From 2a88752cd6ab2bc9e7d06fdc48fbfc2b30f9b4ee Mon Sep 17 00:00:00 2001
From: "Alexander M. Turek" <me@derrabus.de>
Date: Fri, 28 Jun 2019 10:23:33 +0200
Subject: [PATCH] [Routing] Deprecate RouteCollection::addPrefix(null).

---
 src/Symfony/Component/Routing/RouteCollection.php        | 4 ++++
 src/Symfony/Component/Routing/RouteCollectionBuilder.php | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Routing/RouteCollection.php b/src/Symfony/Component/Routing/RouteCollection.php
index 6c642300a9..76b1a84d9c 100644
--- a/src/Symfony/Component/Routing/RouteCollection.php
+++ b/src/Symfony/Component/Routing/RouteCollection.php
@@ -140,6 +140,10 @@ class RouteCollection implements \IteratorAggregate, \Countable
      */
     public function addPrefix($prefix, array $defaults = [], array $requirements = [])
     {
+        if (null === $prefix) {
+            @trigger_error(sprintf('Passing null as $prefix to %s is deprecated in Symfony 4.4 and will trigger a TypeError in 5.0.', __METHOD__), E_USER_DEPRECATED);
+        }
+
         $prefix = trim(trim($prefix), '/');
 
         if ('' === $prefix) {
diff --git a/src/Symfony/Component/Routing/RouteCollectionBuilder.php b/src/Symfony/Component/Routing/RouteCollectionBuilder.php
index eb0585bdf6..86013a3fa3 100644
--- a/src/Symfony/Component/Routing/RouteCollectionBuilder.php
+++ b/src/Symfony/Component/Routing/RouteCollectionBuilder.php
@@ -309,7 +309,9 @@ class RouteCollectionBuilder
             } else {
                 /* @var self $route */
                 $subCollection = $route->build();
-                $subCollection->addPrefix($this->prefix);
+                if (null !== $this->prefix) {
+                    $subCollection->addPrefix($this->prefix);
+                }
 
                 $routeCollection->addCollection($subCollection);
             }