fixup! WIP feat(cosmos): Export KVData as artifact

Refactor payloadReader loop

golang/cosmos/x/swingset/keeper/snapshotter.go

@@ -332,22 +332,24 @@ func (snapshotter *SwingsetSnapshotter) RestoreExtension(height uint64, format u
 			return err
 		}
 
-		filename := artifactNameSanitizer.ReplaceAllString(filepath.Base(payload.Name), "-")
-		filename = fmt.Sprintf("%d-%s", len(manifest.Artifacts), filename)
-		manifest.Artifacts = append(manifest.Artifacts, [2]string{payload.Name, filename})
-		err = writeExportFile(filename, payload.Data)
-
-		if payload.Name == UntrustedExportDataArtifactName {
-			if len(swingStoreEntries) == 0 {
-				snapshotter.logger().Info("using unverified export data for swingstore restore")
-				_, err := exportDataFile.Write(payload.Data)
-				if err != nil {
-					return err
-				}
-				continue
-			} else {
-				filename = UntrustedExportDataFilename
-			}
+		switch {
+		case payload.Name != UntrustedExportDataArtifactName:
+			// Artifact verifiable on import from the export data
+			filename := artifactNameSanitizer.ReplaceAllString(filepath.Base(payload.Name), "-")
+			filename = fmt.Sprintf("%d-%s", len(manifest.Artifacts), filename)
+			manifest.Artifacts = append(manifest.Artifacts, [2]string{payload.Name, filename})
+			err = writeExportFile(filename, payload.Data)
+
+		case len(swingStoreEntries) > 0:
+			// Pseudo artifact containing untrusted export data which may have been
+			// saved separately for debugging purposes (not referenced from the manifest)
+			err = writeExportFile(UntrustedExportDataFilename, payload.Data)
+
+		default:
+			// There is no trusted export data, so use any untrusted export data artifact
+			// FIXME: Remove. Only useful if streamed export data is disabled
+			snapshotter.logger().Info("using unverified export data for swingstore restore")
+			_, err = exportDataFile.Write(payload.Data)
 		}
 
 		if err != nil {