fix: Bubble up errors from Crypto::confirm_version (#2511)

I don't think they should have been suppressed.

Author: larseggert

neqo-transport/src/connection/mod.rs

@@ -2833,12 +2833,13 @@ impl Connection {
         }
     }
 
-    fn confirm_version(&mut self, v: Version) {
+    fn confirm_version(&mut self, v: Version) -> Res<()> {
         if self.version != v {
             qdebug!("[{self}] Compatible upgrade {:?} ==> {v:?}", self.version);
         }
-        self.crypto.confirm_version(v);
+        self.crypto.confirm_version(v)?;
         self.version = v;
+        Ok(())
     }
 
     fn compatible_upgrade(&mut self, packet_version: Version) -> Res<()> {
@@ -2847,15 +2848,15 @@ impl Connection {
         }
 
         if self.role == Role::Client {
-            self.confirm_version(packet_version);
+            self.confirm_version(packet_version)?;
         } else if self.tps.borrow().remote.is_some() {
             let version = self.tps.borrow().version();
             let dcid = self
                 .original_destination_cid
                 .as_ref()
                 .ok_or(Error::ProtocolViolation)?;
             self.crypto.states.init_server(version, dcid)?;
-            self.confirm_version(version);
+            self.confirm_version(version)?;
         }
         Ok(())
     }

neqo-transport/src/crypto.rs

@@ -242,9 +242,10 @@ impl Crypto {
     }
 
     /// Lock in a compatible upgrade.
-    pub fn confirm_version(&mut self, confirmed: Version) {
-        _ = self.states.confirm_version(self.version, confirmed);
+    pub fn confirm_version(&mut self, confirmed: Version) -> Res<()> {
+        self.states.confirm_version(self.version, confirmed)?;
         self.version = confirmed;
+        Ok(())
     }
 
     /// Returns true if new handshake keys were installed.