fix test cases

src/documents/tests/test_merge.py

@@ -26,7 +26,7 @@ class TestPdfCache(DirectoriesMixin, TestCase):
 
     def test_open_no_pdf(self):
         doc = Document.objects.create(mime_type="image/jpeg")
-        self.assertRaisesMessage(MergeError, "does not have PDF.", self.cache.open_from_document, doc)
+        self.assertRaisesMessage(MergeError, "does not have a PDF.", self.cache.open_from_document, doc)
 
     def test_open_original_pdf(self):
         doc = Document.objects.create(mime_type="application/pdf", filename="test.pdf")

src/documents/views.py

@@ -675,6 +675,7 @@ class DocumentSplitMergeViewSet(GenericViewSet):
                 tempdir=self.tempdir
             )
         except MergeError:
-            raise
+            logger.exception("Error during merge")
+            return HttpResponseBadRequest()
 
         return Response([os.path.basename(file) for file in pdf_files])