I don't think there is a clearcut rule within the EU. This
recent thread on the BA forum shows a can which was passed no problem at EDI (since they are sold about 100 m from security!) was confiscated at LGW - same airport operator, different rules
It might have helped that EDI staff would know that canned haggis would contain no liquid, whilst LGW staff are generally clueless about things Scottish (previous threads on LGW meeting the tartan army applying
)