efaf031..f566e93 100644
--- a/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -151,6 +151,7 @@ function search_menu() {
   $items['search'] = array(
     'title' => 'Search',
     'page callback' => 'search_view',
+    'page arguments' => array(NULL, ''),
     'access callback' => 'search_is_active',
     'type' => MENU_SUGGESTED_ITEM,
     'file' => 'search.pages.inc',
@@ -177,28 +178,28 @@ function search_menu() {
   // system appears to be having two sets of tabs. See discussion on issue
   // http://drupal.org/node/245103 for details.
 
-  drupal_static_reset('search_get_info');
   $default_info = search_get_default_module_info();
   if ($default_info) {
-    foreach (search_get_info() as $module => $search_info) {
+    $search_definitions = Drupal::service('plugin.manager.search.page')->getDefinitions();
+    foreach ($search_definitions as $plugin_id => $search_info) {
       $path = 'search/' . $search_info['path'];
       $items[$path] = array(
         'title' => $search_info['title'],
         'page callback' => 'search_view',
-        'page arguments' => array($module, ''),
+        'page arguments' => array($plugin_id, ''),
         'access callback' => '_search_menu_access',
-        'access arguments' => array($module),
+        'access arguments' => array($search_info['module']),
         'type' => MENU_LOCAL_TASK,
         'file' => 'search.pages.inc',
-        'weight' => $module == $default_info['module'] ? -10 : 0,
+        'weight' => $search_info['module'] == $default_info['module'] ? -10 : 0,
       );
       $items["$path/%menu_tail"] = array(
         'title' => $search_info['title'],
         'load arguments' => array('%map', '%index'),
         'page callback' => 'search_view',
-        'page arguments' => array($module, 2),
+        'page arguments' => array($plugin_id, 2),
         'access callback' => '_search_menu_access',
-        'access arguments' => array($module),
+        'access arguments' => array($search_info['module']),
         // The default local task points to its parent, but this item points to
         // where it should so it should not be changed.
         'type' => MENU_LOCAL_TASK,
@@ -219,7 +220,7 @@ function search_menu() {
  */
 function search_is_active() {
   // This path cannot be accessed if there are no active modules.
-  return user_access('search content') && search_get_info();
+  return user_access('search content') && Drupal::service('plugin.manager.search.page')->getDefinitions();;
 }
 
 /**
@@ -231,30 +232,32 @@ function search_is_active() {
  *   have been set to active on the search settings page will be returned.
  *
  * @return
- *   Array of hook_search_info() return values, keyed by module name. The
+ *   Array of plugin.manager.search.page definitions, keyed by module name. The
  *   'title' and 'path' array elements will be set to defaults for each module
  *   if not supplied by hook_search_info(), and an additional array element of
  *   'module' will be added (set to the module name).
  */
 function search_get_info($all = FALSE) {
-  $search_hooks = &drupal_static(__FUNCTION__);
+  $search_info = &drupal_static(__FUNCTION__);
 
-  if (!isset($search_hooks)) {
-    foreach (module_implements('search_info') as $module) {
-      $search_hooks[$module] = call_user_func($module . '_search_info');
+  if (!isset($search_plugins)) {
+    $search_info = array();
+    $search_definitions = Drupal::service('plugin.manager.search.page')->getDefinitions();
+    foreach ($search_definitions as $plugin_id => $plugin) {
+      $module = $plugin['module'];
       // Use module name as the default value.
-      $search_hooks[$module] += array('title' => $module, 'path' => $module);
+      $search_info[$module] = array('title' => $module, 'path' => $module);
       // Include the module name itself in the array.
-      $search_hooks[$module]['module'] = $module;
+      $search_info[$module]['module'] = $module;
     }
   }
 
   if ($all) {
-    return $search_hooks;
+    return $search_info;
   }
 
   // Return only modules that are set to active in search settings.
-  return array_intersect_key($search_hooks, array_flip(config('search.settings')->get('active_modules')));
+  return array_intersect_key($search_info, array_flip(config('search.settings')->get('active_modules')));
 }
 
 /**
@@ -1071,9 +1074,8 @@ function search_box_form_submit($form, &$form_state) {
  *   Renderable array of search results. No return value if $keys are not
  *   supplied or if the given search module is not active.
  */
-function search_data($keys, $module, $conditions = NULL) {
-  if (module_hook($module, 'search_execute')) {
-    $results = module_invoke($module, 'search_execute', $keys, $conditions);
+function search_data(SearchExecuteInterface $plugin, $module) {
+    $results = $plugin->execute();
     if (module_hook($module, 'search_page')) {
       return module_invoke($module, 'search_page', $results);
     }
@@ -1084,7 +1086,6 @@ function search_data($keys, $module, $conditions = NULL) {
         '#module' => $module,
       );
     }
-  }
 }
 
 /**
diff --git a/core/modules/search/search.pages.inc b/core/modules/search/search.pages.inc
index eaae71a..3047f1f 100644
--- a/core/modules/search/search.pages.inc
+++ b/core/modules/search/search.pages.inc
@@ -13,7 +13,7 @@
  * @param $keys
  *   Keywords to use for the search.
  */
-function search_view($module = NULL, $keys = '') {
+function search_view($plugin_id = NULL, $keys = '') {
   $info = FALSE;
   $keys = trim($keys);
   // Also try to pull search keywords out of the $_REQUEST variable to
@@ -22,14 +22,7 @@ function search_view($module = NULL, $keys = '') {
     $keys = trim($_REQUEST['keys']);
   }
 
-  if (!empty($module)) {
-    $active_module_info = search_get_info();
-    if (isset($active_module_info[$module])) {
-      $info = $active_module_info[$module];
-    }
-  }
-
-  if (empty($info)) {
+  if (empty($plugin_id)) {
     // No path or invalid path: find the default module. Note that if there
     // are no enabled search modules, this function should never be called,
     // since hook_menu() would not have defined any search paths.
@@ -41,7 +34,13 @@ function search_view($module = NULL, $keys = '') {
     }
     drupal_goto($path);
   }
-
+  $request = Drupal::request();
+  $config = array(
+    'keywords' => $keys,
+    'query_parameters' => $request->query->all(),
+    'request_attributes' => $request->attributes->all(),
+  );
+  $plugin = Drupal::service('plugin.manager.search.page')->createInstance($plugin_id, $config);
   // Default results output is an empty string.
   $results = array('#markup' => '');
   // Process the search form. Note that if there is $_POST data,
@@ -50,18 +49,13 @@ function search_view($module = NULL, $keys = '') {
   // form submits with POST but redirects to GET. This way we can keep
   // the search query URL clean as a whistle.
   if (empty($_POST['form_id']) || $_POST['form_id'] != 'search_form') {
-    $conditions =  NULL;
-    if (isset($info['conditions_callback'])) {
-      // Build an optional array of more search conditions.
-      $conditions = call_user_func($info['conditions_callback'], $keys);
-    }
     // Only search if there are keywords or non-empty conditions.
-    if ($keys || !empty($conditions)) {
+    if ($plugin->isSearchExecutable()) {
       // Log the search keys.
       watchdog('search', 'Searched %type for %keys.', array('%keys' => $keys, '%type' => $info['title']), WATCHDOG_NOTICE, l(t('results'), 'search/' . $info['path'] . '/' . $keys));
 
       // Collect the search results.
-      $results = search_data($keys, $info['module'], $conditions);
+      $results = search_data($plugin, $info['module']);
     }
   }
   // The form may be altered based on whether the search was run.
diff --git a/core/modules/search/search.services.yml b/core/modules/search/search.services.yml
new file mode 100644
index 0000000..c80f7c7
--- /dev/null
+++ b/core/modules/search/search.services.yml
@@ -0,0 +1,4 @@
+services:
+  plugin.manager.search.page:
+    class: Drupal\search\SearchPagePluginManager
+    arguments: ['@container.namespaces']
\ No newline at end of file
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index cbf9f44..ce1b39b 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1243,6 +1243,7 @@ function system_library_info() {
       array('system', 'jquery'),
       array('system', 'drupal'),
       array('system', 'drupalSettings'),
+      array('system', 'drupal.ajax'),
       array('system', 'drupal.progress'),
       array('system', 'jquery.once'),
     ),
diff --git a/core/modules/user/lib/Drupal/user/Plugin/Search/UserSearchExecute.php b/core/modules/user/lib/Drupal/user/Plugin/Search/UserSearchExecute.php
new file mode 100644
index 0000000..d39fd75
--- /dev/null
+++ b/core/modules/user/lib/Drupal/user/Plugin/Search/UserSearchExecute.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Drupal\user\Plugin\Search;
+
+use Drupal\search\SearchExecuteInterface;
+use Drupal\search\Annotation\SearchPagePlugin;
+
+/**
+ * Executes a keyword search aginst the search index.
+ *
+ * @SearchPagePlugin(
+ *   id = "user_search_execute",
+ *   title = "Users",
+ *   path = "user",
+ *   module = "user"
+ * )
+ */
+class UserSearchExecute implements SearchExecuteInterface {
+  protected $keywords;
+
+  public function __construct($keywords, array $query_parameters, array $request_attributes) {
+    $this->keywords = $keywords;
+  }
+
+  public function isSearchExecutable() {
+    return (bool) $this->keywords;
+  }
+
+  public function execute() {
+    $results = array();
+    if (!$this->isSearchExecutable()) {
+      return $results;
+    }
+    $keys = $this->keywords;
+    $find = array();
+    // Replace wildcards with MySQL/PostgreSQL wildcards.
+    $keys = preg_replace('!\*+!', '%', $keys);
+    $query = db_select('users')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
+    $query->fields('users', array('uid'));
+    if (user_access('administer users')) {
+      // Administrators can also search in the otherwise private email field, and
+      // they don't need to be restricted to only active users.
+      $query->fields('users', array('mail'));
+      $query->condition(db_or()->
+        condition('name', '%' . db_like($keys) . '%', 'LIKE')->
+        condition('mail', '%' . db_like($keys) . '%', 'LIKE'));
+    }
+    else {
+      // Regular users can only search via usernames, and we do not show them
+      // blocked accounts.
+      $query->condition('name', '%' . db_like($keys) . '%', 'LIKE')
+        ->condition('status', 1);
+    }
+    $uids = $query
+      ->limit(15)
+      ->execute()
+      ->fetchCol();
+    $accounts = user_load_multiple($uids);
+  
+    foreach ($accounts as $account) {
+      $result = array(
+        'title' => user_format_name($account),
+        'link' => url('user/' . $account->uid, array('absolute' => TRUE)),
+      );
+      if (user_access('administer users')) {
+        $result['title'] .= ' (' . $account->mail . ')';
+      }
+      $results[] = $result;
+    }
+
+    return $results;
+  }
+}
\ No newline at end of file
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 0b884fa..81e7668 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -538,15 +538,6 @@ function user_permission() {
 }
 
 /**
- * Implements hook_search_info().
- */
-function user_search_info() {
-  return array(
-    'title' => 'Users',
-  );
-}
-
-/**
  * Implements hook_search_access().
  */
 function user_search_access() {
@@ -554,51 +545,6 @@ function user_search_access() {
 }
 
 /**
- * Implements hook_search_execute().
- */
-function user_search_execute($keys = NULL, $conditions = NULL) {
-  $find = array();
-  // Replace wildcards with MySQL/PostgreSQL wildcards.
-  $keys = preg_replace('!\*+!', '%', $keys);
-  $query = db_select('users')
-    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
-  $query->fields('users', array('uid'));
-  if (user_access('administer users')) {
-    // Administrators can also search in the otherwise private email field, and
-    // they don't need to be restricted to only active users.
-    $query->fields('users', array('mail'));
-    $query->condition(db_or()->
-      condition('name', '%' . db_like($keys) . '%', 'LIKE')->
-      condition('mail', '%' . db_like($keys) . '%', 'LIKE'));
-  }
-  else {
-    // Regular users can only search via usernames, and we do not show them
-    // blocked accounts.
-    $query->condition('name', '%' . db_like($keys) . '%', 'LIKE')
-      ->condition('status', 1);
-  }
-  $uids = $query
-    ->limit(15)
-    ->execute()
-    ->fetchCol();
-  $accounts = user_load_multiple($uids);
-
-  $results = array();
-  foreach ($accounts as $account) {
-    $result = array(
-      'title' => user_format_name($account),
-      'link' => url('user/' . $account->uid, array('absolute' => TRUE)),
-    );
-    if (user_access('administer users')) {
-      $result['title'] .= ' (' . $account->mail . ')';
-    }
-    $results[] = $result;
-  }
-
-  return $results;
-}
-
-/**
  * Implements hook_user_view().
  */
 function user_user_view(User $account, EntityDisplay $display) {