Histogram: Respect min/max panel settings for x-axis (#62273)

public/app/plugins/panel/histogram/Histogram.tsx

@@ -53,6 +53,10 @@ export function getBucketSize(frame: DataFrame) {
 const prepConfig = (frame: DataFrame, theme: GrafanaTheme2) => {
   // todo: scan all values in BucketMin and BucketMax fields to assert if uniform bucketSize
 
+  // since this is x axis range, this should ideally come from xMin or xMax fields, not a count field
+  // though both methods are probably hacks, and we should just accept explicit opts into this prepConfig
+  let { min: xScaleMin, max: xScaleMax } = frame.fields[2].config;
+
   let builder = new UPlotConfigBuilder();
 
   // assumes BucketMin is fields[0] and BucktMax is fields[1]
@@ -64,8 +68,8 @@ const prepConfig = (frame: DataFrame, theme: GrafanaTheme2) => {
     let minSpace = u.axes[axisIdx]._space;
     let bucketWidth = u.valToPos(u.data[0][0] + bucketSize, 'x') - u.valToPos(u.data[0][0], 'x');
 
-    let firstSplit = u.data[0][0];
-    let lastSplit = u.data[0][u.data[0].length - 1] + bucketSize;
+    let firstSplit = incrRoundDn(xScaleMin ?? u.data[0][0], bucketSize);
+    let lastSplit = incrRoundUp(xScaleMax ?? u.data[0][u.data[0].length - 1] + bucketSize, bucketSize);
 
     let splits = [];
     let skip = Math.ceil(minSpace / bucketWidth);
@@ -84,6 +88,14 @@ const prepConfig = (frame: DataFrame, theme: GrafanaTheme2) => {
     orientation: ScaleOrientation.Horizontal,
     direction: ScaleDirection.Right,
     range: (u, wantedMin, wantedMax) => {
+      // these settings will prevent zooming, probably okay?
+      if (xScaleMin != null) {
+        wantedMin = xScaleMin;
+      }
+      if (xScaleMax != null) {
+        wantedMax = xScaleMax;
+      }
+
       let fullRangeMin = u.data[0][0];
       let fullRangeMax = u.data[0][u.data[0].length - 1];