Unit test for non-reproducable #58747

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1720588 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/testcases/org/apache/poi/xssf/eventusermodel/TestXSSFReader.java

@@ -27,6 +27,7 @@ import org.apache.poi.openxml4j.opc.OPCPackage;
 import org.apache.poi.util.IOUtils;
 import org.apache.poi.xssf.XSSFTestDataSamples;
 import org.apache.poi.xssf.model.CommentsTable;
+import org.apache.poi.xssf.model.StylesTable;
 import org.apache.poi.xssf.usermodel.XSSFRichTextString;
 import org.apache.poi.xssf.usermodel.XSSFShape;
 import org.apache.poi.xssf.usermodel.XSSFSimpleShape;
@@ -196,4 +197,22 @@ public final class TestXSSFReader extends TestCase {
        assertTrue(text.indexOf("Line 3") > -1);
 
    }
+   
+   /**
+    * NPE from XSSFReader$SheetIterator.<init> on XLSX files generated by 
+    *  the openpyxl library
+    */
+   public void test58747() throws Exception {
+       OPCPackage pkg =  XSSFTestDataSamples.openSamplePackage("58747.xlsx");
+       ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(pkg);
+       XSSFReader reader = new XSSFReader(pkg);
+       StylesTable styles = reader.getStylesTable();
+       
+       XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) reader.getSheetsData();
+       assertEquals(true, iter.hasNext());
+       iter.next();
+       
+       assertEquals(false, iter.hasNext());
+       assertEquals("Orders", iter.getSheetName());
+   }
 }