fix regression related to #12504

Cloning date instances passed from state to cal panel as they appear to be mutating

Change-Id: I3775b8445ddc0a779b894b4e044bde93f4c5936c

client/src/com/vaadin/client/ui/VCalendarPanel.java

@@ -56,6 +56,7 @@ import com.vaadin.client.DateTimeService;
 import com.vaadin.client.Util;
 import com.vaadin.client.VConsole;
 import com.vaadin.shared.ui.datefield.Resolution;
+import com.vaadin.shared.util.SharedUtil;
 
 @SuppressWarnings("deprecation")
 public class VCalendarPanel extends FocusableFlexTable implements
@@ -2214,9 +2215,9 @@ public class VCalendarPanel extends FocusableFlexTable implements
      * @param startDate
      *            - the allowed range's start date
      */
-    public void setRangeStart(Date rangeStart) {
-        if (this.rangeStart != rangeStart) {
-            this.rangeStart = rangeStart;
+    public void setRangeStart(Date newRangeStart) {
+        if (!SharedUtil.equals(rangeStart, newRangeStart)) {
+            rangeStart = newRangeStart;
             if (initialRenderDone) {
                 // Dynamic updates to the range needs to render the calendar to
                 // update the element stylenames
@@ -2233,9 +2234,9 @@ public class VCalendarPanel extends FocusableFlexTable implements
      * @param endDate
      *            - the allowed range's end date
      */
-    public void setRangeEnd(Date rangeEnd) {
-        if (this.rangeEnd != rangeEnd) {
-            this.rangeEnd = rangeEnd;
+    public void setRangeEnd(Date newRangeEnd) {
+        if (!SharedUtil.equals(rangeEnd, newRangeEnd)) {
+            rangeEnd = newRangeEnd;
             if (initialRenderDone) {
                 // Dynamic updates to the range needs to render the calendar to
                 // update the element stylenames

client/src/com/vaadin/client/ui/datefield/PopupDateFieldConnector.java

@@ -178,8 +178,8 @@ public class PopupDateFieldConnector extends TextualDateConnector {
     public void onStateChanged(StateChangeEvent stateChangeEvent) {
         super.onStateChanged(stateChangeEvent);
         getWidget().setTextFieldEnabled(getState().textFieldEnabled);
-        getWidget().setRangeStart(getState().rangeStart);
-        getWidget().setRangeEnd(getState().rangeEnd);
+        getWidget().setRangeStart((Date) getState().rangeStart.clone());
+        getWidget().setRangeEnd((Date) getState().rangeEnd.clone());
     }
 
     @Override