This fix formula calculation accuracy issue and panic when set pane

- Fix `GROWTH` and `TREND` calculation accuracy issue
- Fix panic when add pane on empty sheet views worksheet
- New exported constants `MinFontSize`

Author: xuri

calc.go

@@ -4579,8 +4579,7 @@ func newFormulaArgMatrix(numMtx [][]float64) (arg [][]formulaArg) {
 	for r, row := range numMtx {
 		arg = append(arg, make([]formulaArg, len(row)))
 		for c, cell := range row {
-			decimal, _ := big.NewFloat(cell).SetPrec(15).Float64()
-			arg[r][c] = newNumberFormulaArg(decimal)
+			arg[r][c] = newNumberFormulaArg(cell)
 		}
 	}
 	return

calc_test.go

@@ -4518,17 +4518,17 @@ func TestCalcGROWTHandTREND(t *testing.T) {
 	formulaList := map[string]string{
 		"=GROWTH(A2:B2)":                    "1",
 		"=GROWTH(B2:B5,A2:A5,A8:A10)":       "160",
-		"=GROWTH(B2:B5,A2:A5,A8:A10,FALSE)": "467.84375",
+		"=GROWTH(B2:B5,A2:A5,A8:A10,FALSE)": "467.842838114059",
 		"=GROWTH(A4:A5,A2:B3,A8:A10,FALSE)": "",
 		"=GROWTH(A3:A5,A2:B4,A2:B3)":        "2",
 		"=GROWTH(A4:A5,A2:B3)":              "",
 		"=GROWTH(A2:B2,A2:B3)":              "",
-		"=GROWTH(A2:B2,A2:B3,A2:B3,FALSE)":  "1.28399658203125",
+		"=GROWTH(A2:B2,A2:B3,A2:B3,FALSE)":  "1.28402541668774",
 		"=GROWTH(A2:B2,A4:B5,A4:B5,FALSE)":  "1",
 		"=GROWTH(A3:C3,A2:C3,A2:B3)":        "2",
 		"=TREND(A2:B2)":                     "1",
 		"=TREND(B2:B5,A2:A5,A8:A10)":        "95",
-		"=TREND(B2:B5,A2:A5,A8:A10,FALSE)":  "81.66796875",
+		"=TREND(B2:B5,A2:A5,A8:A10,FALSE)":  "81.6666666666667",
 		"=TREND(A4:A5,A2:B3,A8:A10,FALSE)":  "",
 		"=TREND(A4:A5,A2:B3,A2:B3,FALSE)":   "1.5",
 		"=TREND(A3:A5,A2:B4,A2:B3)":         "2",

errors.go

@@ -102,7 +102,7 @@ var (
 	ErrMaxRows = errors.New("row number exceeds maximum limit")
 	// ErrMaxRowHeight defined the error message on receive an invalid row
 	// height.
-	ErrMaxRowHeight = errors.New("the height of the row must be smaller than or equal to 409 points")
+	ErrMaxRowHeight = fmt.Errorf("the height of the row must be smaller than or equal to %d points", MaxRowHeight)
 	// ErrImgExt defined the error message on receive an unsupported image
 	// extension.
 	ErrImgExt = errors.New("unsupported image extension")
@@ -145,9 +145,9 @@ var (
 	ErrCustomNumFmt = errors.New("custom number format can not be empty")
 	// ErrFontLength defined the error message on the length of the font
 	// family name overflow.
-	ErrFontLength = errors.New("the length of the font family name must be smaller than or equal to 31")
+	ErrFontLength = fmt.Errorf("the length of the font family name must be smaller than or equal to %d", MaxFontFamilyLength)
 	// ErrFontSize defined the error message on the size of the font is invalid.
-	ErrFontSize = errors.New("font size must be between 1 and 409 points")
+	ErrFontSize = fmt.Errorf("font size must be between %d and %d points", MinFontSize, MaxFontSize)
 	// ErrSheetIdx defined the error message on receive the invalid worksheet
 	// index.
 	ErrSheetIdx = errors.New("invalid worksheet index")
@@ -161,7 +161,7 @@ var (
 	ErrGroupSheets = errors.New("group worksheet must contain an active worksheet")
 	// ErrDataValidationFormulaLength defined the error message for receiving a
 	// data validation formula length that exceeds the limit.
-	ErrDataValidationFormulaLength = errors.New("data validation must be 0-255 characters")
+	ErrDataValidationFormulaLength = fmt.Errorf("data validation must be 0-%d characters", MaxFieldLength)
 	// ErrDataValidationRange defined the error message on set decimal range
 	// exceeds limit.
 	ErrDataValidationRange = errors.New("data validation range exceeds limit")

sheet.go

@@ -773,6 +773,9 @@ func (f *File) SetPanes(sheet, panes string) error {
 	if fs.Freeze {
 		p.State = "frozen"
 	}
+	if ws.SheetViews == nil {
+		ws.SheetViews = &xlsxSheetViews{SheetView: []xlsxSheetView{{}}}
+	}
 	ws.SheetViews.SheetView[len(ws.SheetViews.SheetView)-1].Pane = p
 	if !(fs.Freeze) && !(fs.Split) {
 		if len(ws.SheetViews.SheetView) > 0 {

sheet_test.go

@@ -104,6 +104,12 @@ func TestSetPane(t *testing.T) {
 	assert.NoError(t, f.SetPanes("Panes 4", ""))
 	assert.EqualError(t, f.SetPanes("SheetN", ""), "sheet SheetN is not exist")
 	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetPane.xlsx")))
+	// Test add pane on empty sheet views worksheet
+	f = NewFile()
+	f.checked = nil
+	f.Sheet.Delete("xl/worksheets/sheet1.xml")
+	f.Pkg.Store("xl/worksheets/sheet1.xml", []byte(`<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"><sheetData/></worksheet>`))
+	assert.NoError(t, f.SetPanes("Sheet1", `{"freeze":true,"split":false,"x_split":1,"y_split":0,"top_left_cell":"B1","active_pane":"topRight","panes":[{"sqref":"K16","active_cell":"K16","pane":"topRight"}]}`))
 }
 
 func TestPageLayoutOption(t *testing.T) {

styles.go

@@ -2042,7 +2042,7 @@ func (f *File) getFontID(styleSheet *xlsxStyleSheet, style *Style) (fontID int)
 // settings.
 func (f *File) newFont(style *Style) *xlsxFont {
 	fontUnderlineType := map[string]string{"single": "single", "double": "double"}
-	if style.Font.Size < 1 {
+	if style.Font.Size < MinFontSize {
 		style.Font.Size = 11
 	}
 	if style.Font.Color == "" {

xmlDrawing.go

@@ -107,6 +107,7 @@ const (
 	MaxFieldLength       = 255
 	MaxColumnWidth       = 255
 	MaxRowHeight         = 409
+	MinFontSize          = 1
 	TotalRows            = 1048576
 	TotalColumns         = 16384
 	TotalSheetHyperlinks = 65529