In some restricted setups all JS payloads need tight control.
This setting bans admins from making changes to JS on the site and
requires all themes be whitelisted to be used.
There are edge cases we still need to work through in this mode
hence this is still not supported in production and experimental.
Use an example like this to enable:
`DISCOURSE_WHITELISTED_THEME_REPOS="https://repo.com/repo.git,https://repo.com/repo2.git"`
By default this feature is not enabled and no changes are made.
One exception is that default theme id was missing a security check
this was added for correctness.
If `default email digest frequency` was set to "Never", users would get
a `digest_after_minutes` set to `nil` which triggered this error
in the logs if/when the site eventually changed that setting and
enabled digests:
```
NoMethodError (undefined method `>=' for nil:NilClass)
/var/www/discourse/app/mailers/user_notifications.rb:227:in `digest'
```
Previously the pull hotlinked images job was skipped after system edits. This ensured that we never had an infinite loop of system-edit/pull-hotlinked/system-edit/pull-hotlinked etc.
A side effect was that edits made by system for any other reason (e.g. API, removing full quotes) would prevent pulling hotlinked images. This commit removes the system edit check, and replaces it with another method to avoid an infinite job scheduling loop.
Hostname can vary per-site on a multisite cluster, so this change requires converting the compiler_version from a constant into a class method which is evaluated at runtime. The value is stored in the theme DistributedCache, so performance impact should be negligible.
We previously did not account for completely untagged topics when
looking at muted tags, this caused new/unread counts to be off if
1. You had muted tags
2. You had an unread/new topic
3. This topic had no tags
This feature allows certain plugins to output tag information
to topic tracking state, this allows per tag stats which can be
used by sidebars and other plugins that need per tag stats
Not enabled by default cause this would add cost to a critical
query
It might happen that some User records have no associated primary emails.
In which case we don't ever want to send them a digest.
Also added a new "user_email_no_email" skipped email log to ensure these cases
are properly handled and surfaced.
Previously we had a partial fix in place where non human users
were not allowed draft sequences, this left edges around where non
human users asked for drafts yet had none.
For example system could already have a few drafts in place.
This also removes and extensibility point we added that is not in use
