[MM-60083] export: do not export DMs/GMs if users are deleted (#28854)

server/channels/app/export.go

@@ -121,7 +121,11 @@ func (a *App) BulkExport(ctx request.CTX, writer io.Writer, outPath string, job
 		}
 	}
 
-	if job != nil && job.Data == nil {
+	if job == nil {
+		job = &model.Job{
+			Data: make(model.StringMap),
+		}
+	} else if job.Data == nil {
 		job.Data = make(model.StringMap)
 	}
 
@@ -944,14 +948,38 @@ func (a *App) exportAllDirectChannels(ctx request.CTX, job *model.Job, writer io
 		for _, channel := range channels {
 			afterId = channel.Id
 
+			// Skip deleted.
+			if channel.DeleteAt != 0 {
+				continue
+			}
+
 			// Skip if there are no active members in the channel
 			if len(channel.Members) == 0 {
 				continue
 			}
 
-			// Skip deleted.
-			if channel.DeleteAt != 0 {
-				continue
+			// Skip if the channel member structure is not intact
+			switch channel.Type {
+			case model.ChannelTypeGroup:
+				groupMembers := make([]string, len(channel.Members))
+				for i, m := range channel.Members {
+					groupMembers[i] = m.UserId
+				}
+				if channel.Name != model.GetGroupNameFromUserIds(groupMembers) {
+					// this is the case of a group channel when other user is permanently deleted
+					// we skip this channel and inform by logging it.
+					job.Data["skipped_direct_channels"] = job.Data["skipped_direct_channels"] + "," + channel.Id
+					ctx.Logger().Warn("Skipping group channels with partially deleted members", mlog.String("channel_id", channel.Id))
+					continue
+				}
+			case model.ChannelTypeDirect:
+				if _, u2 := channel.GetBothUsersForDM(); u2 != "" && len(channel.Members) == 1 {
+					// this is the case of a direct channel when other user is permanently deleted
+					// we skip this channel and inform by logging it.
+					job.Data["skipped_direct_channels"] = job.Data["skipped_direct_channels"] + "," + channel.Id
+					ctx.Logger().Info("Skipping direct channel with one active member", mlog.String("channel_id", channel.Id), mlog.String("user_id", channel.Members[0].UserId))
+					continue
+				}
 			}
 
 			favoritedBy, err := a.buildFavoritedByList(channel.Id)
@@ -1070,6 +1098,7 @@ func (a *App) exportAllDirectPosts(ctx request.CTX, job *model.Job, writer io.Wr
 		cnt += len(posts)
 		updateJobProgress(ctx.Logger(), a.Srv().Store(), job, "direct_posts_exported", cnt)
 
+		channelsToSkip := model.SliceToMapKey(strings.Split(job.Data["skipped_direct_channels"], ",")...)
 		for _, post := range posts {
 			afterId = post.Id
 			postProcessCount++
@@ -1079,6 +1108,10 @@ func (a *App) exportAllDirectPosts(ctx request.CTX, job *model.Job, writer io.Wr
 				continue
 			}
 
+			if _, ok := channelsToSkip[post.ChannelId]; ok {
+				continue
+			}
+
 			// Handle attachments.
 			var postAttachments []imports.AttachmentImportData
 			var err *model.AppError

server/channels/app/export_test.go

@@ -355,6 +355,50 @@ func TestExportDMChannel(t *testing.T) {
 		require.NoError(t, nErr)
 		assert.Empty(t, channels)
 	})
+
+	t.Run("Should not export DM channel if other user is permanently deleted", func(t *testing.T) {
+		th1 := Setup(t).InitBasic()
+		defer th1.TearDown()
+
+		// Create a DM Channel with another user
+		dmc1 := th1.CreateDmChannel(th1.BasicUser2)
+		th1.CreatePost(dmc1)
+
+		// Create a DM Channel with self
+		dmc2 := th1.CreateDmChannel(th1.BasicUser)
+		th1.CreatePost(dmc2)
+
+		channels, nErr := th1.App.Srv().Store().Channel().GetAllDirectChannelsForExportAfter(1000, "00000000", false)
+		require.NoError(t, nErr)
+		assert.Equal(t, 2, len(channels))
+
+		// Permanentley delete other user
+		th1.App.PermanentDeleteUser(th1.Context, th1.BasicUser2)
+
+		var b bytes.Buffer
+		err := th1.App.BulkExport(th1.Context, &b, "somePath", nil, model.BulkExportOpts{})
+		require.Nil(t, err)
+
+		th2 := Setup(t).InitBasic()
+		defer th2.TearDown()
+
+		// import the exported channel
+		err, _ = th2.App.BulkImport(th2.Context, &b, nil, false, 5)
+		require.Nil(t, err)
+
+		channels, nErr = th2.App.Srv().Store().Channel().GetAllDirectChannelsForExportAfter(1000, "00000000", false)
+		require.NoError(t, nErr)
+		assert.Equal(t, 1, len(channels))
+
+		// Ensure the posts of the deleted DM channel do not leak to the self-DM channel
+		posts, nErr := th2.App.Srv().Store().Post().GetPosts(model.GetPostsOptions{
+			ChannelId:      channels[0].Id,
+			PerPage:        1000,
+			IncludeDeleted: true,
+		}, false, nil)
+		require.NoError(t, nErr)
+		assert.Equal(t, 1, len(posts.Posts))
+	})
 }
 
 func TestExportDMChannelToSelf(t *testing.T) {

server/channels/app/import_functions.go

@@ -2327,12 +2327,15 @@ func (a *App) importMultipleDirectPostLines(rctx request.CTX, lines []imports.Li
 				return line.LineNumber, model.NewAppError("BulkImport", "app.import.import_direct_post.create_direct_channel.error", nil, "", http.StatusBadRequest).Wrap(err)
 			}
 			channel = ch
-		} else {
+		} else if len(userIDs) > 2 {
 			ch, err = a.createGroupChannel(rctx, userIDs)
 			if err != nil && err.Id != store.ChannelExistsError {
 				return line.LineNumber, model.NewAppError("BulkImport", "app.import.import_direct_post.create_group_channel.error", nil, "", http.StatusBadRequest).Wrap(err)
 			}
 			channel = ch
+		} else {
+			rctx.Logger().Warn("Not enough users to create a direct channel", mlog.Int("line_number", line.LineNumber))
+			continue
 		}
 
 		user := users[strings.ToLower(*line.DirectPost.User)]

server/public/model/metrics.go

@@ -40,11 +40,11 @@ const (
 
 var (
 	performanceReportVersion = semver.MustParse("0.1.0")
-	acceptedPlatforms        = sliceToMapKey("linux", "macos", "ios", "android", "windows", "other")
-	acceptedAgents           = sliceToMapKey("desktop", "firefox", "chrome", "safari", "edge", "other")
+	acceptedPlatforms        = SliceToMapKey("linux", "macos", "ios", "android", "windows", "other")
+	acceptedAgents           = SliceToMapKey("desktop", "firefox", "chrome", "safari", "edge", "other")
 
-	AcceptedInteractions = sliceToMapKey("keyboard", "pointer", "other")
-	AcceptedLCPRegions   = sliceToMapKey(
+	AcceptedInteractions = SliceToMapKey("keyboard", "pointer", "other")
+	AcceptedLCPRegions   = SliceToMapKey(
 		"post",
 		"post_textbox",
 		"channel_sidebar",
@@ -56,8 +56,8 @@ var (
 		"modal_content",
 		"other",
 	)
-	AcceptedTrueFalseLabels     = sliceToMapKey("true", "false")
-	AcceptedSplashScreenOrigins = sliceToMapKey("root", "team_controller")
+	AcceptedTrueFalseLabels     = SliceToMapKey("true", "false")
+	AcceptedSplashScreenOrigins = SliceToMapKey("root", "team_controller")
 )
 
 type MetricSample struct {

server/public/model/utils.go

@@ -860,7 +860,7 @@ func IsCloud() bool {
 	return os.Getenv("MM_CLOUD_INSTALLATION_ID") != ""
 }
 
-func sliceToMapKey(s ...string) map[string]any {
+func SliceToMapKey(s ...string) map[string]any {
 	m := make(map[string]any)
 	for i := range s {
 		m[s[i]] = struct{}{}