Avoid NPE on spreadsheetDrawing row tags

src/main/java/com/monitorjbl/xlsx/impl/StreamingSheetReader.java

@@ -87,7 +87,8 @@ private void handleEvent(XMLEvent event) throws SAXException {
     if(event.getEventType() == XMLStreamConstants.CHARACTERS) {
       Characters c = event.asCharacters();
       lastContents += c.getData();
-    } else if(event.getEventType() == XMLStreamConstants.START_ELEMENT) {
+    } else if(event.getEventType() == XMLStreamConstants.START_ELEMENT
+            && isSpreadsheetTag(event.asStartElement().getName())) {
       StartElement startElement = event.asStartElement();
       String tagLocalName = startElement.getName().getLocalPart();
 
@@ -152,7 +153,8 @@ private void handleEvent(XMLEvent event) throws SAXException {
 
       // Clear contents cache
       lastContents = "";
-    } else if(event.getEventType() == XMLStreamConstants.END_ELEMENT) {
+    } else if(event.getEventType() == XMLStreamConstants.END_ELEMENT
+            && isSpreadsheetTag(event.asEndElement().getName())) {
       EndElement endElement = event.asEndElement();
       String tagLocalName = endElement.getName().getLocalPart();
 
@@ -170,6 +172,21 @@ private void handleEvent(XMLEvent event) throws SAXException {
     }
   }
 
+  /**
+   * Returns true if a tag is part of the main namespace for SpreadsheetML:
+   * <ul>
+   * <li>http://schemas.openxmlformats.org/spreadsheetml/2006/main
+   * <li>http://purl.oclc.org/ooxml/spreadsheetml/main
+   * </ul>
+   * As opposed to http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing, etc.
+   * @param name
+   * @return
+   */
+  private boolean isSpreadsheetTag(QName name) {
+    return (name.getNamespaceURI() != null
+      && name.getNamespaceURI().endsWith("/main"));
+  }
+
   /**
    * Get the hidden state for a given column
    *

src/test/java/com/monitorjbl/xlsx/StreamingReaderTest.java

@@ -480,4 +480,17 @@ public void testClosingFiles() throws Exception {
     OPCPackage o = OPCPackage.open(new File("src/test/resources/blank_cell_StringCellValue.xlsx"), PackageAccess.READ);
     o.close();
   }
+
+  @Test
+  public void shouldIgnoreSpreadsheetDrawingRows() throws Exception {
+    try(
+        InputStream is = new FileInputStream(new File("src/test/resources/has_spreadsheetdrawing.xlsx"));
+        StreamingReader reader = StreamingReader.builder().read(is);
+    ) {
+      Iterator<Row> iterator = reader.iterator();
+      while(iterator.hasNext()) {
+        iterator.next();
+      }
+    }
+  }
 }