Depends on D19585. Ref T13164.
Almost all transactions require CAN_EDIT on the object, but they generally do not enforce this directly today. Instead, this is effectively enforced by Controllers, API methods, and EditEngine doing a CAN_EDIT check when loading the object to be edited.
A small number of transactions do not require CAN_EDIT, and instead require only a weaker/lesser permission. These are:
- Joining a project which you have CAN_JOIN on.
- Leaving a project which isn't locked.
- Joining a Conpherence thread you can see (today, no separate CAN_JOIN permission for Conpherence).
- Leaving a Conpherence thread.
- Unsubscribing.
- Using the special !history command from email.
Additionally, these require CAN_INTERACT, which is weaker than CAN_EDIT:
- Adding comments.
- Subscribing.
- Awarding tokens.
Soon, I want to add "disabling users" to this list, so that you can disable users if you have "Can Disable User" permission, even if you can not otherwise edit users.
It's possible this list isn't exhaustive, so this change might break something by adding a policy check to a place where we previously didn't have one. If so, we can go weaken that policy check to the appropriate level.
Enforcement of these special cases is currently weird:
- We mostly don't actually enforce CAN_EDIT in the Editor; instead, it's enforced before you get to the editor (in EditEngine/Controllers).
- To apply a weaker requirement (like leaving comments or leaving a project), we let you get through the Controller without CAN_EDIT, then apply the weaker policy check in the Editor.
- Some transactions apply a confusing/redundant explicit CAN_EDIT policy check. These mostly got cleaned up in previous changes.
Instead, the new world order is:
- Every transaction has capability/policy requirements.
- The default is CAN_EDIT, but transactions can weaken this explicitly they want.
- So now we'll get requirements right in the Editor, even if Controllers or API endpoints make a mistake.
- And you don't have to copy/paste a bunch of code to say "yes, every transaction should require CAN_EDIT".