#13586 solved the relation between subtasks. so subtasks has no relations can make new relation now.
but try to move tasks have relation under a task, "Failed to save 1 issue(s) on 2 selected: #xxx." is occurred.(only first issue is moved)
and try to move #xxx under parent issue, "Parent task is invalid" is occurred.
after remove the relation, it's OK.
I tested these things under r11692 rev.11692
About your application's environment
Ruby version 1.9.2 (x86_64-linux)
RubyGems version 1.8.24
Rack version 1.4
Rails version 3.2.13
Active Record version 3.2.13
Action Pack version 3.2.13
Active Resource version 3.2.13
Action Mailer version 3.2.13
Active Support version 3.2.13
Middleware Rack::Cache, ActionDispatch::Static, Rack::Lock, #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000002da4290>, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Callbacks, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, ActionDispatch::Head, Rack::ConditionalGet, Rack::ETag, ActionDispatch::BestStandardsSupport, OpenIdAuthentication
Application root /data/redmine
Database adapter mysql2
Database schema version 20130217094251