Reintroduced $this->configure. Assumed, configure may be called once

only this is important. Sorry.

Author: fhein

src/ServiceManager.php

@@ -21,7 +21,6 @@
 use Zend\ServiceManager\Exception\ServiceNotCreatedException;
 use Zend\ServiceManager\Exception\ServiceNotFoundException;
 
-use function \array_merge;
 use function \array_merge_recursive;
 use function \class_exists;
 use function \get_class;
@@ -133,6 +132,13 @@ class ServiceManager implements ServiceLocatorInterface
      */
     protected $sharedByDefault = true;
 
+    /**
+     * Service manager was already configured?
+     *
+     * @var bool
+     */
+    protected $configured = false;
+
     /**
      * Cached abstract factories from string.
      *
@@ -360,9 +366,8 @@ public function configure(array $config)
 
         if (isset($config['aliases'])) {
             $this->aliases = $config['aliases'] + $this->aliases;
-        }
-
-        if (! empty($this->aliases)) {
+            $this->mapAliasesToTargets();
+        } elseif (! $this->configured && ! empty($this->aliases)) {
             $this->mapAliasesToTargets();
         }
 
@@ -391,6 +396,8 @@ public function configure(array $config)
             $this->resolveInitializers($config['initializers']);
         }
 
+        $this->configured = true;
+
         return $this;
     }
 
@@ -782,7 +789,7 @@ private function createAliasesAndFactoriesForInvokables(array $invokables)
      */
     private function validateServiceNames(array $config)
     {
-        if ($this->allowOverride) {
+        if ($this->allowOverride || ! $this->configured) {
             return;
         }