access: a limit that meets none of the user's capabilities gives nothing to look with

Looking at a node (its figures, peers, dashboard: Need::Observe) takes
any capability, a token's limit applied. Caps::is_empty is now true where
no capability of the user meets one of the limit's (Capability::meet), as
well as where there are none: a token limited to the member list, for a
user who may only read data/eu, may not look.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/access/mod.rs b/src/access/mod.rs
index ad50c72..cc6b7a2 100644
--- a/src/access/mod.rs
+++ b/src/access/mod.rs
@@ -197,8 +197,16 @@ impl Caps {
         self.limit.is_some()
     }
 
+    /// Whether they give nothing: none at all, or none that a token's limit meets
+    /// somewhere (`Capability::meet`).
     pub(crate) fn is_empty(&self) -> bool {
-        self.caps.is_empty() || self.limit.as_ref().is_some_and(Vec::is_empty)
+        match &self.limit {
+            None => self.caps.is_empty(),
+            Some(limit) => !self
+                .caps
+                .iter()
+                .any(|cap| limit.iter().any(|outer| cap.meet(outer).is_some())),
+        }
     }
 }