Incorrect return value from pyethereum contract.

[MicahZoltu]

Removing the return type of method bar resolves the issue, though it is completely baffling as to why the return type of bar has any influence on what foo returns.

from ethereum import tester
import os

library = """
def bar():
    return(1: uint256)
"""

code = """
event Message(a)
def foo():
    library = create('garbage.se')
    log(type=Message, library)
    return(library)
"""

with open("garbage.se", "w") as file:
    file.write(library)

try:
    state = tester.state()
    state.block.number += 2000000
    contract = state.abi_contract(code)
    print(contract.foo())
finally:
    os.remove("garbage.se")

Actual Output:

{u'a': 510244585160389217769106449722952381674178085494L, '_event_type': 'Message'}
[]

Expected Output:

{u'a': 510244585160389217769106449722952381674178085494L, '_event_type': 'Message'}
510244585160389217769106449722952381674178085494

[MicahZoltu]

Same problem occurs when garbage.se contains:

def any():
    ~return(0, 32)

[MicahZoltu]

The problem appears to be rooted in serpent.mk_signature(code). In both cases, it is generating an invalid signature like [foo:[]:]. Note the missing return type. Adding an explicit return type to foo via return(library: int256) does not resolve the issue.

[MicahZoltu]

I believe the root cause of this is ethereum/serpent#119. Pyethereum should do a better job of failing in this case though, I have probably sunk 2-3 days of effort debugging and troubleshooting this issue, if Pyethereum would have just failed hard on the invalid signature from serpent I would have narrowed down the issue much faster.