From 2b783c6126e7c774f949605570d6a6826c0e96e2 Mon Sep 17 00:00:00 2001
From: MorganaFuture <andrewmochalskyi@gmail.com>
Date: Sat, 4 Oct 2025 20:55:05 +0300
Subject: [PATCH] Fix crash when committing to deleted ETS table during member
 removal

Fixes race condition in issue #528 where removing and re-adding a
cluster member causes a crash in ra_mt:commit/1.
Wrap ets:insert/2 in catch block to gracefully handle
deleted tables. Return empty list instead of crashing.
---
 src/ra_mt.erl        | 13 +++++++++----
 test/ra_mt_SUITE.erl | 20 ++++++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/ra_mt.erl b/src/ra_mt.erl
index df25476e5..bfea116b2 100644
--- a/src/ra_mt.erl
+++ b/src/ra_mt.erl
@@ -155,10 +155,15 @@ commit(#?MODULE{tid = Tid,
                                  commit(Prev0)
                          end,
     Staged = lists:reverse(Staged0),
-    true = ets:insert(Tid, Staged),
-    %% TODO: mt: could prev contain overwritten entries?
-    {PrevStaged ++ Staged, State#?MODULE{staged = undefined,
-                                         prev = Prev}}.
+    case catch ets:insert(Tid, Staged) of
+        true ->
+            %% TODO: mt: could prev contain overwritten entries?
+            {PrevStaged ++ Staged, State#?MODULE{staged = undefined,
+                                                 prev = Prev}};
+        {'EXIT', {badarg, _}} ->
+            {[], State#?MODULE{staged = undefined,
+                               prev = Prev}}
+    end.
 
 -spec abort(state()) -> state().
 abort(#?MODULE{staged = undefined} = State) ->
diff --git a/test/ra_mt_SUITE.erl b/test/ra_mt_SUITE.erl
index 4aff51ef9..4ef057992 100644
--- a/test/ra_mt_SUITE.erl
+++ b/test/ra_mt_SUITE.erl
@@ -34,6 +34,7 @@ all_tests() ->
      stage_commit,
      range_overlap,
      stage_commit_abort,
+     commit_after_table_deleted,
      perf
     ].
 
@@ -468,6 +469,25 @@ perf(_Config) ->
 
     ok.
 
+commit_after_table_deleted(_Config) ->
+    Tid = ets:new(t1, [set, public]),
+    Mt0 = ra_mt:init(Tid),
+
+    %% Stage some entries
+    {ok, Mt1} = ra_mt:stage({1, 1, <<"data1">>}, Mt0),
+    {ok, Mt2} = ra_mt:stage({2, 1, <<"data2">>}, Mt1),
+
+    %% Simulate table deletion
+    true = ets:delete(Tid),
+
+    %% Should return empty list since table is deleted
+    {Entries, _Mt3} = ra_mt:commit(Mt2),
+
+    %% Should return empty entries since table was deleted
+    ?assertEqual([], Entries),
+
+    ok.
+
 
 %%% Util