Fix file corrupted in some cases, check file extension and format code

Fix file corrupted when save as in XLAM / XLSM / XLTM / XLTX extension in some case
New exported error ErrWorkbookExt has been added, and check file extension on save the workbook
Format source code with `gofumpt`

1 files changed, 1 insertions, 1 deletions

diff --git a/rows.go b/rows.go
index 8702f93..88df52c 100644
--- a/rows.go
+++ b/rows.go
@@ -362,7 +362,7 @@ func (f *File) GetRowHeight(sheet string, row int) (float64, error) {
 	if row < 1 {
 		return defaultRowHeightPixels, newInvalidRowNumberError(row)
 	}
-	var ht = defaultRowHeight
+	ht := defaultRowHeight
 	ws, err := f.workSheetReader(sheet)
 	if err != nil {
 		return ht, err