in open_channel in raiden/api/rest.py it allow the user to create a channel without any funds

[Giulio2002]

Scenario

i have no W-Eth and no unsettled channels as well. Therefore i can't join W-Eth token network.
i try to create a channel anyway with:

curl -i -X PUT http://localhost:5001/api/1/channels -H 'Content-Type: application/json' --data-raw '{"partner_address": "0x61C808D82A3Ac53231750daDc13c777b59310bD9", "settle_timeout": 500, "token_address": "0xc778417E063141139Fce010982780140Aa0cD5Ab", "total_deposit": 5000000}'

obviously i have 0 W-Eth, so i get this error:

Not enough balance to deposit. c778417e Available=0 Needed=5000000

despite the error if we execute

curl -i http://localhost:5001/api/1/channels

and then we can see from the output that a channel have been created and that we have been joined automatically the token Network W-Eth without any funds in it.

[{
state: 'opened',
    total_deposit: 0,
    partner_address: 0x61C808D82A3Ac53231750daDc13c777b59310bD9',
    settle_timeout: 500,
    token_network_identifier: '0xa1DE2cD74eFE0EDa3989aa6C1fa3B632927770A8',
    balance: 0,
    reveal_timeout: 50,
    channel_identifier: 31,
    token_address: '0xc778417E063141139Fce010982780140Aa0cD5Ab' }]

[Giulio2002]

i made also a pr that solve this bug if you want you can look at it:

[LefterisJP]

Hello @Giulio2002. Thanks for the report.

I think you are correct in thinking this is a bug.

What happens is that:

1. We combine the channel open and deposit in one call of the REST API
2. First channel open happens
3. Then deposit happens. The balance check is only made during deposit.

It would make sense to have a balance check at the rest api level before even allowing to open a channel. I will comment on your PR.

[Giulio2002]

[Giulio2002]

#3023