ZF-10560: log failed and unknown memcached client options

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@23143 44c647ce-9c0f-0410-b52a-842ac1e357ba

library/Zend/Cache/Backend/Libmemcached.php

@@ -128,10 +128,14 @@ class Zend_Cache_Backend_Libmemcached extends Zend_Cache_Backend implements Zend
                 $optConst = 'Memcached::OPT_' . strtoupper($name);
                 if (defined($optName)) {
                     $optId = constant($optConst);
+                } else {
+                    $this->_log("Unknown memcached client option '{$name}' ({$optConst})");
                 }
             }
             if ($optId) {
-                $this->_memcache->setOption($optId, $value);
+                if (!$this->_memcache->setOption($optId, $value)) {
+                    $this->_log("Setting memcached client option '{$optId}' failed");
+                }
             }
         }