If value of contract call is <= 0 or > contract balance call will not be made and expression will return 0.

[MicahZoltu]

I consider this to be a security issue because it is super easy to not realize that this is the behavior and result in potentially not calling a method that should have been called, yet returning a well defined value. This could allow a clever attacker to get a script to do what they want.

This prints 2, should throw. Changing value = 0 to value = 2 results in the same behavior.

from ethereum import tester
import serpent

code = """
def foo():
    return 5

def bar():
    result = self.foo(value = 0)
    return result + 2
"""

state = tester.state()
state.block.number += 2000000
contract = state.abi_contract(code)
print contract.bar(value = 1)