This is not a real bug, but it gives some problems as shown below.
on file:
dom\html\form\input\select\combo.php

on line 216:
IF I previously pass a "dataValue" using the jdomOptions AND my purpose is to set a value to a combo list field for a foreign key (the datakey is an integer), THEN when "$selected" value should be matched it still gives FALSE.

this is due to the PHP comparison operator "===", the variable type of $item->$listKey is recognized as string and it should be an integer.

I don't know if in this case the indentical comparison operator should be really used , in my opinion the simple equal operator could be enough, I leave to the admin further investigations.
In my case I just changed it to, and it doesn't give me any problems, until now:

Yes it is very important for filters for example.
Because 0 is different than ""

Suggestion :

Reformate the value using
'dataValue' => (int)$this->item->myfield //Parse to integer
...
or
'dataValue' => (string)$this->item->myfield //Parse to string


with dataValue you define the value directly.

Hope it helps.

thanks for the reply. I didn't think about that.
Yes, it's needed and thanks for the advice, you saved me to fix this probable bug later.
by the way I saw some of the attributes are not enabled yet on all the type fields, there is a specific reason for that, or it's just because you didn't use them yet?