Bug Possible to get infinite currency with bank trick

[Jeremy]

A user reported this trick to get infinite currency (slowly) using the bank. They deposit 0.4 currency and the bank sees the 0.4, but the wallet doesn't subtract since it's below a whole number. I first told them that it only appears to be rounded but actually isn't. However, after testing myself I noticed they were actually right: it deposits 0.4 into the bank and takes 0 from the wallet.

 

[Fillip H.]

For the currency in question, is it integrated with DB Credits?

 

[Jeremy]

Yes.

In both Shop and Credits it's set to round to 0 decimal places when publicly displayed (but this is just what's shown, not what they actually have, right?).

 

[Fillip H.]

I'm unable to replicate this issue. If I deposit 2x 0.5 points, my Wallet goes down by 1.

The reason why you're not seeing currency going down when you deposit 0.4 is because it rounds to the nearest whole number (which at 999.60 rounds up to 1000), rather than rounding down.

Can you please test this further?

 

[Jeremy]

I think it might depend on how much money is currently in your wallet when you make a deposit or something like that. At least I tested again and it seemed to increase/decrease from both at first. But then I messed something up and had to do the tests over and it ended up happening again.

Using this query to look at bank on the top and wallet the bottom (same currency, bank is turned off for all others).

SELECT points
FROM xf_dbtech_shop_bank
WHERE user_id = 1
UNION ALL
SELECT credits
FROM xf_user
WHERE user_id = 1

Before doing anything:


After depositing 0.4 first time:


After depositing 0.4 second time:

 

[Fillip H.]

Are you sure the txns aren't in the moderation queue or something?

Moderating bank deposits in DB Credits won't stop them from being deposited into Shop's bank.

 

[Jeremy]

I don't think so, where do I check that exactly?

It doesn't seem consistent and I can't figure out why it does it from testing. Another test:

bank, wallet (deposit before these results) (worked?)
13324.1, 37021.6
13324.6, 37021.5 (0.5) (not exact)
13325.0, 37021.6 (0.4) (not exact)
13325.4, 37021.6 (0.4) (nothing)
13327.4, 37020 (2.0) (not exact)
13327.8, 37019.6 (0.4) (worked)
13328.2, 37019.6 (0.4) (nothing)

But then I edited the bank and wallet values on my test forum to 13324.1 / 37021.6 and it worked fine there.

Maybe it's the version?
Live forum: Shop 6.1.6, Credits 5.5.0
Test forum: both newest betas

Should I wait to test until the live forum is updated too?

 

[Fillip H.]

Yes.

Actually, no

In the Shop currency, if this setting is set to None:


This issue would occur due to an issue with rounding vs display decimals.

If that setting was set to an actual Credits currency, this issue does not occur.

It will be fixed in the next version.

 

[Jeremy]

You're right about the shop currencies. This "integrated currency" setting was never set apparently, but we have them pointed at the same database column. This explains why it wasn't happening on my test forum because the setting is used there. Quick question: will it break anything if I change this setting now even though both add-ons have been in-use for some time now?

 

[Fillip H.]

It will not, it'll simply make Shop transactions show up in the Credits transaction log (events will be auto-generated when they are needed) - and of course this bug will be worked around

 

[DragonByte Technologies]

Hello @Jeremy,

We hope your ticket regarding DragonByte Shop has been addressed to your satisfaction. This ticket has now been scheduled to be closed.

If your ticket has not been resolved, you can reply to this thread at any point in the next 7 days in order to reopen the ticket, afterwards this thread will be closed.

Please do not reply to this thread if your ticket has been resolved.

Thank you.


- DragonByte Technologies, Ltd.

 

[DragonByte Technologies]

Hello @Jeremy,

As we have not heard back from you, your ticket regarding DragonByte Shop has now been closed.

If your ticket has not been resolved, please feel free to start a new support ticket and link back to this ticket.

If you have time, please leave a review on XenForo.com's Resource Manager.

Thank you.


- DragonByte Technologies, Ltd.