fix im forwarding and message list regressions

server/db/mysql/report_group_regression_test.go

@@ -55,6 +55,47 @@ func TestMessageSearchDoesNotClearScannedHead(t *testing.T) {
 	}
 }
 
+func TestSearchPaginationCursorUsesLastReturnedRow(t *testing.T) {
+	source, err := os.ReadFile("tenant_adapter.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	body := string(source)
+	for _, tc := range []struct {
+		name      string
+		function  string
+		forbidden string
+		required  string
+	}{
+		{
+			name:      "p2p message search",
+			function:  "func (a *adapter) TenantMessageSearch",
+			forbidden: "nextCursor = strconv.FormatInt(msg.SeqId, 10)",
+			required:  "nextCursor = strconv.FormatInt(lastSeq, 10)",
+		},
+		{
+			name:      "group message search",
+			function:  "func (a *adapter) tenantGroupMessageSearch",
+			forbidden: "nextCursor = strconv.FormatInt(msg.SeqId, 10)",
+			required:  "nextCursor = strconv.FormatInt(lastSeq, 10)",
+		},
+		{
+			name:      "favorite list",
+			function:  "func (a *adapter) TenantFavoriteList",
+			forbidden: "nextCursor = strconv.FormatInt(item.ID, 10)",
+			required:  "nextCursor = strconv.FormatInt(lastID, 10)",
+		},
+	} {
+		fn := functionSource(t, body, tc.function)
+		if strings.Contains(fn, tc.forbidden) {
+			t.Fatalf("%s must not use the extra fetched row as next cursor", tc.name)
+		}
+		if !strings.Contains(fn, tc.required) {
+			t.Fatalf("%s must use the last returned row as next cursor", tc.name)
+		}
+	}
+}
+
 func TestTenantFileAccessIncludesAvatarAudienceRules(t *testing.T) {
 	source, err := os.ReadFile("tenant_adapter.go")
 	if err != nil {
@@ -72,3 +113,16 @@ func TestTenantFileAccessIncludesAvatarAudienceRules(t *testing.T) {
 		}
 	}
 }
+
+func functionSource(t *testing.T, source, marker string) string {
+	t.Helper()
+	start := strings.Index(source, marker)
+	if start < 0 {
+		t.Fatalf("function %q not found", marker)
+	}
+	next := strings.Index(source[start+len(marker):], "\nfunc ")
+	if next < 0 {
+		return source[start:]
+	}
+	return source[start : start+len(marker)+next]
+}