InputDataSource: Fixed issue with config editor (#19818)

packages/grafana-data/src/utils/csv.ts

@@ -271,6 +271,12 @@ export function toCSV(data: DataFrame[], config?: CSVConfig): string {
 
   for (const series of data) {
     const { fields } = series;
+
+    // ignore frames with no fields
+    if (fields.length === 0) {
+      continue;
+    }
+
     if (config.headerStyle === CSVHeaderStyle.full) {
       csv =
         csv +
@@ -287,7 +293,9 @@ export function toCSV(data: DataFrame[], config?: CSVConfig): string {
       }
       csv += config.newline;
     }
+
     const length = fields[0].values.length;
+
     if (length > 0) {
       const writers = fields.map(field => makeFieldWriter(field, config!));
       for (let i = 0; i < length; i++) {