@dinatih commented on May 2, 2018, 5:08 PM UTC:
bootstrap-select version : v1.13.1
Optgroup labels are escaped (ex: '&' is escaped to & ) and it is not the case on option text.
trouble line is 1162 because it use htmlEscape(label).
https://plnkr.co/edit/PWJVWdryHXJ2mPh1QATK?p=preview
This issue was moved by caseyjhol from snapappointments/bootstrap-select-temp#51.
Released in v1.13.2!
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Released in v1.13.2!