fix: keep upload files until their deletion is committed

src/Controller/Teamer/Disposition/DetailController.php

@@ -79,6 +79,14 @@ class DetailController extends AbstractController
 
     private function uploadContract(Disposition $disposition, UploadSessionDto $uploadSession): void
     {
+        // The session can hold files of other types, so a non-empty session alone does not
+        // mean there is anything to replace the existing document with.
+        if (true === $uploadSession->getUploadsByType(Upload::TYPE_CONTRACT)->isEmpty()) {
+            $this->addFlash('error', 'Bitte lade zuerst den Honorarvertrag hoch');
+
+            return;
+        }
+
         if (null !== $existingUpload = $disposition->getDocumentByType(Upload::TYPE_CONTRACT)) {
             $this->entityManager->remove($existingUpload);
         }
@@ -116,6 +124,14 @@ class DetailController extends AbstractController
 
     private function uploadInvoice(Disposition $disposition, UploadSessionDto $uploadSession): void
     {
+        // The session can hold files of other types, so a non-empty session alone does not
+        // mean there is anything to replace the existing document with.
+        if (true === $uploadSession->getUploadsByType(Upload::TYPE_INVOICE)->isEmpty()) {
+            $this->addFlash('error', 'Bitte lade zuerst die Honorarnote hoch');
+
+            return;
+        }
+
         if (null !== $existingUpload = $disposition->getDocumentByType(Upload::TYPE_INVOICE)) {
             $this->entityManager->remove($existingUpload);
         }