This closes #2384, fix GetStyle returning invalid style for fills without a pattern

- Upgrade the dependencies package version

Author: xuri

styles.go

@@ -1556,7 +1556,9 @@ func (f *File) extractGradientFill(gf *xlsxGradientFill, fill *Fill) {
 // settings by given pattern fill definition.
 func (f *File) extractPatternFill(pf *xlsxPatternFill, fill *Fill) {
 	fill.Type = "pattern"
-	fill.Pattern = inStrSlice(styleFillPatterns, pf.PatternType, false)
+	if pattern := inStrSlice(styleFillPatterns, pf.PatternType, false); pattern != -1 {
+		fill.Pattern = pattern
+	}
 	if pf.BgColor != nil && !pf.BgColor.Auto {
 		fill.Color = []string{f.getThemeColor(pf.BgColor)}
 	}

styles_test.go

@@ -936,4 +936,12 @@ func TestGetStyle(t *testing.T) {
 			assert.NoError(t, f.Close(), testCase.label)
 		}
 	})
+	t.Run("without_fill_pattern", func(t *testing.T) {
+		f := NewFile()
+		f.Styles = nil
+		f.Pkg.Store(defaultXMLPathStyles, fmt.Appendf(nil, `<styleSheet xmlns="%s"><fills count="1"><fill><patternFill/></fill></fills><cellXfs count="1"><xf fillId="0"></xf></cellXfs></styleSheet>`, NameSpaceSpreadSheet.Value))
+		style, err := f.GetStyle(0)
+		assert.NoError(t, err)
+		assert.Zero(t, style.Fill.Pattern)
+	})
 }