MAGETWO-30809: Compiled definitions can cause unexpected errors compared to runtime definitions

- Updated getParemeters logic to check if key is defined or not
- added unit test method

Author: Bibu Mathew

dev/tests/unit/testsuite/Magento/Framework/ObjectManager/Definition/Compiled/SerializedTest.php

@@ -31,4 +31,30 @@ public function testGetParametersWithUnpacking()
         $model = new \Magento\Framework\ObjectManager\Definition\Compiled\Serialized([$signatures, $definitions]);
         $this->assertEquals($checkString, $model->getParameters('wonderful'));
     }
+
+    public function testGetParametersWithUndefinedDefinition()
+    {
+        $objectManager = new \Magento\TestFramework\Helper\ObjectManager($this);
+        $undefinedDefinitionSignature = new \stdClass();
+        $className = 'undefinedDefinition';
+        $readerMock = $this->getMock(
+            '\Magento\Framework\Code\Reader\ClassReader',
+            ['getConstructor'],
+            [],
+            '',
+            false
+        );
+        $readerMock->expects($this->once())
+            ->method('getConstructor')
+            ->with($className)
+            ->willReturn($undefinedDefinitionSignature);
+        $model = $objectManager->getObject(
+            'Magento\Framework\ObjectManager\Definition\Compiled\Serialized',
+            [
+                'definitions' => [[], []],
+                'reader' => $readerMock
+            ]
+        );
+        $this->assertEquals($undefinedDefinitionSignature, $model->getParameters($className));
+    }
 }

lib/internal/Magento/Framework/ObjectManager/Definition/Compiled.php

@@ -23,6 +23,7 @@ abstract class Compiled implements \Magento\Framework\ObjectManager\DefinitionIn
 
     /**
      * @param array $definitions
+     * @param \Magento\Framework\Code\Reader\ClassReader $reader
      */
     public function __construct(array $definitions, \Magento\Framework\Code\Reader\ClassReader $reader = null)
     {
@@ -56,8 +57,8 @@ abstract protected function _unpack($signature);
      */
     public function getParameters($className)
     {
-        // if the definition isn't found in the list gathered from the compiled file using reflection to find it
-        if (!isset($this->_definitions[$className])) {
+        // if the definition isn't found in the list gathered from the compiled file then  using reflection to find it
+        if (!array_key_exists($className,$this->_definitions)) {
             return $this->reader->getConstructor($className);
         }