Missing Error for Invalid Miniscript (t Wrapper Issue)

[odudex]

@brunoerg, while comparing Embit's Miniscript implementations with Bitcoin Core and Rust Miniscript, with his Bitcoin Fuzz tool, discovered an unexpected behavior in Embit: It doesn’t raise an error when a specific invalid Miniscript is loaded.
bitcoinfuzz/bitcoinfuzz#113
@darosior noted that a t wrapper must be followed by a V type fragment for the descriptor to be valid. Although Miniscript logic is still new territory for me, I implemented a verification in the t wrapper class to further explore the issue and propose a solution.
Edit: Verification code available on PR mentioned below.

[brunoerg]

Thanks, @odudex.

[odudex]

Thank you @brunoerg ! Nice catch, with a great tool!