Throw an exception when signing route if a parameter key is 'signature'

src/Illuminate/Routing/UrlGenerator.php

@@ -315,11 +315,19 @@ public function formatScheme($secure = null)
      * @param  \DateTimeInterface|\DateInterval|int|null  $expiration
      * @param  bool  $absolute
      * @return string
+     *
+     * @throws \InvalidArgumentException
      */
     public function signedRoute($name, $parameters = [], $expiration = null, $absolute = true)
     {
         $parameters = $this->formatParameters($parameters);
 
+        if(array_key_exists('signature', $parameters)) {
+            throw new InvalidArgumentException(
+                'Do not use [signature] as a parameter name when creating a signed route.'
+            );
+        }
+
         if ($expiration) {
             $parameters = $parameters + ['expires' => $this->availableAt($expiration)];
         }

tests/Routing/RoutingUrlGeneratorTest.php

@@ -8,6 +8,7 @@
 use Illuminate\Routing\Route;
 use Illuminate\Routing\RouteCollection;
 use Illuminate\Routing\UrlGenerator;
+use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Request as SymfonyRequest;
 use Symfony\Component\Routing\Exception\RouteNotFoundException;
@@ -627,6 +628,26 @@ public function testSignedRelativeUrl()
 
         $this->assertFalse($url->hasValidSignature($request, false));
     }
+
+    public function testSignedUrlParameterCannotBeNamedSignature() {
+        $url = new UrlGenerator(
+            $routes = new RouteCollection,
+            $request = Request::create('http://www.foo.com/')
+        );
+        $url->setKeyResolver(function () {
+            return 'secret';
+        });
+
+        $route = new Route(['GET'], 'foo/{signature}', ['as' => 'foo', function () {
+            //
+        }]);
+        $routes->add($route);
+
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Do not use [signature] as a parameter name when creating a signed route.');
+
+        Request::create($url->signedRoute('foo', ['signature' => 'bar']));
+    }
 }
 
 class RoutableInterfaceStub implements UrlRoutable