Merge pull request #1444 from geronimol/date-picker-cancel-behavior

fix: DateTime Picker "cancel" button behavior fix

Author: deandreamatias

lib/src/fields/form_builder_date_time_picker.dart

@@ -307,7 +307,11 @@ class _FormBuilderDateTimePickerState extends FormBuilderFieldDecorationState<
         if (date != null) {
           if (!mounted) break;
           final time = await _showTimePicker(currentValue);
-          newValue = combine(date, time);
+          if (time == null) {
+            newValue = null;
+          } else {
+            newValue = combine(date, time);
+          }
         }
         break;
     }
@@ -360,7 +364,7 @@ class _FormBuilderDateTimePickerState extends FormBuilderFieldDecorationState<
       };
     }
 
-    final timePickerResult = await showTimePicker(
+    return await showTimePicker(
       context: context,
       initialTime: currentValue != null
           ? TimeOfDay.fromDateTime(currentValue)
@@ -377,8 +381,6 @@ class _FormBuilderDateTimePickerState extends FormBuilderFieldDecorationState<
       onEntryModeChanged: widget.onEntryModeChanged,
       barrierDismissible: widget.barrierDismissible,
     );
-    return timePickerResult ??
-        (currentValue != null ? TimeOfDay.fromDateTime(currentValue) : null);
   }
 
   /// Sets the hour and minute of a [DateTime] from a [TimeOfDay].