Empty output of extended template with block inside capture

[zdenekzahor]

Version: 2.8.1

Bug Description

(see https://forum.nette.org/cs/33497-latte-block-uvnitr-capture-zpusobi-bilou-stranku)

Steps To Reproduce

1. composer require latte/latte:^2.8

2. create file layout.latte:

   {include content}

3. create file default.latte:

   {extends @layout.latte}
   
   {capture $foo}
       {block bar}
           baz
       {/block}
   {/capture}
   
   {block content}
   content text
   

4. php -r 'require __DIR__ . "/vendor/autoload.php"; $engine = new Latte\Engine; $engine->render("default.latte");'

Expected Behavior

Exception or result: content text (?)