[ATTACHMENTS] Don't store an attachment if it's a dupplicate, reuse it

src/Core/GSFile.php

@@ -22,12 +22,12 @@
 namespace App\Core;
 
 use App\Core\DB\DB;
-use App\Util\Exception\NotFoundException;
 use function App\Core\I18n\_m;
 use App\Entity\Attachment;
 use App\Util\Common;
 use App\Util\Exception\ClientException;
 use App\Util\Exception\NoSuchFileException;
+use App\Util\Exception\NotFoundException;
 use App\Util\Exception\ServerException;
 use Symfony\Component\HttpFoundation\BinaryFileResponse;
 use Symfony\Component\HttpFoundation\File\File as SymfonyFile;
@@ -46,6 +46,9 @@ class GSFile
                                                             int $actor_id = null): Attachment
     {
         Event::handle('HashFile', [$sfile->getPathname(), &$hash]);
+        try {
+            return DB::findOneBy('attachment', ['file_hash' => $hash]);
+        } catch (NotFoundException) {
             // The following properly gets the mimetype with `file` or other
             // available methods, so should be safe
             $mimetype = $sfile->getMimeType();
@@ -66,6 +69,7 @@ class GSFile
             Event::handle('AttachmentStoreNew', [&$attachment]);
             return $attachment;
         }
+    }
 
     /**
      * Create an attachment for the given URL, fetching the mimetype