[Console] Ensure the console output is only detected as decorated when both stderr and stdout support colors

Author: Seldaek

src/Symfony/Component/Console/Output/ConsoleOutput.php

@@ -48,7 +48,12 @@ public function __construct($verbosity = self::VERBOSITY_NORMAL, $decorated = nu
     {
         parent::__construct($this->openOutputStream(), $verbosity, $decorated, $formatter);
 
+        $actualDecorated = $this->isDecorated();
         $this->stderr = new StreamOutput($this->openErrorStream(), $verbosity, $decorated, $this->getFormatter());
+
+        if (null === $decorated) {
+            $this->setDecorated($actualDecorated && $this->stderr->isDecorated());
+        }
     }
 
     /**