Datepicker: changed setDate not to modify the passed date argument. Fixes #6671 - setDate manipulates its argument

Author: pheiberg

tests/unit/datepicker/datepicker_options.js

@@ -470,6 +470,10 @@ test('setDate', function() {
 	equalsDate(inp.datepicker('getDate'), minDate, 'Set date min/max - setDate < min');
 	inp.datepicker('setDate', date2);
 	equalsDate(inp.datepicker('getDate'), maxDate, 'Set date min/max - setDate > max');
+	var dateAndTimeToSet = new Date(2008, 3 - 1, 28, 1, 11, 0);
+	var dateAndTimeClone = new Date(2008, 3 - 1, 28, 1, 11, 0);
+	inp.datepicker('setDate', dateAndTimeToSet);
+	equals(dateAndTimeToSet.getTime(), dateAndTimeClone.getTime(), 'Date object passed should not be changed by setDate');
 });
 
 test('altField', function() {

ui/jquery.ui.datepicker.js

@@ -1315,16 +1315,16 @@ $.extend(Datepicker.prototype, {
 			}
 			return new Date(year, month, day);
 		};
-		date = (date == null ? defaultDate : (typeof date == 'string' ? offsetString(date) :
-			(typeof date == 'number' ? (isNaN(date) ? defaultDate : offsetNumeric(date)) : date)));
-		date = (date && date.toString() == 'Invalid Date' ? defaultDate : date);
-		if (date) {
-			date.setHours(0);
-			date.setMinutes(0);
-			date.setSeconds(0);
-			date.setMilliseconds(0);
+		var newDate = (date == null ? defaultDate : (typeof date == 'string' ? offsetString(date) :
+			(typeof date == 'number' ? (isNaN(date) ? defaultDate : offsetNumeric(date)) : new Date(date.getTime()))));
+		newDate = (newDate && newDate.toString() == 'Invalid Date' ? defaultDate : newDate);
+		if (newDate) {
+			newDate.setHours(0);
+			newDate.setMinutes(0);
+			newDate.setSeconds(0);
+			newDate.setMilliseconds(0);
 		}
-		return this._daylightSavingAdjust(date);
+		return this._daylightSavingAdjust(newDate);
 	},
 
 	/* Handle switch to/from daylight saving.
@@ -1344,10 +1344,10 @@ $.extend(Datepicker.prototype, {
 		var clear = !(date);
 		var origMonth = inst.selectedMonth;
 		var origYear = inst.selectedYear;
-		date = this._restrictMinMax(inst, this._determineDate(inst, date, new Date()));
-		inst.selectedDay = inst.currentDay = date.getDate();
-		inst.drawMonth = inst.selectedMonth = inst.currentMonth = date.getMonth();
-		inst.drawYear = inst.selectedYear = inst.currentYear = date.getFullYear();
+		var newDate = this._restrictMinMax(inst, this._determineDate(inst, date, new Date()));
+		inst.selectedDay = inst.currentDay = newDate.getDate();
+		inst.drawMonth = inst.selectedMonth = inst.currentMonth = newDate.getMonth();
+		inst.drawYear = inst.selectedYear = inst.currentYear = newDate.getFullYear();
 		if ((origMonth != inst.selectedMonth || origYear != inst.selectedYear) && !noChange)
 			this._notifyChange(inst);
 		this._adjustInstDate(inst);
@@ -1625,9 +1625,9 @@ $.extend(Datepicker.prototype, {
 	_restrictMinMax: function(inst, date) {
 		var minDate = this._getMinMaxDate(inst, 'min');
 		var maxDate = this._getMinMaxDate(inst, 'max');
-		date = (minDate && date < minDate ? minDate : date);
-		date = (maxDate && date > maxDate ? maxDate : date);
-		return date;
+		var newDate = (minDate && date < minDate ? minDate : date);
+		newDate = (maxDate && newDate > maxDate ? maxDate : newDate);
+		return newDate;
 	},
 
 	/* Notify change of month/year. */