Datasource/Elasticsearch: Fix logs which were displayed with incorrect timestamp in Explore logs tab (#20009)

packages/grafana-data/src/dataframe/MutableDataFrame.test.ts

@@ -57,6 +57,16 @@ describe('Apending DataFrame', () => {
       { time: null, name: null, value: null, value2: 'XXX' }, // 4
     ]);
 
+    // Add a time value that has an array type
+    frame.add({ time: [300] });
+    expect(frame.toArray()).toEqual([
+      { time: 100, name: 'a', value: 1, value2: null }, // 1
+      { time: 200, name: 'BB', value: 20, value2: null }, // 2
+      { time: null, name: null, value: 3, value2: null }, // 3
+      { time: null, name: null, value: null, value2: 'XXX' }, // 4
+      { time: 300, name: null, value: null, value2: null }, // 5
+    ]);
+
     // Make sure length survives a spread operator
     const keys = Object.keys(frame);
     const copy = { ...frame } as any;

packages/grafana-data/src/dataframe/MutableDataFrame.ts

@@ -234,6 +234,11 @@ export class MutableDataFrame<T = any> implements DataFrame, MutableVector<T> {
           field.parse = makeFieldParser(val, field);
         }
         val = field.parse(val);
+      } else if (field.type === FieldType.time && isArray(val)) {
+        if (!field.parse) {
+          field.parse = (val: any[]) => val[0] || undefined;
+        }
+        val = field.parse(val);
       }
 
       if (val === undefined) {