toFormDataMap returns an empty map if the content type doesn't exactly match application/x-www-form-urlencoded
When making PUT requests with XMLHttpRequest, Firefox automatically tacks on a charset, yielding a content type of "application/x-www-form-urlencoded; charset=UTF-8", which prevents toFormDataMap from finding the parameters.
toFormDataMap returns an empty map if the content type doesn't exactly match application/x-www-form-urlencoded When making PUT requests with XMLHttpRequest, Firefox automatically tacks on a charset, yielding a content type of "application/x-www-form-urlencoded; charset=UTF-8", which prevents toFormDataMap from finding the parameters.