fix(echarts): fix stacked horizontal bar chart clipping and duplicate x-axis labels

superset-frontend/plugins/plugin-chart-echarts/src/Timeseries/transformProps.ts

@@ -659,7 +659,10 @@ export default function transformProps(
     for (const s of series) {
       if (s.id) {
         const columnsArr = labelMap[s.id];
-        (s as any).stack = columnsArr[idxSelectedDimension];
+        const dimensionValue = columnsArr?.[idxSelectedDimension];
+        if (dimensionValue !== undefined) {
+          (s as any).stack = dimensionValue;
+        }
       }
     }
   }
@@ -682,9 +685,24 @@ export default function transformProps(
 
   // For horizontal bar charts, set max/min from calculated data bounds
   if (shouldCalculateDataBounds) {
-    // Set max to actual data max to avoid gaps and ensure labels are visible
-    if (dataMax !== undefined && yAxisMax === undefined) {
-      yAxisMax = dataMax;
+    // For stacked charts, clamp against the per-row stacked total to avoid
+    // clipping bars. Also keep dataMax so that mixed-sign stacks (where
+    // positive and negative values cancel in the algebraic row sum) cannot
+    // produce an axis max smaller than the largest individual positive segment.
+    const stackedTotalMax = Math.max(
+      ...sortedTotalValues.filter(
+        (v): v is number => typeof v === 'number' && !Number.isNaN(v),
+      ),
+    );
+    const effectiveDataMax = stack
+      ? Math.max(dataMax ?? Number.NEGATIVE_INFINITY, stackedTotalMax)
+      : dataMax;
+    if (
+      effectiveDataMax !== undefined &&
+      Number.isFinite(effectiveDataMax) &&
+      yAxisMax === undefined
+    ) {
+      yAxisMax = effectiveDataMax;
     }
     // Set min to actual data min for diverging bars
     if (dataMin !== undefined && yAxisMin === undefined && dataMin < 0) {

superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/Bar/transformProps.test.ts

@@ -24,6 +24,7 @@ import {
 } from '@superset-ui/core';
 import { GenericDataType } from '@apache-superset/core/common';
 import { supersetTheme } from '@apache-superset/core/theme';
+import { StackControlsValue } from '../../../src/constants';
 import type {
   GridComponentOption,
   LegendComponentOption,
@@ -727,6 +728,97 @@ describe('Bar Chart X-axis Time Formatting', () => {
     });
   });
 
+  describe('Horizontal stacked bar chart axis bounds', () => {
+    // Dataset where each series max = 4 but stacked total max = 8
+    const stackedData: ChartDataResponseResult[] = [
+      createTestQueryData(
+        [
+          { team: 'Team A', High: 2, Low: 2, Medium: 4 },
+          { team: 'Team B', High: null, Low: null, Medium: 3 },
+          { team: 'Team C', High: null, Low: null, Medium: 1 },
+        ],
+        {
+          colnames: ['team', 'High', 'Low', 'Medium'],
+          coltypes: [
+            GenericDataType.String,
+            GenericDataType.Numeric,
+            GenericDataType.Numeric,
+            GenericDataType.Numeric,
+          ],
+        },
+      ),
+    ];
+
+    const horizontalStackedFormData: EchartsTimeseriesFormData = {
+      ...(baseFormData as EchartsTimeseriesFormData),
+      x_axis: 'team',
+      metric: ['High', 'Low', 'Medium'],
+      groupby: [],
+      orientation: OrientationType.Horizontal,
+      seriesType: EchartsTimeseriesSeriesType.Bar,
+      stack: StackControlsValue.Stack,
+      truncateYAxis: true,
+    };
+
+    test('xAxis.max uses stacked total, not individual series max', () => {
+      // Individual series max = 4 (Medium), stacked total for Team A = 8
+      // Without the fix, xAxis.max would be 4, clipping bars and duplicating labels
+      const chartProps = createEchartsTimeseriesTestChartProps<
+        EchartsTimeseriesFormData,
+        EchartsTimeseriesChartProps
+      >({
+        defaultFormData: horizontalStackedFormData,
+        defaultVizType: 'echarts_timeseries_bar',
+        defaultQueriesData: stackedData,
+      });
+
+      const { echartOptions } = transformProps(chartProps);
+      const xAxis = echartOptions.xAxis as any;
+
+      // xAxis.max must be >= stacked total (8), not capped at individual series max (4)
+      expect(xAxis.max).toBeGreaterThanOrEqual(8);
+    });
+
+    test('xAxis.max is not set to individual series max when stacking', () => {
+      const chartProps = createEchartsTimeseriesTestChartProps<
+        EchartsTimeseriesFormData,
+        EchartsTimeseriesChartProps
+      >({
+        defaultFormData: horizontalStackedFormData,
+        defaultVizType: 'echarts_timeseries_bar',
+        defaultQueriesData: stackedData,
+      });
+
+      const { echartOptions } = transformProps(chartProps);
+      const xAxis = echartOptions.xAxis as any;
+
+      // 4 is the individual series max — the axis should not be clipped there
+      expect(xAxis.max).not.toBe(4);
+    });
+
+    test('non-stacked horizontal bar chart still uses individual series max', () => {
+      const nonStackedFormData: EchartsTimeseriesFormData = {
+        ...horizontalStackedFormData,
+        stack: null,
+      };
+
+      const chartProps = createEchartsTimeseriesTestChartProps<
+        EchartsTimeseriesFormData,
+        EchartsTimeseriesChartProps
+      >({
+        defaultFormData: nonStackedFormData,
+        defaultVizType: 'echarts_timeseries_bar',
+        defaultQueriesData: stackedData,
+      });
+
+      const { echartOptions } = transformProps(chartProps);
+      const xAxis = echartOptions.xAxis as any;
+
+      // Without stacking, xAxis.max should be based on individual series values
+      expect(xAxis.max).toBe(4);
+    });
+  });
+
   describe('Legend layout regressions', () => {
     const getBottomLegendLayout = (
       chartWidth: number,