Admin foreign key widgets don't quote keys.

[Joshua Goodwin]

In django.contrib.admin.ModelAdmin, _changeform_view, _delete_view and history_view and do unquote(object_id):

​https://github.com/django/django/blob/917fd9d03fdd21538864af4b412ac30b36d99268/django/contrib/admin/options.py#L1537

However, ForeignKeyRawIdWidget and RelatedFieldWidgetWrapper create links to this view without calling quote():

​https://github.com/django/django/blob/89a2216486fa8a0513cbb1d49d2d587d4116c60b/django/contrib/admin/widgets.py#L191

Steps to reproduce:

1. Create two models: Topping with a CharField primary key, and Pizza with a ForeignKey to Topping. Register both models with the admin site.
2. Create a Topping with the primary key '_40', and a Pizza with that topping
3. In the admin site, go the the /change/ page for the Pizza, and click on the 'change' icon for the Topping foreign key, or (if using ForeignKeyRawIdWidget) the link to the Topping '_40'.
4. See message 'Topping with ID "@" doesn't exist. Perhaps it was deleted?'.

[felixxm]

Reproduced at 25b5eea8cdc69a353bb2d22ea2012b09df6c62e4.

[zeynel]

I believe there are two main parts to handle to fix this bug.

• Quoting obj.pk value on ​https://github.com/django/django/blob/89a2216486fa8a0513cbb1d49d2d587d4116c60b/django/contrib/admin/widgets.py#L191
• Quoting object pk(or sending quoted values in context) on client side when user changes the selection on RelatedFieldWidget ​https://github.com/django/django/blob/89a2216486fa8a0513cbb1d49d2d587d4116c60b/django/contrib/admin/static/admin/js/admin/RelatedObjectLookups.js#L69

[felixxm]

I still have some issue when saving models, please check attached project and try to add a new pizza with e.g. _40 topping on admin/test_one/pizza/add/.