Comment # 19 from Julian Maurice

Hmm... I'm quite sure there is a problem with some caching somewhere.
In patch, additem.js:60 contains:

        var field_elt = $("#" + index)
            .find("[name='kohafield'][value='items."+field+"']")
            .prevAll("[name='field_value']")[0];

(no 'node' variable here)
while in master, additem.js:60 is

        var origin = node.getElementsByTagName("select");

(here is the 'node'!)

Same for the document.getElementById which is not anymore in additem.js with
the patch

So, if it's not from your browser, maybe the server is caching static files.
If you want to check easily, additem.js with the patch starts with

        function addItem( node, unique_item_fields ) {

while in master it's:

        function deleteItemBlock(index) {

About the quantity, items are counted only after clicking on "Add" (and the
item is displayed in the items list/table). This is a behaviour change. You
should consider the item form as an 'Edit box' where changes are applied only
after clicking on 'Add' or 'Update'. And the items list/table is what will be
saved.