Input list of flashloan tokens is either ignored or used as a filter

[barakman]

Bug Description

Suspected bug or improper product definition.

In the B3-Two-Hop arbitrage mode, the user's input list of flashloan tokens is either ignored or used as a filter:

• When the user specifies --limit_bancor3_flashloan_tokens=true, the input list of flashloan tokens is filtered to include only bancor v3 tradable tokens.
• When the user specifies --limit_bancor3_flashloan_tokens=false, the input list of flashloan tokens is completely ignored, and the list of all bancor v3 tradable tokens is used instead.

Severity

High

Steps to Reproduce

As you can see in base.py, self.flashloan_tokens is set as a list of some or all of the tokens in fltkns, which is by itself a list of all bancor v3 tradable tokens:

def _check_limit_flashloan_tokens_for_bancor3(self):
    """
    Limit the flashloan tokens for bancor v3.
    """
    fltkns = self.CCm.byparams(exchange="bancor_v3").tknys()
    if self.ConfigObj.LIMIT_BANCOR3_FLASHLOAN_TOKENS:
        # Filter out tokens that are not in the existing flashloan_tokens list
        self.flashloan_tokens = [
            tkn for tkn in fltkns if tkn in self.flashloan_tokens
        ]
        self.ConfigObj.logger.info(
            f"[modes.base._check_limit_flashloan_tokens_for_bancor3] limiting flashloan_tokens to {self.flashloan_tokens}"
        )
    else:
        self.flashloan_tokens = fltkns