From 9e6887470754489b4c9e218d5ebf8d1e4172096a Mon Sep 17 00:00:00 2001
From: Remon van de Kamp <rpkamp@gmail.com>
Date: Mon, 8 Oct 2018 20:52:36 +0200
Subject: [PATCH] Invalidate Translator cache when new translation files are
 added

Just before writing the Translator cache, find out in which directories
the translation files were found, and add those directories as resources
for the catalogue so that when a new file appears in one of those
directories the catalogue cache will be invalidated.

This may cause some false positives in case non-translation files are in
those directories, but since the recommendation is to keep translations
on their own, it should not happen.
---
 .../Component/Translation/Translator.php      | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/Symfony/Component/Translation/Translator.php b/src/Symfony/Component/Translation/Translator.php
index d8d27301f04df..a4efdd15438b3 100644
--- a/src/Symfony/Component/Translation/Translator.php
+++ b/src/Symfony/Component/Translation/Translator.php
@@ -14,6 +14,8 @@
 use Symfony\Component\Config\ConfigCacheFactory;
 use Symfony\Component\Config\ConfigCacheFactoryInterface;
 use Symfony\Component\Config\ConfigCacheInterface;
+use Symfony\Component\Config\Resource\DirectoryResource;
+use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\Translation\Exception\InvalidArgumentException;
 use Symfony\Component\Translation\Exception\LogicException;
 use Symfony\Component\Translation\Exception\NotFoundResourceException;
@@ -333,6 +335,10 @@ private function dumpCatalogue($locale, ConfigCacheInterface $cache): void
             $fallbackContent
         );
 
+        foreach ($this->getDirectoryResources($locale) as $dir) {
+            $this->catalogues[$locale]->addResource($dir);
+        }
+
         $cache->write($content, $this->catalogues[$locale]->getResources());
     }
 
@@ -463,4 +469,34 @@ private function getConfigCacheFactory(): ConfigCacheFactoryInterface
 
         return $this->configCacheFactory;
     }
+
+    /**
+     * Fetches a unique list of directories where files were found
+     * for a catalogue.
+     *
+     * @param string $locale
+     *
+     * @return DirectoryResource[]|array
+     */
+    private function getDirectoryResources($locale): array
+    {
+        $directories = array();
+        foreach ($this->catalogues[$locale]->getResources() as $resource) {
+            if (!$resource instanceof FileResource) {
+                continue;
+            }
+
+            $directory = \dirname($resource->getResource());
+            if (!\in_array($directory, $directories, true)) {
+                $directories[] = $directory;
+            }
+        }
+
+        return \array_map(
+            function ($directory) {
+                return new DirectoryResource($directory);
+            },
+            $directories
+        );
+    }
 }