echarts+5.5.0.patch

diff --git a/node_modules/echarts/lib/chart/line/LineView.js b/node_modules/echarts/lib/chart/line/LineView.js
index 9da26b6..edf6ed7 100644
--- a/node_modules/echarts/lib/chart/line/LineView.js
+++ b/node_modules/echarts/lib/chart/line/LineView.js
@@ -140,6 +140,9 @@ function turnPointsIntoStep(points, coordSys, stepTurnAt, connectNulls) {
     pt[0] = points[i];
     pt[1] = points[i + 1];
     stepPoints.push(pt[0], pt[1]);
+    if (isNaN(nextPt[1 - baseIndex])) {
+      continue;
+    }
     switch (stepTurnAt) {
       case 'end':
         stepPt[baseIndex] = nextPt[baseIndex];
diff --git a/node_modules/echarts/lib/chart/line/helper.js b/node_modules/echarts/lib/chart/line/helper.js
index fa02e2f..c84b0ac 100644
--- a/node_modules/echarts/lib/chart/line/helper.js
+++ b/node_modules/echarts/lib/chart/line/helper.js
@@ -108,16 +108,20 @@ function getValueStart(valueAxis, valueOrigin) {
   return valueStart;
 }
 export function getStackedOnPoint(dataCoordInfo, coordSys, data, idx) {
-  var value = NaN;
+  let stackedOverValue = NaN;
+  let stackResultValue = NaN;
   if (dataCoordInfo.stacked) {
-    value = data.get(data.getCalculationInfo('stackedOverDimension'), idx);
+    stackedOverValue = data.get(data.getCalculationInfo('stackedOverDimension'), idx);
+    stackResultValue = data.get(data.getCalculationInfo('stackResultDimension'), idx);
+  } else {
+    stackResultValue = data.get(dataCoordInfo.valueDim, idx);
   }
-  if (isNaN(value)) {
-    value = dataCoordInfo.valueStart;
+  if (isNaN(stackedOverValue) && !isNaN(stackResultValue)) {
+    stackedOverValue = dataCoordInfo.valueStart;
   }
   var baseDataOffset = dataCoordInfo.baseDataOffset;
   var stackedData = [];
   stackedData[baseDataOffset] = data.get(dataCoordInfo.baseDim, idx);
-  stackedData[1 - baseDataOffset] = value;
+  stackedData[1 - baseDataOffset] = stackedOverValue;
   return coordSys.dataToPoint(stackedData);
 }
diff --git a/node_modules/echarts/lib/data/helper/dataStackHelper.js b/node_modules/echarts/lib/data/helper/dataStackHelper.js
index c25de1b..a3ced22 100644
--- a/node_modules/echarts/lib/data/helper/dataStackHelper.js
+++ b/node_modules/echarts/lib/data/helper/dataStackHelper.js
@@ -83,6 +83,13 @@ export function enableDataStack(seriesModel, dimensionsInput, opt) {
   var stackedDimInfo;
   var stackResultDimension;
   var stackedOverDimension;
+
+  var yCoordDimension = dimensionDefineList.find(
+    dimensionInfo => !isString(dimensionInfo) && dimensionInfo.coordDim === 'y'
+  );
+  var isYCoordDimensionStackable = yCoordDimension != null
+    && yCoordDimension.type !== 'ordinal' && yCoordDimension.type !== 'time';
+
   each(dimensionDefineList, function (dimensionInfo, index) {
     if (isString(dimensionInfo)) {
       dimensionDefineList[index] = dimensionInfo = {
@@ -95,7 +102,10 @@ export function enableDataStack(seriesModel, dimensionsInput, opt) {
         stackedByDimInfo = dimensionInfo;
       }
       // Find the first stackable dimension as the stackedDimInfo.
-      if (!stackedDimInfo && dimensionInfo.type !== 'ordinal' && dimensionInfo.type !== 'time' && (!stackedCoordDimension || stackedCoordDimension === dimensionInfo.coordDim)) {
+      if (!stackedDimInfo && dimensionInfo.type !== 'ordinal'
+          && dimensionInfo.type !== 'time'
+          && (yCoordDimension == null || (dimensionInfo.coordDim !== 'x' && isYCoordDimensionStackable))
+          && (!stackedCoordDimension || stackedCoordDimension === dimensionInfo.coordDim)) {
         stackedDimInfo = dimensionInfo;
       }
     }
@@ -105,6 +115,11 @@ export function enableDataStack(seriesModel, dimensionsInput, opt) {
     // It may make sense if the user provides elaborately constructed data.
     byIndex = true;
   }
+  if (stackedDimInfo && !byIndex && !stackedByDimInfo) {
+    // Compatible with previous design, value axis (time axis) only stack by index.
+    // It may make sense if the user provides elaborately constructed data.
+    byIndex = true;
+  }
   // Add stack dimension, they can be both calculated by coordinate system in `unionExtent`.
   // That put stack logic in List is for using conveniently in echarts extensions, but it
   // might not be a good way.
diff --git a/node_modules/echarts/lib/label/labelLayoutHelper.js b/node_modules/echarts/lib/label/labelLayoutHelper.js
index a75f606..52c5a0b 100644
--- a/node_modules/echarts/lib/label/labelLayoutHelper.js
+++ b/node_modules/echarts/lib/label/labelLayoutHelper.js
@@ -256,6 +256,13 @@ export function hideOverlap(labelList) {
     var transform = labelItem.transform;
     var label = labelItem.label;
     var labelLine = labelItem.labelLine;
+    
+    if (label.style.text === "") {
+      hideEl(label);
+      labelLine && hideEl(labelLine);
+      continue;
+    }
+    
     globalRect.copy(labelItem.rect);
     // Add a threshold because layout may be aligned precisely.
     globalRect.width -= 0.1;