Bug 59427: Add a check to better report cases when a document is already closed.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1744306 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/POIXMLDocument.java

@@ -196,6 +196,10 @@ public abstract class POIXMLDocument extends POIXMLDocumentPart implements Close
         //save extended and custom properties
         getProperties().commit();
 
-        getPackage().save(stream);
+        OPCPackage pkg = getPackage();
+        if(pkg == null) {
+            throw new IOException("Cannot write data, document seems to have been closed already");
+        }
+        pkg.save(stream);
     }
 }

src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFWorkbook.java

@@ -1090,4 +1090,21 @@ public final class TestXSSFWorkbook extends BaseTestXWorkbook {
         //wb = new XSSFWorkbook(OPCPackage.open(file));
         //assertCloseDoesNotModifyFile(filename, wb);
     }
+
+	@Test
+	public void testCloseBeforeWrite() throws IOException {
+		Workbook wb = new XSSFWorkbook();
+		wb.createSheet("somesheet");
+
+		// test what happens if we close the Workbook before we write it out
+		wb.close();
+
+		try {
+			XSSFTestDataSamples.writeOutAndReadBack(wb);
+			fail("Expecting IOException here");
+		} catch (RuntimeException e) {
+			// expected here
+			assertTrue("Had: " + e.getCause(), e.getCause() instanceof IOException);
+		}
+	}
 }