This closes qax-os#1942, fix percent sign missing in formatted result for zero numeric cell value (qax-os#1947)

- Updated unit tests

Author: samkeke

numfmt.go

@@ -4799,10 +4799,8 @@ func format(value, numFmt string, date1904 bool, cellType CellType, opts *Option
 			switch section.Type {
 			case nfp.TokenSectionPositive:
 				return nf.alignmentHandler(nf.positiveHandler())
-			case nfp.TokenSectionNegative:
-				return nf.alignmentHandler(nf.negativeHandler())
 			default:
-				return nf.alignmentHandler(nf.zeroHandler())
+				return nf.alignmentHandler(nf.negativeHandler())
 			}
 		}
 		return nf.alignmentHandler(nf.textHandler())
@@ -7108,11 +7106,6 @@ func (nf *numberFormat) negativeHandler() (result string) {
 	return nf.numberHandler()
 }
 
-// zeroHandler will be handling zero selection for a number format expression.
-func (nf *numberFormat) zeroHandler() string {
-	return nf.value
-}
-
 // textHandler will be handling text selection for a number format expression.
 func (nf *numberFormat) textHandler() (result string) {
 	for _, token := range nf.section[nf.sectionIdx].Items {
@@ -7137,21 +7130,18 @@ func (nf *numberFormat) getValueSectionType(value string) (float64, string) {
 		return 0, nfp.TokenSectionText
 	}
 	number, _ := strconv.ParseFloat(value, 64)
-	if number > 0 {
+	if number >= 0 {
 		return number, nfp.TokenSectionPositive
 	}
-	if number < 0 {
-		var hasNeg bool
-		for _, sec := range nf.section {
-			if sec.Type == nfp.TokenSectionNegative {
-				hasNeg = true
-			}
-		}
-		if !hasNeg {
-			nf.usePositive = true
-			return number, nfp.TokenSectionPositive
+	var hasNeg bool
+	for _, sec := range nf.section {
+		if sec.Type == nfp.TokenSectionNegative {
+			hasNeg = true
 		}
-		return number, nfp.TokenSectionNegative
 	}
-	return number, nfp.TokenSectionZero
+	if !hasNeg {
+		nf.usePositive = true
+		return number, nfp.TokenSectionPositive
+	}
+	return number, nfp.TokenSectionNegative
 }

numfmt_test.go

@@ -69,7 +69,10 @@ func TestNumFmt(t *testing.T) {
 		{"0.97952546296296295", "h:m", "23:30"},
 		{"43528", "mmmm", "March"},
 		{"43528", "dddd", "Monday"},
-		{"0", ";;;", "0"},
+		{"0", ";;;", ""},
+		{"0", "0%", "0%"},
+		{"0", "0.0%", "0.0%"},
+		{"0", "0.00%", "0.00%"},
 		{"43528", "[$-409]MM/DD/YYYY", "03/04/2019"},
 		{"43528", "[$-409]MM/DD/YYYY am/pm", "03/04/2019 AM"},
 		{"43528", "[$-111]MM/DD/YYYY", "43528"},