abi length is too short for nested tuples

[charles-cooper]

Version Information

• vyper Version (output of vyper --version): v0.2.16

What's your issue about?

The size bound for nested tuples is too small. For example abi_encode of a ((Bytes[6],),) should have a size bound of 128, but the following compiles with no issue:

struct WrappedBytes: # equivalent to (Bytes[6],)
    bs: Bytes[6]

@internal
def foo():
    x: WrappedBytes = WrappedBytes({bs: b"hello"})
    y: Bytes[96] = _abi_encode(x, ensure_tuple=True)

How can it be fixed?

Fix the size bound estimate in vyper/old_codegen/abi.py

[charles-cooper]

fixed in #2447