From 58218c1d2702cdda3020193e039236e982e35462 Mon Sep 17 00:00:00 2001
From: Karl Nilsson <kjnilsson@gmail.com>
Date: Tue, 5 Sep 2023 14:13:21 +0100
Subject: [PATCH] ensure term is updated for snapshot installations

---
 src/ra_server.erl | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/src/ra_server.erl b/src/ra_server.erl
index 0695a2e8..e69bb923 100644
--- a/src/ra_server.erl
+++ b/src/ra_server.erl
@@ -1136,15 +1136,14 @@ handle_follower(#request_vote_rpc{term = Term, candidate_id = Cand,
                   [LogId, Cand, {LLIdx, LLTerm}, Term, CurTerm]),
             Reply = #request_vote_result{term = Term, vote_granted = true},
             State = update_term_and_voted_for(Term, Cand, State1),
-            {follower, State#{voted_for => Cand, current_term => Term},
-             [{reply, Reply}]};
+            {follower, State, [{reply, Reply}]};
         false ->
             ?INFO("~ts: declining vote for ~w for term ~b,"
                   " candidate last log index term was: ~w~n"
                   " last log entry idxterm seen was: ~w",
                   [LogId, Cand, Term, {LLIdx, LLTerm}, {LastIdxTerm}]),
             Reply = #request_vote_result{term = Term, vote_granted = false},
-            {follower, State1#{current_term => Term}, [{reply, Reply}]}
+            {follower, update_term(Term, State1), [{reply, Reply}]}
     end;
 handle_follower(#request_vote_rpc{term = Term, candidate_id = Candidate},
                 State = #{current_term := CurTerm,
@@ -1196,8 +1195,8 @@ handle_follower(#install_snapshot_rpc{term = Term,
     SnapState0 = ra_log:snapshot_state(Log0),
     {ok, SS} = ra_snapshot:begin_accept(Meta, SnapState0),
     Log = ra_log:set_snapshot_state(SS, Log0),
-    {receive_snapshot, State0#{log => Log,
-                               leader_id => LeaderId},
+    {receive_snapshot, update_term(Term, State0#{log => Log,
+                                                 leader_id => LeaderId}),
      [{next_event, Rpc}, {record_leader_msg, LeaderId}]};
 handle_follower(#request_vote_result{}, State) ->
     %% handle to avoid logging as unhandled
@@ -1269,19 +1268,19 @@ handle_receive_snapshot(#install_snapshot_rpc{term = Term,
                   end,
 
             {#{cluster := ClusterIds}, MacState} = ra_log:recover_snapshot(Log),
-            State = State0#{cfg => Cfg,
-                            log => Log,
-                            current_term => Term,
-                            commit_index => SnapIndex,
-                            last_applied => SnapIndex,
-                            cluster => make_cluster(Id, ClusterIds),
-                            machine_state => MacState},
+            State = update_term(Term,
+                                State0#{cfg => Cfg,
+                                        log => Log,
+                                        commit_index => SnapIndex,
+                                        last_applied => SnapIndex,
+                                        cluster => make_cluster(Id, ClusterIds),
+                                        machine_state => MacState}),
             %% it was the last snapshot chunk so we can revert back to
             %% follower status
             {follower, persist_last_applied(State), [{reply, Reply} | Effs]};
         next ->
             Log = ra_log:set_snapshot_state(SnapState, Log0),
-            State = State0#{log => Log},
+            State = update_term(Term, State0#{log => Log}),
             {receive_snapshot, State, [{reply, Reply}]}
     end;
 handle_receive_snapshot({ra_log_event, Evt},