Under Session --> Save Session, user types a long name including all characters including digits, alphabets, and special characters, it gets saved as a valid connection name.
Also, the long names are broken into pieces in order to accommodate them under Session --> Saved Session option.
The WinSCP login window shows long names with horizontal scroll bars and in folder hierarchy style in its right pane.
It would be better to enforce a limit on the number of characters in Session name.