Alice and Bob using the 1to1 chat.
If Alice now invites Bob:
1. Alice chat contents are cleared and are redisplayed after Bob accepted the invitation
2. Bobs chat contents are cleared after accepting the invitation and are never restored
After Bob leaves the session, the chat content is correctly restored.
There was one chat-related patch missing: http://saros-build.imp.fu-berlin.de/gerrit/356
7b662410ef8444bccc1de438b2cef4363be5a16a