bug 57423: add unit test demonstrating corrupted workbook where CTRow xmlbeans are not in ascending order in the CTWorksheet; unit test adapted from Luca

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1817975 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -342,4 +342,42 @@ public final class TestUnfixedBugs {
        assertEquals("Did not have expected contents at rownum " + rowNum, 
                contents + ".0", cell.toString());
    }
+
+    @Test
+    public void bug57423_shiftRowsByLargeOffset() throws IOException {
+        try (
+            XSSFWorkbook wb = new XSSFWorkbook();
+            //OutputStream out = new FileOutputStream("/tmp/57423." + wb.getClass().getName() + ".xlsx"));
+        ) {
+            Sheet sh = wb.createSheet();
+            sh.createRow(0).createCell(0).setCellValue("a");
+            sh.createRow(1).createCell(0).setCellValue("b");
+            sh.createRow(2).createCell(0).setCellValue("c");
+            sh.shiftRows(0, 1, 3);
+
+            XSSFWorkbook wbBack = XSSFTestDataSamples.writeOutAndReadBack(wb);
+
+            assertThatRowsInAscendingOrder(wb);
+            assertThatRowsInAscendingOrder(wbBack);
+
+            //wbBack.write(out);
+            // Excel reports that the workbook is corrupt because the rows are not in ascending order
+            // LibreOffice doesn't complain when rows are not in ascending order
+
+            wbBack.close();
+        }
+    }
+
+    private void assertThatRowsInAscendingOrder(final XSSFWorkbook wb) {
+        // Check that CTRows are stored in ascending order of row index
+        long maxSeenRowNum = 0; //1-based
+        for (final CTRow ctRow : wb.getSheetAt(0).getCTWorksheet().getSheetData().getRowArray()) {
+            final long rowNum = ctRow.getR(); //1-based
+            //final int rowNum = Integer.parseInt(ctRow.getR()); //1-based
+            assertTrue("Row " + rowNum + " (1-based) is not in ascending order; previously saw " + maxSeenRowNum,
+                       rowNum > maxSeenRowNum);
+            maxSeenRowNum = rowNum;
+        }
+    }
+
 }