Funny film shortened — would be, too, if the ending was cut (4)

'funny film' is the definition.
(cartoon)

'shortened would be too if the ending was cut' is the wordplay.
I cannot quite see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
The remaining letters 'oon' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).