Agile boards have Days in Column value offset by a large incorrect amount

Summary

Agile boards have Days in Column value offset by a large incorrect amount

Steps to Reproduce

1. Create or use a project with an agile simplified workflow.
2. Ensure the Days in Column feature is enabled.
3. On the board, transition an issue to the same status it is currently in.
4. View Days in Column

Expected Results

The Days in Column value remains the same.

Actual Results

The Days in Column dots max out and mousing over displays a huge value (e.g. over 16k days).

Solution / Workaround

Transition the ticket to other status, and then back to the target column. Consider changing the workflow to prevent recursive transitions.

Notes/Details

".. days in column" data is based on opt_data.issue.timeInColumn.days value and is calculated the following way:

if (b.timeInColumn) {
b.timeInColumn.days = Math.floor((b.timeInColumn.durationPreviously + new Date().getTime() - b.timeInColumn.enteredStatus) / a)
}

which is calculated from timeInColumn value from JSON https://<JIRA>/rest/greenhopper/1.0/xboard/work/allData.json?rapidViewId=<BOARD_ID>.
Normally, this data looks like:

"timeInColumn": {
  "enteredStatus": 1442936354000,
  "durationPreviously": 0
},

in case of an issue was transitioned to the same status it is currently in:

"timeInColumn": {
  "enteredStatus": 0,
  "durationPreviously": 2301491000
},

which leads to large opt_data.issue.timeInColumn.days value