MM-11174: Fix /msg slash command. (#9059)

app/command_msg.go

@@ -66,6 +66,10 @@ func (me *msgProvider) DoCommand(a *App, args *model.CommandArgs, message string
 	targetChannelId := ""
 	if channel := <-a.Srv.Store.Channel().GetByName(args.TeamId, channelName, true); channel.Err != nil {
 		if channel.Err.Id == "store.sql_channel.get_by_name.missing.app_error" {
+			if !a.SessionHasPermissionTo(args.Session, model.PERMISSION_CREATE_DIRECT_CHANNEL) {
+				return &model.CommandResponse{Text: args.T("api.command_msg.permission.app_error"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+			}
+
 			if directChannel, err := a.CreateDirectChannel(args.UserId, userProfile.Id); err != nil {
 				mlog.Error(err.Error())
 				return &model.CommandResponse{Text: args.T("api.command_msg.dm_fail.app_error"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}