This fix potential panic and file corrupted

- Fix the panic when set or get sheet view options on the sheet without views options
- Fix generated workbook corruption caused by empty created or modified dcterms in the document core properties
- Update the unit tests

1 files changed, 5 insertions, 0 deletions

diff --git a/sheetview.go b/sheetview.go
index bf8f023..99f0634 100644
--- a/sheetview.go
+++ b/sheetview.go
@@ -163,6 +163,11 @@ func (f *File) getSheetView(sheet string, viewIndex int) (*xlsxSheetView, error)
 	if err != nil {
 		return nil, err
 	}
+	if ws.SheetViews == nil {
+		ws.SheetViews = &xlsxSheetViews{
+			SheetView: []xlsxSheetView{{WorkbookViewID: 0}},
+		}
+	}
 	if viewIndex < 0 {
 		if viewIndex < -len(ws.SheetViews.SheetView) {
 			return nil, fmt.Errorf("view index %d out of range", viewIndex)