bug symfony#21179 [TwigBundle] Fixing regression in TwigEngine exception handling (Bertalan Attila)

This PR was merged into the 2.7 branch.

Discussion
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[TwigBundle] Fixing regression in TwigEngine exception handling

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#21176
| License       | MIT

Fixing regression after symfony#20831 in TwigEngine exception handling.

Commits
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390cb33 Fixing regression in TwigEngine exception handling.

Author: nicolas-grekas

src/Symfony/Bundle/TwigBundle/TwigEngine.php

@@ -71,16 +71,12 @@ public function render($name, array $parameters = array())
         try {
             return parent::render($name, $parameters);
         } catch (\Twig_Error $e) {
-            if ($name instanceof TemplateReference) {
+            if ($name instanceof TemplateReference && !method_exists($e, 'setSourceContext')) {
                 try {
                     // try to get the real name of the template where the error occurred
                     $name = $e->getTemplateName();
                     $path = (string) $this->locator->locate($this->parser->parse($name));
-                    if (method_exists($e, 'setSourceContext')) {
-                        $e->setSourceContext(new \Twig_Source('', $name, $path));
-                    } else {
-                        $e->setTemplateName($path);
-                    }
+                    $e->setTemplateName($path);
                 } catch (\Exception $e2) {
                 }
             }