ZF-10958: addDisplayGroup creates input fields twice when using long id's (names)
If you create a Zend Form and add an Element with an id (name) like 'form_data_id234'. You can easily add this form to a displaygroup using addDisplayGroup().
But if your elements id is too long it will be added to the display group and remains in the "main" form too. (Outside of the desired display group.) So this element exists twice in a form. First it appears in the display group and also outside of the group but inside the form.
As the fields name is identical, this would raise a logical validation error... (You could never be sure which field value will be used as the correct input field value.)
Here are some example names which are too long and will appear twice in the form: _form_personDetail_communication_COM_4c808f1c19cb1831254439-element _form_personDetail_communication_COM_4c808f1c19cb1831254439-element
I stumbled upon this error afterI updated from 1.10.7 to 1.11.2. In 1.10.7 everythings works as expected.