PrefetchCache: respect CustomVar rendering type

fixes #1257

doc/82-Changelog.md

@@ -23,6 +23,16 @@ before switching to a new version.
   however allowed to store invalid single Service Objects with no Host. This is
   now illegal, as it never makes any sense
 
+1.4.2
+-----
+### Fixed issues
+* You can find issues and feature requests related to this release on our
+  [roadmap](https://github.com/Icinga/icingaweb2-module-director/milestone/13?closed=1)
+
+### Configuration rendering
+* FIX: Caching had an influence on context-specific Custom Variable rendering
+  when those variables contained macros (#1257)
+
 1.4.1
 -----
 ### Fixed issues

library/Director/Db/Cache/PrefetchCache.php

@@ -92,6 +92,7 @@ class PrefetchCache
         if (null === $checksum) {
             return $var->toConfigString($renderExpressions);
         } else {
+            $checksum .= (int) $renderExpressions;
             if (! array_key_exists($checksum, $this->renderedVars)) {
                 $this->renderedVars[$checksum] = $var->toConfigString($renderExpressions);
             }
@@ -100,6 +101,10 @@ class PrefetchCache
         }
     }
 
+    /**
+     * @param IcingaObject $object
+     * @return CustomVariableCache
+     */
     protected function varsCache(IcingaObject $object)
     {
         $key = $object->getShortTableName();