"required=False" dones't work when use DateTimeField with SplitDateTimeWidget

[codeplayer]

in django shell, this bug can be reproduced like this:

In [1]: from django.forms import *

In [2]: class TForm(Form):
   ...:     d = DateTimeField(widget=SplitDateTimeWidget, required=False)
   ...: 

In [3]: print TForm(data={'d':''}).errors
<ul class="errorlist"><li>d<ul class="errorlist"><li>Enter a valid date/time.</li></ul></li></ul>

[Łukasz Rekucki]

Looks like a duplicate of #8898.

[Jacob]

Milestone 1.3 deleted