fix bug 32805

cell/model/WorkbookElems.js

@@ -5590,6 +5590,12 @@ Filters.prototype.init = function(obj) {
 		if(obj.values[i].visible)
 		{
 			if(obj.values[i].isDateFormat)
+			{
+				if(obj.values[i].text === "")
+				{
+					this.Blank = true;
+				}
+				else
 				{
 					var dateGroupItem = new DateGroupItem();
 					var autoFilterDateElem = new AutoFilterDateElem(obj.values[i].val, obj.values[i].val, 1);
@@ -5598,6 +5604,7 @@ Filters.prototype.init = function(obj) {
 					
 					this.Dates.push(autoFilterDateElem);
 				}
+			}
 			else
 			{
 				if(obj.values[i].text === "")
@@ -5618,7 +5625,16 @@ Filters.prototype.isHideValue = function(val, isDateTimeFormat) {
 	var res = false;
 	
 	if(isDateTimeFormat && this.Dates)
+	{
+		if(val === "")
+		{
+			res = !this.Blank ? true : false;
+		}
+		else
+		{
 			res = this.binarySearch(val, this.Dates) !== -1 ? false : true;
+		}
+	}
 	else if(this.Values)
 	{
 		if(val === "")
@@ -5626,8 +5642,10 @@ Filters.prototype.isHideValue = function(val, isDateTimeFormat) {
 			res = !this.Blank ? true : false;
 		}
 		else
+		{
 			res = !this.lowerCaseValues[val] ? true : false;
 		}
+	}
 	
 	return res;
 };