Revert "bug #17052 [2.7] Fixed flatten exception recursion with errors (GrahamCampbell)"

This reverts commit af3f4eaa2b37bca77274b670e96a695f3e46c4e5, reversing
changes made to 021ab8a7b35cac053442124e04cd87e2e1ef43cd.

Exception/FlattenException.php

@@ -94,13 +94,8 @@ class FlattenException extends LegacyFlattenException
         $e->setClass(get_class($exception));
         $e->setFile($exception->getFile());
         $e->setLine($exception->getLine());
-
-        $previous = $exception->getPrevious();
-
-        if ($previous instanceof \Exception) {
-            $e->setPrevious(static::create($previous));
-        } elseif ($previous instanceof \Throwable) {
-            $e->setPrevious(static::create(new FatalThrowableError($previous)));
+        if ($exception->getPrevious()) {
+            $e->setPrevious(static::create($exception->getPrevious()));
         }
 
         return $e;

Tests/Exception/FlattenExceptionTest.php

@@ -131,20 +131,6 @@ class FlattenExceptionTest extends \PHPUnit_Framework_TestCase
         $this->assertSame(array($flattened2), $flattened->getAllPrevious());
     }
 
-    /**
-     * @requires PHP 7.0
-     */
-    public function testPreviousError()
-    {
-        $exception = new \Exception('test', 123, new \ParseError('Oh noes!', 42));
-
-        $flattened = FlattenException::create($exception)->getPrevious();
-
-        $this->assertEquals($flattened->getMessage(), 'Parse error: Oh noes!', 'The message is copied from the original exception.');
-        $this->assertEquals($flattened->getCode(), 42, 'The code is copied from the original exception.');
-        $this->assertEquals($flattened->getClass(), 'Symfony\Component\Debug\Exception\FatalThrowableError', 'The class is set to the class of the original exception');
-    }
-
     /**
      * @dataProvider flattenDataProvider
      */