Changed statistics driver plugin manager to return non-shared instances;...

Changed statistics driver plugin manager to return non-shared instances; eliminated explicit cloning.

module/VuFind/src/VuFind/Statistics/AbstractBase.php

@@ -140,7 +140,7 @@ abstract class AbstractBase implements ServiceLocatorAwareInterface
                 // If we got this far, we want the current option!  Build the driver:
                 $loader = $this->getServiceLocator()
                     ->get('StatisticsDriverPluginManager');
-                $newDriver = clone($loader->get($setting[0]));
+                $newDriver = $loader->get($setting[0]);
 
                 // Set the name of the data source;  we use the special value
                 // "global" to represent global writer requests (the special null

module/VuFind/src/VuFind/Statistics/Driver/PluginManager.php

@@ -38,6 +38,21 @@ namespace VuFind\Statistics\Driver;
  */
 class PluginManager extends \VuFind\ServiceManager\AbstractPluginManager
 {
+    /**
+     * Constructor
+     *
+     * @param null|ConfigInterface $configuration Configuration settings (optional)
+     */
+    public function __construct(
+        \Zend\ServiceManager\ConfigInterface $configuration = null
+    ) {
+        parent::__construct($configuration);
+
+        // Stats drivers are not meant to be shared -- every time we retrieve one,
+        // we are building a brand new object.
+        $this->setShareByDefault(false);
+    }
+
     /**
      * Return the name of the base class or interface that plug-ins must conform
      * to.