Back-port #476 to the master branch

Author: lisachenko

Diff for: src/Proxy/Part/FunctionParameterList.php

@@ -39,13 +39,6 @@ public function __construct(ReflectionFunctionAbstract $functionLike, bool $useT
         foreach ($reflectionParameters as $reflectionParameter) {
             $defaultValue = null;
 
-            $isDefaultValueAvailable = $reflectionParameter->isDefaultValueAvailable();
-            if ($isDefaultValueAvailable) {
-                $defaultValue = new ValueGenerator($reflectionParameter->getDefaultValue());
-            } elseif ($reflectionParameter->isOptional() && !$reflectionParameter->isVariadic()) {
-                $defaultValue = new ValueGenerator(null);
-            }
-
             $parameterTypeName = null;
             if (!$useTypeWidening && $reflectionParameter->hasType()) {
                 $parameterReflectionType = $reflectionParameter->getType();
@@ -65,6 +58,19 @@ public function __construct(ReflectionFunctionAbstract $functionLike, bool $useT
             );
             $generatedParameter->setVariadic($reflectionParameter->isVariadic());
 
+            if (!$reflectionParameter->isVariadic()) {
+                $isDefaultValueAvailable = $reflectionParameter->isDefaultValueAvailable();
+                if ($isDefaultValueAvailable) {
+                    $defaultValue = new ValueGenerator($reflectionParameter->getDefaultValue());
+                } elseif ($reflectionParameter->isOptional()) {
+                    $defaultValue = new ValueGenerator(null);
+                }
+
+                if ($defaultValue instanceof ValueGenerator) {
+                    $generatedParameter->setDefaultValue($defaultValue);
+                }
+            }
+
             $this->generatedParameters[] = $generatedParameter;
         }
     }