When placing multiple holds at once, the various selects for pickup location have a little X at the far right next to the dropdown arrow. Clicking the X clears the field and allows for holds to be created with null pickup locations. We discovered the hard way that things like the holds queue completely break when there are null pickup locations lurking about. It also seems to prevent the holds tab on the patron account from loading.
After a picking at this a little bit more, it seems the custom jQuery I'm using to prefill the pickup locations is facilitating the problem. If I disable the jQuery, the page pops up an alert and won't save with an empty pickup location. The X to clear that top pickup location select doesn't appear when placing a single-title hold so it might still make sense to get rid of it on the multi-hold page to match behaviors.
The x is part of the select2 pull downs, not sure if it can be removed.
The larger issue was that holds could be placed without branchcodes assigned under certain circumstances. If I'm understanding correctly, bug 31086 seems to fully prevent that from happening so this may not be a problem any longer.
(In reply to Jason Robb from comment #3) > The larger issue was that holds could be placed without branchcodes assigned > under certain circumstances. > > If I'm understanding correctly, bug 31086 seems to fully prevent that from > happening so this may not be a problem any longer. Marking as MOVED.