Manage Stock only option available is Yes

Question

When I go to advanced inventory and want to set Manage Stock to No I only have the option Yes available. But why?

I have no idea where to start debugging any clue would be appreciated or maybe someone faced the same problem?

I already checked Stroes > Settings > Configuration > Catalog > Inventory settings and they look fine.

I don't know if it's related but how I found this bug was because a product I just created is apparently not salable and not listed in cataloginventory_stock_status table.

Update:
I figured out a bit more. The same problem affects Qty Uses Decimals too. In Magento_Ui/js/form/element/select::setOptions the following options are set for the selects Manage Stock, Qty Uses Decimals and Allow Multiple Boxes for Shipping:

this.optionsis set to the result of parseOptions() which gets data passed. In two of the cases the value 0 for label "No" is passed as integer and once as string. That's why parseOptions() will set the label to ' '.

The label is ' ' but the source code for the select then is <option data-title value="0"></option> can anyone explain this or has an idea why?
Does anyone know where the data for the options is passed to the select ui component?

Answer 1

Problem was completely on our side. We applied this core patch due to another issue we had. Problem with this patch is the simple compare ==. With a type compare === it works just fine again.

But I would be happy if someone could answer or update this answer to explain why sometimes the values are passed as strings and sometimes as integers.