When connecting, the ThinLinc client uses SSH to talk to the ThinLinc master (to get assigned to an agent). When this SSH connection is finished and the SSH process should be terminated we always wait 1.5 seconds for it to let us know that it has terminated properly. The SSH process will however never tell us that, leading to that we always waits 1.5 seconds in vein.
Furthermore, the SSH process will not react to our message telling it to shut down cleanly, leading to that it always times out after 1.5 seconds. After the timeout a hard kill is performed on the process.
The timeout that we always hit has now been removed. This makes the ThinLinc client connection 1.5 seconds faster on Windows.
Unfortunately the granularity of the log timestamp makes it difficult to perfectly test this, but it seems like we indeed have 1.5 seconds faster login.
4.7.0: 3 seconds to killing SSH, 6 seconds to fully logged in
4.9.0: 3 seconds to killing SSH, 5 seconds to fully logged in (1st test)
4.9.0: 2 seconds to killing SSH, 4 seconds to fully logged in (2nd test)
Couldn't see any other problems. Other processes are still cleaned up properly, and nothing new gets a hard kill.