Fixing creating several baseline series with different base value

Fixes #898

src/api/chart-api.ts

@@ -227,7 +227,8 @@ export class ChartApi implements IChartApi, DataUpdatesConsumer<SeriesType> {
 		options = migrateOptions(options);
 		patchPriceFormat(options.priceFormat);
 
-		const strictOptions = merge(clone(seriesOptionsDefaults), baselineStyleDefaults, options) as BaselineSeriesOptions;
+		// baseline style defaults has an object in it so we have to clone it as well to avoid assigning fields to defaults
+		const strictOptions = merge(clone(seriesOptionsDefaults), clone(baselineStyleDefaults), options) as BaselineSeriesOptions;
 		const series = this._chartWidget.model().createSeries('Baseline', strictOptions);
 
 		const res = new SeriesApi<'Baseline'>(series, this, this);

tests/e2e/graphics/test-cases/series/2-baseline-series.js

@@ -0,0 +1,64 @@
+function generateData(valueOffset) {
+	const res = [];
+	const time = new Date(Date.UTC(2018, 0, 1, 0, 0, 0, 0));
+	for (let i = 0; i < 50; ++i) {
+		res.push({
+			time: time.getTime() / 1000,
+			value: i * (-1) + valueOffset,
+		});
+
+		time.setUTCDate(time.getUTCDate() + 1);
+	}
+
+	for (let i = 0; i < 100; ++i) {
+		res.push({
+			time: time.getTime() / 1000,
+			value: -50 + i + valueOffset,
+		});
+
+		time.setUTCDate(time.getUTCDate() + 1);
+	}
+
+	for (let i = 0; i < 100; ++i) {
+		res.push({
+			time: time.getTime() / 1000,
+			value: 50 - i + valueOffset,
+		});
+
+		time.setUTCDate(time.getUTCDate() + 1);
+	}
+
+	for (let i = 0; i < 100; ++i) {
+		res.push({
+			time: time.getTime() / 1000,
+			value: -50 + i + valueOffset,
+		});
+
+		time.setUTCDate(time.getUTCDate() + 1);
+	}
+	return res;
+}
+
+function runTestCase(container) {
+	const chart = LightweightCharts.createChart(container);
+
+	const firstSeries = chart.addBaselineSeries({
+		baseValue: {
+			type: 'price',
+			price: 0,
+		},
+	});
+
+	firstSeries.setData(generateData(0));
+
+	const secondSeries = chart.addBaselineSeries({
+		baseValue: {
+			type: 'price',
+			price: 100,
+		},
+	});
+
+	secondSeries.setData(generateData(100));
+
+	chart.timeScale().fitContent();
+}