IcingaService: single objects w/o host must fail

fixes #1236

doc/82-Changelog.md

@@ -18,6 +18,11 @@ before switching to a new version.
 * FEATURE: Admins have now access to JSON download links in many places
 * FEATURE: Users equipped with related permissions can toggle "Show SQL" in the GUI
 
+### Import and Sync
+* FIX: Sync is very powerful and allows for actions not available in the GUI. It
+  however allowed to store invalid single Service Objects with no Host. This is
+  now illegal, as it never makes any sense
+
 1.4.1
 -----
 ### Fixed issues

library/Director/Objects/IcingaService.php

@@ -3,6 +3,7 @@
 namespace Icinga\Module\Director\Objects;
 
 use Icinga\Data\Filter\Filter;
+use Icinga\Exception\IcingaException;
 use Icinga\Exception\ProgrammingError;
 use Icinga\Module\Director\Db;
 use Icinga\Module\Director\Data\PropertiesFilter;
@@ -516,4 +517,17 @@ class IcingaService extends IcingaObject
 
         return $properties;
     }
+
+    protected function beforeStore()
+    {
+        parent::beforeStore();
+        if ($this->isObject()
+            && $this->get('service_set_id') === null
+            && $this->get('host_id') === null
+        ) {
+            throw new IcingaException(
+                'Cannot store a Service object without a related host'
+            );
+        }
+    }
 }