BUG/MEDIUM: stconn: Propagate error on the SC on sending path

On sending path, a pending error can be promoted to a terminal error at the
endpoint level (SE_FL_ERR_PENDING to SE_FL_ERROR). When this happens, we
must propagate the error on the SC to be able to handle it at the stream
level and eventually forward it to the other side.

Because of this bug, it is possible to freeze sessions, for instance on the
CLI.

It is a 2.8-specific issue. No backport needed.
1 file changed