I suggest that you look at AIC 127/1999 (White 378). It is a training flight but you do have to satisfy the instructor as to your ability.
You would not expect an instructor to send a student solo if he was not up to it. Equally you should not expect to get a signature just for being in the same aircraft as the instructor.
Edit to add that night and IMC "training" will not count. It has to be the test/check (see item 1.3 ii) although it does not say that it has to be a pass
