build(deps): bump actions/download-artifact from 4 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v4...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/benchstat.yml

@@ -69,11 +69,11 @@ jobs:
       - name: Install benchstat
         run: go get -u golang.org/x/perf/cmd/benchstat
       - name: Download Incoming
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
           name: bench-incoming
       - name: Download Current
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
           name: bench-current
       - name: Benchstat Results

internal/rdb/inspect.go

@@ -264,7 +264,9 @@ for i=1,2 do
     if (table.getn(ids) > 0) then
         for _, id in ipairs(ids) do
             local bytes = redis.call("MEMORY", "USAGE", ARGV[1] .. id)
-            sample_total = sample_total + bytes
+            if bytes then
+                sample_total = sample_total + bytes
+            end
         end
         local n = redis.call("LLEN", KEYS[i])
         local avg = sample_total / table.getn(ids)
@@ -281,7 +283,9 @@ for i=3,6 do
     if (table.getn(ids) > 0) then
         for _, id in ipairs(ids) do
             local bytes = redis.call("MEMORY", "USAGE", ARGV[1] .. id)
-            sample_total = sample_total + bytes
+            if bytes then
+                sample_total = sample_total + bytes
+            end
         end
         local n = redis.call("ZCARD", KEYS[i])
         local avg = sample_total / table.getn(ids)
@@ -304,13 +308,17 @@ if table.getn(groups) > 0 then
 			local ids = redis.call("ZRANGE", group_key, 0, sample_size - 1)
 			for _, id in ipairs(ids) do
 				local bytes = redis.call("MEMORY", "USAGE", ARGV[1] .. id)
-				agg_task_sample_total = agg_task_sample_total + bytes
-				agg_task_sample_size = agg_task_sample_size + 1
+				if bytes then
+					agg_task_sample_total = agg_task_sample_total + bytes
+					agg_task_sample_size = agg_task_sample_size + 1
+				end
 			end
 		end
 	end
-	local avg = agg_task_sample_total / agg_task_sample_size
-	memusg = memusg + (avg * agg_task_count)
+	if agg_task_sample_size > 0 then
+		local avg = agg_task_sample_total / agg_task_sample_size
+		memusg = memusg + (avg * agg_task_count)
+	end
 end
 return memusg
 `)

internal/rdb/rdb.go

@@ -1488,6 +1488,7 @@ func (r *RDB) CancelationPubSub() (*redis.PubSub, error) {
 	pubsub := r.client.Subscribe(ctx, base.CancelChannel)
 	_, err := pubsub.Receive(ctx)
 	if err != nil {
+		pubsub.Close()
 		return nil, errors.E(op, errors.Unknown, fmt.Sprintf("redis pubsub receive error: %v", err))
 	}
 	return pubsub, nil

internal/rdb/rdb_test.go

@@ -3274,6 +3274,29 @@ func TestCancelationPubSub(t *testing.T) {
 	mu.Unlock()
 }
 
+func TestCancelationPubSubReceiveError(t *testing.T) {
+	// Use a client connected to a non-existent Redis server to trigger
+	// a Receive() error. This verifies that the pubsub connection is
+	// closed on error, preventing connection leaks.
+	client := redis.NewClient(&redis.Options{
+		Addr: "localhost:0", // invalid port — connection will fail
+	})
+	r := NewRDB(client)
+	defer r.Close()
+
+	pubsub, err := r.CancelationPubSub()
+	if err == nil {
+		// If no error, we must clean up the pubsub.
+		if pubsub != nil {
+			pubsub.Close()
+		}
+		t.Fatal("(*RDB).CancelationPubSub() expected to return an error when redis is unreachable")
+	}
+	if pubsub != nil {
+		t.Error("(*RDB).CancelationPubSub() expected nil pubsub on error")
+	}
+}
+
 func TestWriteResult(t *testing.T) {
 	r := setup(t)
 	defer r.Close()