Do not render exceptions in streamed download

Author: JosephSilber

src/Illuminate/Foundation/Exceptions/Handler.php

@@ -369,6 +369,13 @@ protected function prepareException(Throwable $e)
      */
     protected function mapException(Throwable $e)
     {
+        if (
+            method_exists($e, 'getInnerException') &&
+            ($inner = $e->getInnerException()) instanceof Throwable
+        ) {
+            return $inner;
+        }
+
         foreach ($this->exceptionMap as $class => $mapper) {
             if (is_a($e, $class)) {
                 return $mapper($e);

src/Illuminate/Routing/Exceptions/StreamedResponseException.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Illuminate\Routing\Exceptions;
+
+use Illuminate\Http\Response;
+use RuntimeException;
+use Throwable;
+
+class StreamedResponseException extends RuntimeException
+{
+    /**
+     * The actual exception thrown during the stream.
+     *
+     * @var \Throwable
+     */
+    public $originalException;
+
+    /**
+     * Create a new exception instance.
+     *
+     * @param  \Throwable  $originalException
+     * @return void
+     */
+    public function __construct(Throwable $originalException)
+    {
+        $this->originalException = $originalException;
+
+        parent::__construct($originalException->message);
+    }
+
+    /**
+     * Render the exception.
+     *
+     * @return \Illuminate\Http\Response
+     */
+    public function render()
+    {
+        // Since we are in the process of streaming a file download,
+        // we don't actually want it to render anything into the
+        // file being downloaded. We return an empty response.
+        return new Response('');
+    }
+
+    /**
+     * Get the actual exception thrown during the stream.
+     *
+     * @return \Throwable
+     */
+    public function getInnerException()
+    {
+        return $this->originalException;
+    }
+}

src/Illuminate/Routing/ResponseFactory.php

@@ -10,6 +10,7 @@
 use Illuminate\Support\Traits\Macroable;
 use Symfony\Component\HttpFoundation\BinaryFileResponse;
 use Symfony\Component\HttpFoundation\StreamedResponse;
+use Throwable;
 
 class ResponseFactory implements FactoryContract
 {
@@ -138,7 +139,15 @@ public function stream($callback, $status = 200, array $headers = [])
      */
     public function streamDownload($callback, $name = null, array $headers = [], $disposition = 'attachment')
     {
-        $response = new StreamedResponse($callback, 200, $headers);
+        $withWrappedException = function () use ($callback) {
+            try {
+                $callback();
+            } catch (Throwable $e) {
+                throw new StreamedResponseException($e);
+            }
+        };
+
+        $response = new StreamedResponse($withWrappedException, 200, $headers);
 
         if (! is_null($name)) {
             $response->headers->set('Content-Disposition', $response->headers->makeDisposition(