date and time fields in dialog: error when press esc to close a dialog when a date or time field has focus

[becky]

On tests/test_dialog.html open the dialog or tooltip dialog via the "Show Dialog" or "Show Tooltip Dialog" buttons. Put focus on the date or time field (either with the mouse or by tabbing to field). With focus on one of those two fields, press escape to close the dialog and you get an error: unterminated string literal.

[bill]

Same as #5202?

[bill]

Above comment should read "see also #5202". Failing for me (on IE) in _FormValueWidget::_onKeyPress() apparently since getValue() returns undefined rather than null, so you try to call toString()

[doughays]

(In [12165]) Fixes #5645 !strict. Made the default value for datetextbox undefined instead of NaN. Added a check for undefined before calling toString().