adapter: fix orphaned list items when DEL + recreate in same Lua script

adapter/redis_lua_compat_test.go

@@ -172,3 +172,34 @@ return {moved, redis.call("LLEN", KEYS[1])}
 	require.NoError(t, err)
 	require.Greater(t, ttl, time.Duration(0))
 }
+
+func TestRedis_LuaDelAndRecreateListNoOrphan(t *testing.T) {
+	nodes, _, _ := createNode(t, 3)
+	defer shutdown(nodes)
+
+	ctx := context.Background()
+	rdb := redis.NewClient(&redis.Options{Addr: nodes[0].redisAddress})
+	defer func() { _ = rdb.Close() }()
+
+	// Pre-populate a list so there are existing storage items.
+	require.NoError(t, rdb.RPush(ctx, "mylist", "a", "b", "c").Err())
+
+	// In a single Lua script: DEL the key, then recreate it as a list.
+	// After the script, only the new items should be visible; the old
+	// [a, b, c] items must not be orphaned/leaked in storage.
+	result, err := rdb.Eval(ctx, `
+redis.call("DEL", KEYS[1])
+redis.call("RPUSH", KEYS[1], "d")
+return redis.call("LRANGE", KEYS[1], 0, -1)
+`, []string{"mylist"}).Result()
+	require.NoError(t, err)
+
+	values, ok := result.([]any)
+	require.True(t, ok)
+	require.Equal(t, []any{"d"}, values, "list should contain only the newly pushed item")
+
+	// Verify via a plain LRANGE that the old items are gone.
+	final, err := rdb.LRange(ctx, "mylist", 0, -1).Result()
+	require.NoError(t, err)
+	require.Equal(t, []string{"d"}, final)
+}

adapter/redis_lua_context.go

@@ -19,8 +19,9 @@ type luaScriptContext struct {
 	startTS uint64
 	readPin *kv.ActiveTimestampToken
 
-	touched map[string]struct{}
-	deleted map[string]bool
+	touched     map[string]struct{}
+	deleted     map[string]bool
+	everDeleted map[string]bool
 
 	strings map[string]*luaStringState
 	lists   map[string]*luaListState
@@ -189,18 +190,19 @@ var luaRenameHandlers = map[redisValueType]luaRenameHandler{
 func newLuaScriptContext(server *RedisServer) *luaScriptContext {
 	startTS := server.readTS()
 	return &luaScriptContext{
-		server:  server,
-		startTS: startTS,
-		readPin: server.pinReadTS(startTS),
-		touched: map[string]struct{}{},
-		deleted: map[string]bool{},
-		strings: map[string]*luaStringState{},
-		lists:   map[string]*luaListState{},
-		hashes:  map[string]*luaHashState{},
-		sets:    map[string]*luaSetState{},
-		zsets:   map[string]*luaZSetState{},
-		streams: map[string]*luaStreamState{},
-		ttls:    map[string]*luaTTLState{},
+		server:      server,
+		startTS:     startTS,
+		readPin:     server.pinReadTS(startTS),
+		touched:     map[string]struct{}{},
+		deleted:     map[string]bool{},
+		everDeleted: map[string]bool{},
+		strings:     map[string]*luaStringState{},
+		lists:       map[string]*luaListState{},
+		hashes:      map[string]*luaHashState{},
+		sets:        map[string]*luaSetState{},
+		zsets:       map[string]*luaZSetState{},
+		streams:     map[string]*luaStreamState{},
+		ttls:        map[string]*luaTTLState{},
 	}
 }
 
@@ -265,6 +267,7 @@ func (c *luaScriptContext) deleteLogical(key []byte) {
 	k := string(key)
 	c.markTouched(key)
 	c.deleted[k] = true
+	c.everDeleted[k] = true
 	c.clearTTL(key)
 
 	if st, ok := c.strings[k]; ok {
@@ -2517,6 +2520,14 @@ func (c *luaScriptContext) listCommitPlan(key string) (luaCommitPlan, error) {
 		elems, err := c.listCommitElems(key)
 		return luaCommitPlan{elems: elems}, err
 	}
+	// If the key was deleted earlier in this script and later recreated as a
+	// list, we must perform a full rewrite (preserveExisting=false) so that
+	// deleteLogicalKeyElems is called and any orphaned storage items from the
+	// previous incarnation of the key are cleaned up before writing the delta.
+	if c.everDeleted[key] {
+		elems, err := c.listCommitElems(key)
+		return luaCommitPlan{elems: elems}, err
+	}
 	elems, err := c.listDeltaCommitElems(key, st)
 	return luaCommitPlan{preserveExisting: true, elems: elems}, err
 }

proxy/proxy.go

@@ -335,7 +335,7 @@ func (p *ProxyServer) handleAdmin(conn redcon.Conn, name string, args [][]byte)
 	// uses a shared connection pool and cannot maintain per-client DB state.
 	if name == "SELECT" {
 		// Redis arity: SELECT <db>. Require exactly one DB argument.
-		if len(args) != 2 {
+		if len(args) != selectArgCount {
 			conn.WriteError("ERR wrong number of arguments for 'select' command")
 			return
 		}

proxy/pubsub.go

@@ -20,6 +20,7 @@ const (
 	pubsubArrayReply    = 3 // ["subscribe"/"unsubscribe", channel, count]
 	pubsubArrayPong     = 2 // ["pong", data]
 	pubsubMinArgs       = 2 // command + at least one channel
+	selectArgCount      = 2 // command name + db index argument
 
 	cmdSubscribe    = "SUBSCRIBE"
 	cmdUnsubscribe  = "UNSUBSCRIBE"
@@ -334,7 +335,7 @@ func (s *pubsubSession) handleProxySpecialCommand(name string, args [][]byte) bo
 		return false
 	}
 	// Enforce Redis arity: SELECT requires exactly one DB index argument.
-	if len(args) != 2 {
+	if len(args) != selectArgCount {
 		s.writeError("ERR wrong number of arguments for 'select' command")
 		return true
 	}