Fixed issue #809, losing rows from cellstore when moving backwards

sheet.go

@@ -30,8 +30,8 @@ type Sheet struct {
 	cellStore       CellStore
 	currentRow      *Row
 	cellStoreName   string // The first part of the key used in
-			       // the cellStore.  This name is stable,
-			       // unlike the Name, which can change
+	// the cellStore.  This name is stable,
+	// unlike the Name, which can change
 }
 
 // NewSheet constructs a Sheet with the default CellStore and returns
@@ -47,8 +47,8 @@ func NewSheetWithCellStore(name string, constructor CellStoreConstructor) (*Shee
 		return nil, fmt.Errorf("sheet name is invalid: %w", err)
 	}
 	sheet := &Sheet{
-		Name: name,
-		Cols: &ColStore{},
+		Name:          name,
+		Cols:          &ColStore{},
 		cellStoreName: name,
 	}
 	var err error
@@ -298,10 +298,15 @@ func (s *Sheet) maybeAddRow(rowCount int) {
 // Make sure we always have as many Rows as we do cells.
 func (s *Sheet) Row(idx int) (*Row, error) {
 	s.mustBeOpen()
+
 	s.maybeAddRow(idx + 1)
-	if s.currentRow != nil && idx == s.currentRow.num {
-		return s.currentRow, nil
+	if s.currentRow != nil {
+		if idx == s.currentRow.num {
+			return s.currentRow, nil
+		}
+		s.cellStore.WriteRow(s.currentRow)
 	}
+
 	r, err := s.cellStore.ReadRow(makeRowKey(s, idx), s)
 	if err != nil {
 		if _, ok := err.(*RowNotFoundError); !ok {
@@ -949,7 +954,6 @@ func handleNumFmtIdForXLSX(NumFmtId int, styles *xlsxStyleSheet) (XfId int) {
 	return
 }
 
-
 func IsSaneSheetName(sheetName string) error {
 	runeLength := utf8.RuneCountInString(sheetName)
 	if runeLength > 31 || runeLength == 0 {

sheet_test.go

@@ -737,6 +737,54 @@ func TestMakeXLSXSheet(t *testing.T) {
 	})
 }
 
+func TestIssue809(t *testing.T) {
+	c := qt.New(t)
+
+	csRunO(c, "Issue809", func(c *qt.C, option FileOption) {
+		outfile := filepath.Join(t.TempDir(), "bug809.xlsx")
+		f := NewFile(option)
+		sh, err := f.AddSheet("Sheet1")
+		c.Assert(err, qt.IsNil)
+
+		// Write Colors (y-axis).
+		colors := []string{"Red", "Green", "Blue"}
+		for i, clr := range colors {
+			cell, _ := sh.Cell(i+1, 0)
+			cell.SetString(clr)
+		}
+
+		// Write Numbers (x-axis).
+		numbers := []string{"1", "2", "3"}
+		for i, num := range numbers {
+			cell, _ := sh.Cell(0, i+1)
+			cell.SetString(num)
+		}
+
+		c.Assert(f.Save(outfile), qt.IsNil)
+
+		f = nil
+
+		f2, err := OpenFile(outfile, option)
+		c.Assert(err, qt.IsNil)
+
+		sh2, ok := f2.Sheet["Sheet1"]
+		c.Assert(ok, qt.IsTrue)
+
+		for i, clr := range colors {
+			cell, err := sh2.Cell(i+1, 0)
+			c.Assert(err, qt.IsNil)
+			t.Logf("%q == %q?\n", cell.String(), clr)
+			c.Assert(cell.String(), qt.Equals, clr)
+		}
+
+		for i, num := range numbers {
+			cell, err := sh2.Cell(0, i+1)
+			c.Assert(err, qt.IsNil)
+			c.Assert(cell.String(), qt.Equals, num)
+		}
+	})
+}
+
 func TestTemp(t *testing.T) {
 	c := qt.New(t)
 	option := UseDiskVCellStore
@@ -774,5 +822,4 @@ func TestTemp(t *testing.T) {
 	xSI := xSST.SI[0]
 	c.Assert(xSI.T.Text, qt.Equals, "A cell!")
 	c.Assert(xSI.R, qt.HasLen, 0)
-
 }