Handle incomplete network identity fetching consistently (#7703)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: maxtropets <16566519+maxtropets@users.noreply.github.com>
Co-authored-by: Amaury Chamayou <amchamay@microsoft.com>

Author: 3 people

include/ccf/network_identity_interface.h

@@ -50,8 +50,10 @@ namespace ccf
     [[nodiscard]] virtual FetchStatus endorsements_fetching_status() const = 0;
 
     /// Returns the COSE endorsements chain for the given sequence number,
-    /// or std::nullopt if endorsement fetching has not completed or the
-    /// chain is not available for the given sequence number.
+    /// or std::nullopt if the chain is not available for the given sequence
+    /// number.
+    ///
+    /// @throws std::logic_error if endorsement fetching has not completed.
     [[nodiscard]] virtual std::optional<CoseEndorsementsChain>
     get_cose_endorsements_chain(ccf::SeqNo seqno) const = 0;
 

src/node/rpc/network_identity_subsystem.h

@@ -142,11 +142,12 @@ namespace ccf
     [[nodiscard]] std::optional<CoseEndorsementsChain>
     get_cose_endorsements_chain(ccf::SeqNo seqno) const override
     {
-      // All other cases must be handled after recovery has been completed and
-      // identities have been successfully fetched.
       if (fetch_status.load() != FetchStatus::Done)
       {
-        return std::nullopt;
+        throw std::logic_error(fmt::format(
+          "COSE endorsements chain requested for seqno {} but endorsement "
+          "fetching has not been completed yet",
+          seqno));
       }
 
       if (!current_service_from.has_value())