SY-4149: Add length guard

Author: sy-nico

pluto/src/telem/aether/convertSeries.spec.ts

@@ -92,6 +92,16 @@ describe("convertSeriesToSupportedGL", () => {
     const result = convertSeriesToSupportedGL(series, offset);
     expect(result.sampleOffset).toBe(offset);
   });
+
+  it("does not throw on a zero-length bigint series with no explicit offset", () => {
+    const series = new Series({
+      data: new BigInt64Array(0),
+      dataType: DataType.INT64,
+    });
+    const result = convertSeriesToSupportedGL(series);
+    expect(result.dataType.equals(DataType.FLOAT32)).toBe(true);
+    expect(result).toHaveLength(0);
+  });
 });
 
 describe("resolveGLDataType", () => {

pluto/src/telem/aether/convertSeries.ts

@@ -29,7 +29,8 @@ export const convertSeriesToSupportedGL = (
 ): Series => {
   if (series.dataType.isVariable || series.dataType.equals(DataType.UINT8))
     return series;
-  if (offset == null && series.dataType.usesBigInt) offset = BigInt(series.data[0]);
+  if (offset == null && series.dataType.usesBigInt && series.length > 0)
+    offset = BigInt(series.data[0]);
   return series.convert(DataType.FLOAT32, offset);
 };