BackendCombined: Add option to configure GAL backend directly

Other methods currently don't work for BackendSearchLDAP:

• Configuring SEARCH_PROVIDER globally will push all search towards it
• Adding BackendSearchLDAP as a backend won't do anything unless it is also added to folderbackend
• BackendSearchLDAP doesn't implement Logon, so can't be used as folderbackend

src/backend/combined/combined.php

@@ -37,6 +37,7 @@ require_once("backend/combined/config.php");
 class BackendCombined extends Backend implements ISearchProvider {
     public $config;
     public $backends;
+    public $galbackend = NULL;
     private $activeBackend;
     private $activeBackendID;
     private $numberChangesSink;
@@ -50,12 +51,15 @@ class BackendCombined extends Backend implements ISearchProvider {
     public function __construct() {
         parent::__construct();
         $this->config = BackendCombinedConfig::GetBackendCombinedConfig();
-
         $backend_values = array_unique(array_values($this->config['folderbackend']));
         foreach ($backend_values as $i) {
             ZPush::IncludeBackend($this->config['backends'][$i]['name']);
             $this->backends[$i] = new $this->config['backends'][$i]['name']();
         }
+        if(array_key_exists('galbackend', $this->config)) {
+            ZPush::IncludeBackend($this->config['galbackend']);
+            $this->galbackend = new $this->config['galbackend']();
+        }
         ZLog::Write(LOGLEVEL_DEBUG, sprintf("Combined %d backends loaded.", count($this->backends)));
     }
 
@@ -558,6 +562,9 @@ class BackendCombined extends Backend implements ISearchProvider {
      */
     public function SupportsType($searchtype) {
         ZLog::Write(LOGLEVEL_DEBUG, sprintf("Combined->SupportsType('%s')", $searchtype));
+        if ($searchtype == ISearchProvider::SEARCH_GAL && !is_null($this->getGALBackendImpl())) {
+            return true;
+        }
         $i = $this->getSearchBackend($searchtype);
 
         return $i !== false;
@@ -577,11 +584,17 @@ class BackendCombined extends Backend implements ISearchProvider {
      */
     public function GetGALSearchResults($searchquery, $searchrange, $searchpicture) {
         ZLog::Write(LOGLEVEL_DEBUG, "Combined->GetGALSearchResults()");
-        $i = $this->getSearchBackend(ISearchProvider::SEARCH_GAL);
+        $galbackend = $this->getGALBackendImpl();
+        if (is_null($galbackend)) {
+            $i = $this->getSearchBackend(ISearchProvider::SEARCH_GAL);
+            if ($i !== false) {
+                $galbackend = $this->backends[$i];
+            }
+        }
 
         $result = false;
-        if ($i !== false) {
-            $result = $this->backends[$i]->GetGALSearchResults($searchquery, $searchrange, $searchpicture);
+        if (!is_null($galbackend)) {
+            $result = $galbackend->GetGALSearchResults($searchquery, $searchrange, $searchpicture);
         }
 
         return $result;
@@ -646,6 +659,22 @@ class BackendCombined extends Backend implements ISearchProvider {
     }
 
 
+    /**
+     * Check for a dedicated GAL backend
+     *
+     * @access private
+     * @return ISearchProvider
+     */
+    private function getGALBackendImpl() {
+        if ((!is_null($this->galbackend)) &&
+                ($this->galbackend instanceof ISearchProvider) &&
+                ($this->galbackend->SupportsType(ISearchProvider::SEARCH_GAL))) {
+            return $this->galbackend;
+        }
+        return NULL;
+    }
+
+
     /**
      * Returns the first backend that support a search type
      *