Guarded cases when min and max values of charts are equal.

Telegram/SourceFiles/statistics/statistics_data_deserialize.cpp

@@ -80,6 +80,13 @@ Data::StatisticalChart StatisticalChartFromJSON(const QByteArray &json) {
 		}
 		result.measure();
 	}
+	if (result.maxValue == result.minValue) {
+		if (result.minValue) {
+			result.minValue = 0;
+		} else {
+			result.maxValue = 1;
+		}
+	}
 
 	{
 		const auto subchart = root.value(u"subchart"_q).toObject();

Telegram/SourceFiles/statistics/view/linear_chart_view.cpp

@@ -256,6 +256,10 @@ AbstractChartView::HeightLimits LinearChartView::heightLimits(
 		maxValueFull = std::max(int(l.maxValue * r), maxValueFull);
 		minValueFull = std::min(int(l.minValue * r), minValueFull);
 	}
+	if (maxValue == minValue) {
+		maxValue = chartData.maxValue;
+		minValue = chartData.minValue;
+	}
 	return {
 		.full = Limits{ float64(minValueFull), float64(maxValueFull) },
 		.ranged = Limits{ float64(minValue), float64(maxValue) },

Telegram/SourceFiles/statistics/view/stack_chart_view.cpp

@@ -167,9 +167,11 @@ AbstractChartView::HeightLimits StackChartView::heightLimits(
 			_cachedHeightLimits.ySum);
 		_cachedHeightLimits.full = { 0., float64(maxValueFull) };
 	}
-	const auto max = _cachedHeightLimits.ySumSegmentTree.rMaxQ(
-		xIndices.min,
-		xIndices.max);
+	const auto max = std::max(
+		_cachedHeightLimits.ySumSegmentTree.rMaxQ(
+			xIndices.min,
+			xIndices.max),
+		1);
 	return {
 		.full = _cachedHeightLimits.full,
 		.ranged = { 0., float64(max) },