FileCommentPolicy::moderate() asked only whether somebody is staff and
holds moderate_comments. It never weighed the file the comment sits on,
and delete() returns true the moment moderate() does — so a client-scoped
moderator could delete any comment on the installation by naming its id.
Three call sites already knew this and wrote the boundary out by hand,
each with its own abort_unless($library->allowsFile(...), 403) after the
gate. The two that did not are FileCommentsController::destroy(), web and
API: both bind a comment directly, so nothing earlier in the request
establishes that the viewer may see its file.
The intent was documented in three places and enforced in none of them by
the policy — StaffLibraryScope says "the policies consult allowsFile() so
direct access respects the same boundary", VisibleCommentScope says "a
moderation screen is not a way around the visibility model". Put the rule
where those docblocks already say it lives.
moderate() now takes the comment when there is one. Named against the
class it still answers the coarser "does this user moderate at all",
which is what the queue's gate and the affordances ask. Membership is
tested by file id, so a file soft-deleted out from under its comments is
not in a scoped moderator's library either.
The author branch of delete() is deliberately untouched: deleting your
own words inside the edit window is not moderation, and a client is not
client-scoped in StaffLibraryScope's sense.
Approving through the API now derives its 403 from Gate::authorize rather
than the removed abort_unless, so the committed OpenAPI document gains
the shared AuthorizationException ref in place of an inline "An error"
schema — the shape nine of the other twelve documented 403s already use.
denkfabrik-li