eshell: annoying filename completion

[Barman Brakjoller]

Imagine you have this:

~/tmp/esh $ ls
long_file_name.gif

and want to do this

~/tmp/esh $ rm long_<pressing TAB here completes the filename>

That works ok, eshell completes the filename. But what if I want to
rename that file to long_file_name.jpeg? This does not work as I want:

~/tmp/esh $ mv long_<pressing TAB here completes the filename> lo<TAB
again, nothing happens, eshell just beeps at me>

I guess eshell is trying to be smart here, but in this case it is too
smart for my taste... :)

Any variable I might want to customize and any drawbacks?