getDataLabel() defends against empty labels

Author: yfinkel

src/PhpSpreadsheet/Chart/Renderer/JpGraphRendererBase.php

@@ -757,7 +757,7 @@ private function renderCombinationChart($groupCount, $outputDestination): bool
                     break;
                 case 'bar3DChart':
                     $dimensions = '3d';
-                // no break
+                    // no break
                 case 'barChart':
                     $this->renderPlotBar($i, $dimensions);
 
@@ -818,35 +818,35 @@ public function render(?string $outputDestination): bool
         switch ($chartType) {
             case 'area3DChart':
                 $dimensions = '3d';
-            // no break
+                // no break
             case 'areaChart':
                 $this->renderAreaChart($groupCount);
 
                 break;
             case 'bar3DChart':
                 $dimensions = '3d';
-            // no break
+                // no break
             case 'barChart':
                 $this->renderBarChart($groupCount, $dimensions);
 
                 break;
             case 'line3DChart':
                 $dimensions = '3d';
-            // no break
+                // no break
             case 'lineChart':
                 $this->renderLineChart($groupCount);
 
                 break;
             case 'pie3DChart':
                 $dimensions = '3d';
-            // no break
+                // no break
             case 'pieChart':
                 $this->renderPieChart($groupCount, $dimensions, false, false);
 
                 break;
             case 'doughnut3DChart':
                 $dimensions = '3d';
-            // no break
+                // no break
             case 'doughnutChart':
                 $this->renderPieChart($groupCount, $dimensions, true, true);