It would be nice if we could put erd addresses in Mandos tests and get them correctly encoding.

I guess it consists in modifying the InterpretString method in wasm-vm/mandos-go/expression/interpreter/interpreter.go. If I submit a PR for this, would it have chances to be accepted?

It is theoretically possible.

Are there any examples besides rust or C/C++ ?

Here is a way to reproduce the issue:

https://github.com/gfusee/child-deployed-contract-payable-call-error-demo

The CodeMetadata "Payable By SC" seems to be ignored

It happens with the VM 1.5.25. I never encountered this issue with the VM 1.5.19

You can find the reproduction here: https://github.com/lcswillems/mx-vm-bug

The test passes with vm 1.4.60 but not with 1.4.77.

Has anybody tested whether Hyperledger's Solang https://github.com/hyperledger-labs/solang produces wasm that Arwen can run? Elrond looks fantastic, but incompatibility with Solidity is a bummer.

When the parent contract upgrades its child contract, the transaction doesn't fail but the child contract doesn't have its code changed

Here is a repo that reproduces the issue: https://github.com/gfusee/upgrade-contract-error-demo

This bug happens in both 1.5.19 and the 1.5.25 versions of the VM

Problem

It is frequent that a caller A calls a SC B with a token, the SC B transforms the received token and then send the transformed token back to the caller A.

In the case where the caller A is a SC and the SC B sends back the token with additional data (e.g. self.send().direct(&receiver, &id, &nonce, &amount, b"Some data")), the transaction will fail with the error Not enough gas. You can see a reproduction of the issue here.

We believe that from a developer point of view (if we forget the blockchain implementation details that leads to this error), the transaction should not fail. The additional data should be written in the blockchain and the token should be transferred, but no smart contract call should be done.

Currently, the transaction fails because self.send().direct(..., b"Some data") sends a token to the receiver while setting the gasLimit to 0 and the function name to "Some data". In other words, the blockchain will not only send the token to the receiver but all call the method "Some data" of the receiver. However, because the gasLimit is set to 0, the transaction will necesseraly fail.

Solution

We believe the blockchain should try to call the receiver method only if the receiver is a smart contract, a function name has been specified, and gasLimit > 0.

We made a pull request to fix this: #569

Scenario: mandos/buy.scen.json ... FAIL: unexpected log. Tx purchase-nft. Log index: 0. Log:{
"address": "address:buyer",
"endpoint": "str:internalVMErrors",
"topics": [
"00000000000000006e66742d737761705f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f",
"7075726368617365"
],
"data": "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"
}

Decoded:
/Users/me/elrondsdk/vmtools/v1.4.42/wasm-vm-1.4.42/arwen/contexts/runtime.go:1023 [error signalled by smartcontract] [purchase]
/Users/me/elrondsdk/vmtools/v1.4.42/wasm-vm-1.4.42/arwen/contexts/runtime.go:1023 [error signalled by smartcontract]
/Users/me/elrondsdk/vmtools/v1.4.42/wasm-vm-1.4.42/arwen/contexts/runtime.go:1020 [Not enough supply.]

{
        "step": "scCall",
        "txId": "purchase-nft",
        "tx": {
            "from": "address:buyer",
            "to": "sc:nft-swap",
            "function": "purchase",
			"value": "300",
            "arguments": [
                "1",
				"300"
            ],
            "gasLimit": "20,000,000",
            "gasPrice": "0"
        },
        "expect": {
            "out": [],
            "status": "4",
            "message": "str:Not enough supply.",
            "gas": "*",
            "refund": "*",
			"logs": []
        }
    },

see this multiversx/mx-chain-go#5344

There is probably something wrong in arwen.go:

`arwen-wasm-vm/cmd/test$ go build

# github.com/ElrondNetwork/arwen-wasm-vm/arwen/context
../../arwen/context/arwen.go:189:101: cannot use "uniform_one" (type string) as type *[410]uint32 in argument to wasmer.NewMeteredInstanceWithImports
`

Or I don't know how to build arwen-wasm-vm. Please add howto build it in README.md.Thanks Florian