Ignore Errno::ENAMETOOLONG exception when exporting project uploads

changelogs/unreleased/georgekoltsov-ignore-failed-to-download-project-export-uploads.yml

+---
+title: Fix 'File name too long' error happening during Project Export when exporting
+  project uploads
+merge_request: 46674
+author:
+type: fixed

lib/gitlab/import_export/uploads_manager.rb

@@ -86,6 +86,10 @@ module Gitlab
         mkdir_p(File.join(uploads_export_path, secret))
 
         download_or_copy_upload(upload, upload_path)
+      rescue Errno::ENAMETOOLONG => e
+        # Do not fail entire project export if downloaded file has filename that exceeds 255 characters.
+        # Ignore raised exception, skip such upload, log the error and keep going with the export instead.
+        Gitlab::ErrorTracking.log_exception(e, project_id: @project.id)
       end
     end
   end

spec/lib/gitlab/import_export/uploads_manager_spec.rb

@@ -23,13 +23,13 @@ RSpec.describe Gitlab::ImportExport::UploadsManager do
   end
 
   describe '#save' do
+    before do
+      project.uploads << upload
+    end
+
     context 'when the project has uploads locally stored' do
       let(:upload) { create(:upload, :issuable_upload, :with_file, model: project) }
 
-      before do
-        project.uploads << upload
-      end
-
       it 'does not cause errors' do
         manager.save
 
@@ -74,6 +74,22 @@ RSpec.describe Gitlab::ImportExport::UploadsManager do
         end
       end
     end
+
+    context 'when upload is in object storage' do
+      before do
+        stub_uploads_object_storage(FileUploader)
+        allow(manager).to receive(:download_or_copy_upload).and_raise(Errno::ENAMETOOLONG)
+      end
+
+      it 'ignores problematic upload and logs exception' do
+        expect(Gitlab::ErrorTracking).to receive(:log_exception).with(instance_of(Errno::ENAMETOOLONG), project_id: project.id)
+
+        manager.save
+
+        expect(shared.errors).to be_empty
+        expect(File).not_to exist(exported_file_path)
+      end
+    end
   end
 
   describe '#restore' do