Add tests

Author: rpg600

src/PhpSpreadsheet/Reader/Xlsx.php

@@ -1714,10 +1714,6 @@ protected function loadSpreadsheetFromFile(string $filename): Spreadsheet
                                                 }
                                             }
                                         }
-                                        if (empty($relsDrawing) && $xmlDrawing->count() == 0) {
-                                            // Save Drawing without rels and children as unparsed
-                                            $unparsedDrawings[$drawingRelId] = $xmlDrawing->asXML();
-                                        }
                                     }
 
                                     // store original rId of drawing files

src/PhpSpreadsheet/Writer/Xlsx/Drawing.php

@@ -599,15 +599,13 @@ private static function writeAttributeIf(XMLWriter $objWriter, ?bool $condition,
     }
 
     /**
-     * Get pass-through drawing XML if available and no drawings have been modified.
+     * Get pass-through drawing XML if available.
+     *
+     * Returns the original drawing XML stored during load (when Reader pass-through was enabled).
+     * This preserves unsupported drawing elements (shapes, textboxes) that PhpSpreadsheet cannot parse.
      */
     private function getPassThroughDrawingXml(\PhpOffice\PhpSpreadsheet\Worksheet\Worksheet $worksheet): ?string
     {
-        // Only use pass-through if no drawings have been added/modified programmatically
-        if (count($worksheet->getDrawingCollection()) !== 0) {
-            return null;
-        }
-
         $unparsedLoadedData = $worksheet->getParentOrThrow()->getUnparsedLoadedData();
         if (!isset($unparsedLoadedData['sheets']) || !is_array($unparsedLoadedData['sheets'])) {
             return null;