I worked through some of the websites listed in the google-ima shim
script issue[1], to see what was going wrong. It turned out the
addEventListener method supports an optional context Object, which is
bound to the listener if provided. Some websites make use of that,
and then break when `this` is not bound correctly when events are
dispatched.
See also https://github.com/duckduckgo/tracker-surrogates/pull/24
1 - https://github.com/uBlockOrigin/uBlock-issues/issues/2265
Essentially a complement of `trusted-prune-inbound-object.js` added in
1c9da227d7
To perform object pruning on any object returned synchronously by
any given call.
The arguments for `trusted-prune-outbound-object` in order are:
- The name of the property to trap. Must be a function, and must
exist when the scriptlet tries to install the trap.
- The properties to prune (as with `json-prune`)
- The properties which must all be present for pruning to occur
(as with `json-prune`)
The scriptlets `json-prune.js` and `evaldata-prune.js` essentially
perform the same function, and will eventually be rewritten to
internally delegate to generic `trusted-prune-outbound-object.js`.
Related discussion:
https://github.com/uBlockOrigin/uBlock-issues/discussions/2895
Changes:
The _content of the My filters_ pane is now considered untrusted by
default, and only uBO's own lists are now trusted by default.
It has been observed that too many people will readily copy-paste
filters from random sources. Copy-pasting filters which require trust
represents a security risk to users with no understanding of how the
filters work and their potential abuse.
Using a filter which requires trust in a filter list from an untrusted
source will cause the filter to be invalid, i.e. shown as an error.
A new advanced setting has been added to control which lists are
considered trustworthy: `trustedListPrefixes`, which is a space-
separated list of tokens. Examples of possible values:
- `ublock-`: trust only uBO lists, exclude everything else including
content of _My filters_ (default value)
- `ublock- user-`: trust uBO lists and content of _My filters_
- `-`: trust no list, essentially disabling all filters requiring
trust (admins or people who don't trust us may want to use this)
One can also decide to trust lists maintained elsewhere. For example,
for stock AdGuard lists add ` adguard-`. To trust stock EasyList lists,
add ` easylist-`.
To trust a specific regional stock list, look-up its token in
assets.json and add to `trustedListPrefixes`.
The matching is made with String.startsWith(), hence why `ublock-`
matches all uBO's own filter lists.
This also allows to trust imported lists, for example add
` https://filters.adtidy.org/extension/ublock/filters/` to trust all
non-stock AdGuard lists.
Add the complete URL of a given imported list to trust only that one
list.
URLs not starting with `https://` or `file:///` will be rejected,
i.e. `http://example.org` will be ignored.
Invalid URLs are rejected.
Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/2896
TODO: Eventually, distinguish between filtering profile increasing
or decreasing so as to avoid flushing caches when increasing
filtering, which should not affect the scriptlets cache.
As per discussion with filter list maintainers.
To perform object pruning for any given call which has an object
as argument (hence "inbound").
Since `json-prune-stringify` scriptlet is a specific form of
pruning inbound objects, it has been removed.
The arguments for `trusted-prune-inbound-object` in order are:
- The name of the property to trap. Must be a function, and must
exist when the scriptlet tries to install the trap.
- The position of the object to prune in the argument list when
the trapped function is called. The position is 1-based and
must be an integer greater than 0.
- The properties to prune (as with `json-prune`)
- The properties which must all be present for pruning to occur
(as with `json-prune`)
- Varargs:
- `, dontOverwrite, 1`: do not modify the target inbound object
Examples:
Remove `title` and `name` properties before passing the object to
`JSON.stringify` call:
example.org##+js(trusted-prune-inbound-object, JSON.stringify, 1, title name)
Remove `status` property before passing the object to `Object.keys`
call but do not modify caller's instance of the object:
example.org##+js(trusted-prune-inbound-object, Object.keys, 1, status, , dontOverwrite, 1)
When the target world of a scriptlet is the ISOLATED one,
skip Blob-based injection in Firefox, as the current world
is always the ISOLATED one. This should make ISOLATED
world-based scriptlets more reliable (i.e. execute sooner)
in Firefox.
Raymond Hill