diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go index 205dc300b0..02b4fa472c 100644 --- a/accounts/abi/abi.go +++ b/accounts/abi/abi.go @@ -74,13 +74,17 @@ func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) { // Unpack output in v according to the abi specification func (abi ABI) Unpack(v interface{}, name string, output []byte) (err error) { - if err = bytesAreProper(output); err != nil { - return err + if len(output) == 0 { + return fmt.Errorf("abi: unmarshalling empty output") } + // since there can't be naming collisions with contracts and events, // we need to decide whether we're calling a method or an event var unpack unpacker if method, ok := abi.Methods[name]; ok { + if len(output)%32 != 0 { + return fmt.Errorf("abi: improperly formatted output") + } unpack = method } else if event, ok := abi.Events[name]; ok { unpack = event diff --git a/accounts/abi/abi_test.go b/accounts/abi/abi_test.go index 79c4d4a163..f2f66986e2 100644 --- a/accounts/abi/abi_test.go +++ b/accounts/abi/abi_test.go @@ -18,6 +18,7 @@ package abi import ( "bytes" + "encoding/hex" "fmt" "log" "math/big" @@ -418,3 +419,43 @@ func TestBareEvents(t *testing.T) { } } } + +// TestUnpackEvent is based on this contract: +// contract T { +// event received(address sender, uint amount, bytes memo); +// function receive(bytes memo) external payable { +// received(msg.sender, msg.value, memo); +// } +// } +// When receive("X") is called with sender 0x00... and value 1, it produces this tx receipt: +// receipt{status=1 cgas=23949 bloom=00000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000040200000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 logs=[log: b6818c8064f645cd82d99b59a1a267d6d61117ef [75fd880d39c1daf53b6547ab6cb59451fc6452d27caa90e5b6649dd8293b9eed] 000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158 9ae378b6d4409eada347a5dc0c180f186cb62dc68fcc0f043425eb917335aa28 0 95d429d309bb9d753954195fe2d69bd140b4ae731b9b5b605c34323de162cf00 0]} +func TestUnpackEvent(t *testing.T) { + const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]` + abi, err := JSON(strings.NewReader(abiJSON)) + if err != nil { + t.Fatal(err) + } + + const hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158` + data, err := hex.DecodeString(hexdata) + if err != nil { + t.Fatal(err) + } + if len(data)%32 == 0 { + t.Errorf("len(data) is %d, want a non-multiple of 32", len(data)) + } + + type ReceivedEvent struct { + Address common.Address + Amount *big.Int + Memo []byte + } + var ev ReceivedEvent + + err = abi.Unpack(&ev, "received", data) + if err != nil { + t.Error(err) + } else { + t.Logf("len(data): %d; received event: %+v", len(data), ev) + } +} diff --git a/accounts/abi/unpack.go b/accounts/abi/unpack.go index 57732797b6..051fc1916f 100644 --- a/accounts/abi/unpack.go +++ b/accounts/abi/unpack.go @@ -203,14 +203,3 @@ func lengthPrefixPointsTo(index int, output []byte) (start int, length int, err //fmt.Printf("LENGTH PREFIX INFO: \nsize: %v\noffset: %v\nstart: %v\n", length, offset, start) return } - -// checks for proper formatting of byte output -func bytesAreProper(output []byte) error { - if len(output) == 0 { - return fmt.Errorf("abi: unmarshalling empty output") - } else if len(output)%32 != 0 { - return fmt.Errorf("abi: improperly formatted output") - } else { - return nil - } -}