Apply asfDisallowIncomingTrustline blocker to OfferCreate txn

[dangell7]

Issue Description

The asfDisallowIncomingTrustline flag was introduced in #4336. When introduced it was not applied to the CreateOffer transactor.

I believe it should be. The functionality should be similar to the asfRequireAuth flag.

Steps to Reproduce

• Issuer "issues" USD token. (Distribution account establishes trustline ("USD") with Issuer and Issuer funds Distribution account)
• Distribution account creates a sell offer.
• Issuer sets asfDisallowIncomingTrustline flag.
• User submits CreateOffer txn without a trustline for the USD currency.

The offers cross and the user now owns the token with a 0 LimitAmount Trustline. The user cannot make payments with the token but could sell the token with an offer.

Expected Result

I would expect that if the issuer has set the asfDisallowIncomingTrustline flag and a user tries to create an offer with CreateOffer but does not have the trustline or a LimitAmount > 0, the error response should be tecNO_LINE

Actual Result

The actual result is that the OfferCreate transaction succeeds.

Environment

Supporting Files

Let us discuss :)

[kohteinaung]

Hi will fine community