rewrite shared formula shifting code (#253)

* rewrite shared formula shifting code

* add test

Author: pjfanning

src/main/java/com/github/pjfanning/xlsx/impl/StreamingRowIterator.java

@@ -13,7 +13,6 @@
 import org.apache.poi.ss.SpreadsheetVersion;
 import org.apache.poi.ss.formula.FormulaParser;
 import org.apache.poi.ss.formula.FormulaRenderer;
-import org.apache.poi.ss.formula.FormulaShifter;
 import org.apache.poi.ss.formula.FormulaType;
 import org.apache.poi.ss.formula.ptg.Ptg;
 import org.apache.poi.ss.usermodel.*;
@@ -356,25 +355,27 @@ && isSpreadsheetTag(event.asEndElement().getName())) {
                 if (sf == null) {
                   LOG.warn("No SharedFormula found for si={}", formulaSI);
                 } else {
-                  CurrentRowEvaluationWorkbook evaluationWorkbook =
+                  final CurrentRowEvaluationWorkbook evaluationWorkbook =
                           new CurrentRowEvaluationWorkbook(wb, currentRow);
                   int sheetIndex = wb.getSheetIndex(sheet);
                   if (sheetIndex < 0) {
                     LOG.warn("Failed to find correct sheet index; defaulting to zero");
                     sheetIndex = 0;
                   }
                   try {
-                    Ptg[] ptgs = FormulaParser.parse(sf.getFormula(), evaluationWorkbook, FormulaType.CELL, sheetIndex, currentRow.getRowNum());
+                    Ptg[] ptgs = FormulaParser.parse(
+                        sf.getFormula(), evaluationWorkbook, FormulaType.CELL, sheetIndex, currentRow.getRowNum());
                     final int rowsToMove = currentRowNum - sf.getCellAddress().getRow();
-                    FormulaShifter formulaShifter = FormulaShifter.createForRowShift(sheetIndex, sheet.getSheetName(),
-                            0, SpreadsheetVersion.EXCEL2007.getLastRowIndex(), rowsToMove, SpreadsheetVersion.EXCEL2007);
-                    formulaShifter.adjustFormula(ptgs, sheetIndex);
+                    final int colsToMove = currentColNum - sf.getCellAddress().getColumn();
+                    org.apache.poi.ss.formula.SharedFormula formulaShifter = new org.apache.poi.ss.formula.SharedFormula(
+                            SpreadsheetVersion.EXCEL2007);
+                    ptgs = formulaShifter.convertSharedFormulas(ptgs, rowsToMove, colsToMove);
                     // There are some corner cases regarding formulas in this PR
                     // https://github.com/pjfanning/excel-streaming-reader/issues/151
                     String shiftedFmla = FormulaRenderer.toFormulaString(evaluationWorkbook, ptgs);
 
-                    LOG.debug("cell {} should have formula {} based on shared formula {} (rowsToMove={})",
-                            currentCell.getAddress(), shiftedFmla, sf.getFormula(), rowsToMove);
+                    LOG.debug("cell {} should have formula {} based on shared formula {} (rowsToMove={} colsToMove={})",
+                            currentCell.getAddress(), shiftedFmla, sf.getFormula(), rowsToMove, colsToMove);
                     currentCell.setFormula(shiftedFmla);
                   } catch (Exception e) {
                     LOG.warn("cell {} has a shared formula but excel-streaming-reader has an issue parsing it - will ignore the formula",

src/test/java/com/github/pjfanning/xlsx/StreamingReaderTest.java

@@ -1214,6 +1214,56 @@ public void testReadSharedFormulasEnabled() throws Exception {
     }
   }
 
+  @Test
+  public void testReadSharedFormulasIssue252() throws Exception {
+    // https://github.com/pjfanning/excel-streaming-reader/issues/252
+    try (
+        InputStream inputStream = new FileInputStream("src/test/resources/SharedFormula252.xlsx");
+        Workbook wb = StreamingReader.builder()
+            .setReadSharedFormulas(true)
+            .open(inputStream)
+    ) {
+      Sheet sheet = wb.getSheetAt(0);
+      Cell b11 = null;
+      Cell c11 = null;
+      Cell d11 = null;
+      Cell b23 = null;
+      Cell c23 = null;
+      Cell d23 = null;
+      for (Row row : sheet) {
+        if (row.getRowNum() == 10) {
+          b11 = row.getCell(1);
+          c11 = row.getCell(2);
+          d11 = row.getCell(3);
+        } else if (row.getRowNum() == 22) {
+          b23 = row.getCell(1);
+          c23 = row.getCell(2);
+          d23 = row.getCell(3);
+        }
+      }
+      assertNotNull("b11 found", b11);
+      assertNotNull("c11 found", c11);
+      assertNotNull("d11 found", d11);
+      assertNotNull("b23 found", b23);
+      assertNotNull("c23 found", c23);
+      assertNotNull("d23 found", d23);
+      assertEquals("SUM(B12:B20)", b11.getCellFormula());
+      assertEquals("SUM(C12:C20)", c11.getCellFormula());
+      assertEquals("SUM(D12:D20)", d11.getCellFormula());
+      assertEquals("B22+B11+B5+B21", b23.getCellFormula());
+      assertEquals("C22+C11+C5+C21", c23.getCellFormula());
+      assertEquals("D22+D11+D5+D21", d23.getCellFormula());
+      StreamingSheet ss = (StreamingSheet)sheet;
+      Map<String, SharedFormula> sharedFormulaMap = ss.getSharedFormulaMap();
+      assertEquals(2, sharedFormulaMap.size());
+      assertEquals("SUM(A12:A20)", sharedFormulaMap.get("0").getFormula());
+      assertEquals("A11", sharedFormulaMap.get("0").getCellAddress().formatAsString());
+      assertEquals("A22+A11+A5+A21", sharedFormulaMap.get("1").getFormula());
+      assertEquals("A23", sharedFormulaMap.get("1").getCellAddress().formatAsString());
+    }
+  }
+
+
   @Test
   public void testReadSharedFormulasSimple() throws Exception {
     try (