List index out of range when reschedule a survey

[Atisom]

Describe the bug
When we want to reschedule a survey, we got this error: "List index out of range"

Debian GNU/Linux 9 \n \l
$ indico -v
Indico v2.3.1

To Reproduce
Steps to reproduce the behavior:

1. Go to https://$siteurl/event/1037/manage/surveys/672/
2. Click on 'Reschedule'
3. Set the end date to 31/12/2020
4. I got error message

Expected behavior
Reschedule the survey

Screenshots

Additional context
I got the error message:

{u'data': {u'get': {},
           u'headers': {'Accept': u'application/json, text/javascript, */*; q=0.01',
                        'Accept-Encoding': u'gzip, deflate, br',
                        'Accept-Language':
u'en-HU,en;q=0.9,hu-HU;q=0.8,hu;q=0.7,en-GB;q=0.6,en-US;q=0.5',
                        'Connection': u'keep-alive',
                        'Content-Length': u'101',
                        'Content-Type': u'application/x-www-form-urlencoded;
charset=UTF-8',
                        'Cookie': u'*****',
                        'Host': u'*****',
                        'Origin': u'*****',
                        'Referer':
u'*****',
                        'Sec-Fetch-Dest': u'empty',
                        'Sec-Fetch-Mode': u'cors',
                        'Sec-Fetch-Site': u'same-origin',
                        'User-Agent': u'*****',
                        'X-Csrf-Token': u'*****',
                        'X-Requested-With': u'XMLHttpRequest'},
           u'json': None,
           u'post': {'csrf_token': u'*****',
                     'end_dt': [u'01/12/2020', u'23:59'],
                     'start_dt': u'00:00'},
           u'url': {'confId': u'1037', 'survey_id': 672}},
 u'endpoint': u'surveys.schedule_survey',
 u'id': '63cdf57cc8a14986',
 u'ip': '*****',
 u'method': 'POST',
 u'referrer': '*****',
 u'rh': 'RHScheduleSurvey',
 u'time': '2020-11-29T18:57:10.461959',
 u'url': u'*****',
 u'user': {u'email': u'*****',
           u'id': 250,
           u'name': u'Attila Debreczeni'},
 u'user_agent': u'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML,
like Gecko) Chrome/87.0.4280.66 Safari/537.36'}

[ThiefMaster]

I'll have a look tomorrow. Good timing, I planned to release 2.3.2 during one of the next days anyway, so that fix will make it in there.

My guess it that it happens because no data gets submitted for a disabled field, and we don't handle that in the backend.

[ThiefMaster]

Fixed :)

If you need to hotfix it on your instance, apply the datetime_widget.html change manually; the rest is just to make things cleaner.

[Atisom]

Thank you, it works! :)