From 06e08a65e4e8bde4ea98cbd6c40348637988490a Mon Sep 17 00:00:00 2001
From: richjohnrambo <richjohnrambo@gmail.com>
Date: Wed, 30 Sep 2026 10:50:35 +0800
Subject: [PATCH] fix: handle opaque attachment references

---
 loadtest/im-pressure/dbverify.go      | 36 ++++++++++++++++++---------
 loadtest/im-pressure/dbverify_test.go | 24 ++++++++++++++++++
 server/store/file_test.go             | 30 ++++++++++++++++++++++
 server/store/store.go                 | 12 +++++++--
 4 files changed, 88 insertions(+), 14 deletions(-)
 create mode 100644 loadtest/im-pressure/dbverify_test.go
 create mode 100644 server/store/file_test.go

diff --git a/loadtest/im-pressure/dbverify.go b/loadtest/im-pressure/dbverify.go
index a242938..9039363 100644
--- a/loadtest/im-pressure/dbverify.go
+++ b/loadtest/im-pressure/dbverify.go
@@ -41,8 +41,9 @@ func runDBVerify(ctx context.Context, coordinatorPath, output, tenantCode, dsnEn
 		return err
 	}
 	var coordinator struct {
-		Start   StartInfo                    `json:"start"`
-		Ledgers map[string][]AcceptedMessage `json:"ledgers"`
+		Start    StartInfo                    `json:"start"`
+		Ledgers  map[string][]AcceptedMessage `json:"ledgers"`
+		Observed map[string][]AcceptedMessage `json:"observed"`
 	}
 	if err = json.Unmarshal(raw, &coordinator); err != nil {
 		return fmt.Errorf("decode coordinator: %w", err)
@@ -77,17 +78,11 @@ func runDBVerify(ctx context.Context, coordinatorPath, output, tenantCode, dsnEn
 		return err
 	}
 
-	expected := make(map[string]AcceptedMessage)
+	expected := expectedDBMessages(coordinator.Start.RunID, coordinator.Ledgers, coordinator.Observed)
 	months := make(map[string]struct{})
-	for _, ledger := range coordinator.Ledgers {
-		for _, message := range ledger {
-			if message.RunID != coordinator.Start.RunID {
-				continue
-			}
-			expected[message.ClientMid] = message
-			if message.Kind == "group" {
-				months[message.SentAt.UTC().Format("200601")] = struct{}{}
-			}
+	for _, message := range expected {
+		if message.Kind == "group" {
+			months[message.SentAt.UTC().Format("200601")] = struct{}{}
 		}
 	}
 	tables := []string{fmt.Sprintf("im_%03d_messages", tenantID)}
@@ -167,3 +162,20 @@ func runDBVerify(ctx context.Context, coordinatorPath, output, tenantCode, dsnEn
 	}
 	return nil
 }
+
+func expectedDBMessages(runID string, ledgers, observed map[string][]AcceptedMessage) map[string]AcceptedMessage {
+	all := make([]AcceptedMessage, 0)
+	for _, messages := range observed {
+		all = append(all, messages...)
+	}
+	for _, messages := range ledgers {
+		all = append(all, messages...)
+	}
+	expected := make(map[string]AcceptedMessage, len(all))
+	for _, message := range mergeMessageLedgers(nil, all) {
+		if message.RunID == runID && message.ClientMid != "" {
+			expected[message.ClientMid] = message
+		}
+	}
+	return expected
+}
diff --git a/loadtest/im-pressure/dbverify_test.go b/loadtest/im-pressure/dbverify_test.go
new file mode 100644
index 0000000..280a71c
--- /dev/null
+++ b/loadtest/im-pressure/dbverify_test.go
@@ -0,0 +1,24 @@
+package main
+
+import "testing"
+
+func TestExpectedDBMessagesIncludesObservedWithoutAck(t *testing.T) {
+	ledgers := map[string][]AcceptedMessage{
+		"a": {{RunID: "run-1", ClientMid: "acked", Topic: "grp-one", Seq: 1}},
+	}
+	observed := map[string][]AcceptedMessage{
+		"a": {
+			{RunID: "run-1", ClientMid: "unacked", Topic: "grp-one", Seq: 2},
+			{RunID: "other", ClientMid: "foreign", Topic: "grp-one", Seq: 3},
+		},
+		"b": {{RunID: "run-1", ClientMid: "unacked", Topic: "grp-one", Seq: 2}},
+	}
+
+	expected := expectedDBMessages("run-1", ledgers, observed)
+	if len(expected) != 2 {
+		t.Fatalf("expected messages=%d want=2: %+v", len(expected), expected)
+	}
+	if expected["acked"].Seq != 1 || expected["unacked"].Seq != 2 {
+		t.Fatalf("unexpected merged messages: %+v", expected)
+	}
+}
diff --git a/server/store/file_test.go b/server/store/file_test.go
new file mode 100644
index 0000000..b1515e0
--- /dev/null
+++ b/server/store/file_test.go
@@ -0,0 +1,30 @@
+package store
+
+import (
+	"testing"
+
+	"github.com/tinode/chat/server/store/types"
+)
+
+func TestFileLinkUserIDAllowsOpaqueTopicReferences(t *testing.T) {
+	tests := []struct {
+		name    string
+		topic   string
+		isUser  bool
+		wantUID types.Uid
+	}{
+		{name: "cultivate reference", topic: "cvpbzxw1aio4ni8x0"},
+		{name: "short opaque reference", topic: "x"},
+		{name: "empty reference", topic: ""},
+		{name: "user reference", topic: types.Uid(42).UserId(), isUser: true, wantUID: types.Uid(42)},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			gotUID, gotIsUser := fileLinkUserID(test.topic)
+			if gotIsUser != test.isUser || gotUID != test.wantUID {
+				t.Fatalf("fileLinkUserID(%q) = (%v, %v), want (%v, %v)", test.topic, gotUID, gotIsUser, test.wantUID, test.isUser)
+			}
+		})
+	}
+}
diff --git a/server/store/store.go b/server/store/store.go
index e353a81..051380d 100644
--- a/server/store/store.go
+++ b/server/store/store.go
@@ -4684,8 +4684,8 @@ func (fileMapper) LinkAttachments(tenantID types.TenantID, topic string, msgId t
 			return err
 		}
 		userId := types.ZeroUid
-		if topic != "" && types.GetTopicCat(topic) == types.TopicCatMe {
-			userId = types.ParseUserId(topic)
+		if parsedUserID, ok := fileLinkUserID(topic); ok {
+			userId = parsedUserID
 			topic = ""
 		}
 		return tenantAdp.TenantFileLinkAttachments(tenantID, topic, userId, msgId, fids)
@@ -4693,6 +4693,14 @@ func (fileMapper) LinkAttachments(tenantID types.TenantID, topic string, msgId t
 	return nil
 }
 
+// File link topics may also be opaque retention keys, such as cultivate's cvp prefix.
+func fileLinkUserID(topic string) (types.Uid, bool) {
+	if !strings.HasPrefix(topic, "usr") {
+		return types.ZeroUid, false
+	}
+	return types.ParseUserId(topic), true
+}
+
 func (fileMapper) UserHasAccess(tenantID types.TenantID, fid string, uid types.Uid) (bool, error) {
 	if fid == "" || uid.IsZero() {
 		return false, types.ErrMalformed