not needed merge

Hello, I'm using the Update Command with double j option. Is there any way to 
know wheter a real merge was actually performed? I use the listener and get 
the info from DefaultFileInfoContainer, but sometimes files are reported as 
merged (type G) even if no modification was actually done (i.e. the two -j's 
are equal but pointing to different version numbers).

Thanks for any hint
Sergio