Merge branch '3.4' into 4.4

* 3.4:
  [Config] dont catch instances of Error

Author: nicolas-grekas

Resource/ClassExistenceResource.php

@@ -94,6 +94,8 @@ public function isFresh($timestamp)
                 }
             } catch (\Throwable $e) {
                 $exists[1] = $e->getMessage();
+
+                throw $e;
             } finally {
                 self::$autoloadedClass = $autoloadedClass;
                 if (!--self::$autoloadLevel) {

Tests/Fixtures/ParseError.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Symfony\Component\Config\Tests\Fixtures;
+
+class ParseError
+{
+// missing closing bracket

Tests/Resource/ClassExistenceResourceTest.php

@@ -15,6 +15,7 @@
 use Symfony\Component\Config\Resource\ClassExistenceResource;
 use Symfony\Component\Config\Tests\Fixtures\BadFileName;
 use Symfony\Component\Config\Tests\Fixtures\BadParent;
+use Symfony\Component\Config\Tests\Fixtures\ParseError;
 use Symfony\Component\Config\Tests\Fixtures\Resource\ConditionalClass;
 
 class ClassExistenceResourceTest extends TestCase
@@ -115,4 +116,12 @@ public function testConditionalClass()
 
         $this->assertFalse($res->isFresh(0));
     }
+
+    public function testParseError()
+    {
+        $this->expectException('ParseError');
+
+        $res = new ClassExistenceResource(ParseError::class, false);
+        $res->isFresh(0);
+    }
 }