Some exposed variables (eg. `user_ip`) used in filters are sensitive
and need to only be available to restricted groups of users.
Back-end changes:
- Add `AbuseFilterProtectedVariables` which defines what variables are
protected by the new right `abusefilter-access-protected-vars`
- Add the concept of a `protected` variable, the use of which will
denote the entire filter as protected via a flag on `af_hidden`
New UX features:
- Display changes to the protected status of filters on history and diff
pages
- Check for protected variables and the right to see them in filter
validation and don't allow a filter to be saved if it uses a variable
that the user doesn't have access to
- Check for the right to view protected variables before allowing access
and edits to existing filters that use them
Bug: T364465
Bug: T363906
Change-Id: I828bbb4015e87040f69a8e10c7888273c4f24dd3
Protected variables will cause the filter using them to become
protected as well. `af_hidden` can be used to track this flag,
as it is a TINYINT and can be converted into a bitmask with no
schema changes.
This is not a backwards-compatible change, as now all checks must
check the `hidden` flag specifically or otherwise will be cast to
true if any flag is set.
To support this change:
- "hidden" is considered a flag set in the `af_hidden`. This is a
change in concept with no need for updates to the column values,
as there is currently only one flag in the bitmask.
- `Flag`s store the bitmask as well as the state of single flags
and can return either.
- Any checks against the `af_hidden` value no longer check a
boolean value and instead now check the `hidden` flag value.
Bug: T363906
Change-Id: I358205cb1119cf1e4004892c37e36e0c0a864f37
