From fc520d050aab229b4112de75d5a35585e25475be Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 09:30:38 -0400
Subject: [PATCH 1/7] Add txnas opcodes

---
 cmd/opdoc/opdoc.go                           |   4 +-
 data/transactions/logic/README.md            |   3 +
 data/transactions/logic/TEAL_opcodes.md      |  24 +++++
 data/transactions/logic/assembler.go         |  82 ++++++++++++++-
 data/transactions/logic/assembler_test.go    |  13 ++-
 data/transactions/logic/doc.go               |   9 +-
 data/transactions/logic/eval.go              |  83 +++++++++++++++
 data/transactions/logic/evalStateful_test.go |   3 +
 data/transactions/logic/eval_test.go         | 105 ++++++++++++++++++-
 data/transactions/logic/opcodes.go           |  11 ++
 10 files changed, 327 insertions(+), 10 deletions(-)

diff --git a/cmd/opdoc/opdoc.go b/cmd/opdoc/opdoc.go
index 334942a324..ad1ce4d2d9 100644
--- a/cmd/opdoc/opdoc.go
+++ b/cmd/opdoc/opdoc.go
@@ -238,7 +238,7 @@ func argEnum(name string) []string {
 	if name == "global" {
 		return logic.GlobalFieldNames
 	}
-	if name == "txna" || name == "gtxna" || name == "gtxnsa" {
+	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" {
 		return logic.TxnaFieldNames
 	}
 	if name == "asset_holding_get" {
@@ -282,7 +282,7 @@ func argEnumTypes(name string) string {
 	if name == "global" {
 		return typeString(logic.GlobalFieldTypes)
 	}
-	if name == "txna" || name == "gtxna" || name == "gtxnsa" {
+	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" {
 		return typeString(logic.TxnaFieldTypes)
 	}
 	if name == "asset_holding_get" {
diff --git a/data/transactions/logic/README.md b/data/transactions/logic/README.md
index 75765f00cd..acbac33618 100644
--- a/data/transactions/logic/README.md
+++ b/data/transactions/logic/README.md
@@ -221,6 +221,9 @@ Some of these have immediate data in the byte or bytes after the opcode.
 | `gloads i` | push Ith scratch space index of the Xth transaction in the current group |
 | `gaid t` | push the ID of the asset or application created in the Tth transaction of the current group |
 | `gaids` | push the ID of the asset or application created in the Xth transaction of the current group |
+| `txnas f` | pop an index A. push Ath value of the array field F of the current transaction |
+| `gtxnas t f` | pop an index A. push Ath value of the array field F from the Tth transaction in the current group |
+| `gtxnsas f` | pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group |
 
 **Transaction Fields**
 
diff --git a/data/transactions/logic/TEAL_opcodes.md b/data/transactions/logic/TEAL_opcodes.md
index 70437d2c26..6e70ce9167 100644
--- a/data/transactions/logic/TEAL_opcodes.md
+++ b/data/transactions/logic/TEAL_opcodes.md
@@ -1213,3 +1213,27 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 - Mode: Application
 
 `log` can be called up to MaxLogCalls times in a program, and log up to a total of 1k bytes.
+
+## txnas f
+
+- Opcode: 0xc0 {uint8 transaction field index}
+- Pops: *... stack*, uint64
+- Pushes: any
+- pop an index A. push Ath value of the array field F of the current transaction
+- LogicSigVersion >= 5
+
+## gtxnas t f
+
+- Opcode: 0xc1 {uint8 transaction group index} {uint8 transaction field index}
+- Pops: *... stack*, uint64
+- Pushes: any
+- pop an index A. push Ath value of the array field F from the Tth transaction in the current group
+- LogicSigVersion >= 5
+
+## gtxnsas f
+
+- Opcode: 0xc2 {uint8 transaction field index}
+- Pops: *... stack*, {uint64 A}, {uint64 B}
+- Pushes: any
+- pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group
+- LogicSigVersion >= 5
diff --git a/data/transactions/logic/assembler.go b/data/transactions/logic/assembler.go
index 129cfe7b2c..4db9ebe15b 100644
--- a/data/transactions/logic/assembler.go
+++ b/data/transactions/logic/assembler.go
@@ -816,7 +816,7 @@ func assembleTxn2(ops *OpStream, spec *OpSpec, args []string) error {
 
 func assembleTxna(ops *OpStream, spec *OpSpec, args []string) error {
 	if len(args) != 2 {
-		return ops.error("txna expects two arguments")
+		return ops.error("txna expects two immediate arguments")
 	}
 	fs, ok := txnFieldSpecByName[args[0]]
 	if !ok {
@@ -844,6 +844,28 @@ func assembleTxna(ops *OpStream, spec *OpSpec, args []string) error {
 	return nil
 }
 
+func assembleTxnas(ops *OpStream, spec *OpSpec, args []string) error {
+	if len(args) != 1 {
+		return ops.error("txnas expects one immediate argument")
+	}
+	fs, ok := txnFieldSpecByName[args[0]]
+	if !ok {
+		return ops.errorf("txnas unknown field: %#v", args[0])
+	}
+	_, ok = txnaFieldSpecByField[fs.field]
+	if !ok {
+		return ops.errorf("txnas unknown field: %#v", args[0])
+	}
+	if fs.version > ops.Version {
+		return ops.errorf("txnas %#v available in version %d. Missed #pragma version?", args[0], fs.version)
+	}
+
+	ops.pending.WriteByte(spec.Opcode)
+	ops.pending.WriteByte(uint8(fs.field))
+	ops.returns(fs.ftype)
+	return nil
+}
+
 func assembleGtxn(ops *OpStream, spec *OpSpec, args []string) error {
 	if len(args) != 2 {
 		return ops.error("gtxn expects two arguments")
@@ -925,6 +947,38 @@ func assembleGtxna(ops *OpStream, spec *OpSpec, args []string) error {
 	return nil
 }
 
+func assembleGtxnas(ops *OpStream, spec *OpSpec, args []string) error {
+	if len(args) != 2 {
+		return ops.error("gtxnas expects two immediate arguments")
+	}
+
+	slot, err := strconv.ParseUint(args[0], 0, 64)
+	if err != nil {
+		return ops.error(err)
+	}
+	if slot > 255 {
+		return ops.errorf("gtxnas group index beyond 255: %d", slot)
+	}
+
+	fs, ok := txnFieldSpecByName[args[1]]
+	if !ok {
+		return ops.errorf("gtxnas unknown field: %#v", args[1])
+	}
+	_, ok = txnaFieldSpecByField[fs.field]
+	if !ok {
+		return ops.errorf("gtxnas unknown field: %#v", args[1])
+	}
+	if fs.version > ops.Version {
+		return ops.errorf("gtxnas %#v available in version %d. Missed #pragma version?", args[1], fs.version)
+	}
+
+	ops.pending.WriteByte(spec.Opcode)
+	ops.pending.WriteByte(uint8(slot))
+	ops.pending.WriteByte(uint8(fs.field))
+	ops.returns(fs.ftype)
+	return nil
+}
+
 func assembleGtxns(ops *OpStream, spec *OpSpec, args []string) error {
 	if len(args) == 2 {
 		gtxnsa := OpsByName[ops.Version]["gtxnsa"]
@@ -980,6 +1034,27 @@ func assembleGtxnsa(ops *OpStream, spec *OpSpec, args []string) error {
 	return nil
 }
 
+func assembleGtxnsas(ops *OpStream, spec *OpSpec, args []string) error {
+	if len(args) != 1 {
+		return ops.error("gtxnsas expects one immediate argument")
+	}
+	fs, ok := txnFieldSpecByName[args[0]]
+	if !ok {
+		return ops.errorf("gtxnsas unknown field: %#v", args[0])
+	}
+	_, ok = txnaFieldSpecByField[fs.field]
+	if !ok {
+		return ops.errorf("gtxnsas unknown field: %#v", args[0])
+	}
+	if fs.version > ops.Version {
+		return ops.errorf("gtxnsas %#v available in version %d. Missed #pragma version?", args[0], fs.version)
+	}
+	ops.pending.WriteByte(spec.Opcode)
+	ops.pending.WriteByte(uint8(fs.field))
+	ops.returns(fs.ftype)
+	return nil
+}
+
 func assembleGlobal(ops *OpStream, spec *OpSpec, args []string) error {
 	if len(args) != 1 {
 		return ops.errorf("%s expects one argument", spec.Name)
@@ -2294,7 +2369,7 @@ func checkPushBytes(cx *evalContext) error {
 	return cx.err
 }
 
-// This is also used to disassemble gtxns
+// This is also used to disassemble gtxns, gtxnsas and txnas
 func disTxn(dis *disassembleState, spec *OpSpec) (string, error) {
 	lastIdx := dis.pc + 1
 	if len(dis.program) <= lastIdx {
@@ -2325,6 +2400,7 @@ func disTxna(dis *disassembleState, spec *OpSpec) (string, error) {
 	return fmt.Sprintf("%s %s %d", spec.Name, TxnFieldNames[txarg], arrayFieldIdx), nil
 }
 
+// This is also used to disassemble gtxnas
 func disGtxn(dis *disassembleState, spec *OpSpec) (string, error) {
 	lastIdx := dis.pc + 2
 	if len(dis.program) <= lastIdx {
@@ -2337,7 +2413,7 @@ func disGtxn(dis *disassembleState, spec *OpSpec) (string, error) {
 	if int(txarg) >= len(TxnFieldNames) {
 		return "", fmt.Errorf("invalid txn arg index %d at pc=%d", txarg, dis.pc)
 	}
-	return fmt.Sprintf("gtxn %d %s", gi, TxnFieldNames[txarg]), nil
+	return fmt.Sprintf("%s %d %s", spec.Name, gi, TxnFieldNames[txarg]), nil
 }
 
 func disGtxna(dis *disassembleState, spec *OpSpec) (string, error) {
diff --git a/data/transactions/logic/assembler_test.go b/data/transactions/logic/assembler_test.go
index 82d2e6af9a..0e3b640286 100644
--- a/data/transactions/logic/assembler_test.go
+++ b/data/transactions/logic/assembler_test.go
@@ -312,6 +312,13 @@ extract16bits
 log
 txn Nonparticipation
 gtxn 0 Nonparticipation
+int 1
+txnas ApplicationArgs
+int 0
+gtxnas 0 ApplicationArgs
+int 0
+int 0
+gtxnsas ApplicationArgs
 `
 
 var nonsense = map[uint64]string{
@@ -327,7 +334,7 @@ var compiled = map[uint64]string{
 	2: "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",
 	3: "032008b7a60cf8acd19181cf959a12f8acd19181cf951af8acd19181cf15f8acd191810f01020026050212340c68656c6c6f20776f726c6421208dae2087fbba51304eb02b91f656948397a7946390e8cb70fc9ea4d95f92251d024242047465737400320032013202320328292929292a0431003101310231043105310731083109310a310b310c310d310e310f3111311231133114311533000033000133000233000433000533000733000833000933000a33000b33000c33000d33000e33000f3300113300123300133300143300152d2e0102222324252104082209240a220b230c240d250e230f23102311231223132314181b1c2b171615400003290349483403350222231d4a484848482a50512a63222352410003420000432105602105612105270463484821052b62482b642b65484821052b2106662b21056721072b682b692107210570004848210771004848361c0037001a0031183119311b311d311e311f3120210721051e312131223123312431253126312731283129312a312b312c312d312e312f4478222105531421055427042106552105082106564c4d4b02210538212106391c0081e80780046a6f686e",
 	4: "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",
-	5: "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",
+	5: "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",
 }
 
 func pseudoOp(opcode string) bool {
@@ -494,13 +501,15 @@ func TestAssembleTxna(t *testing.T) {
 	testLine(t, "gtxna 0 Sender 256", AssemblerMaxVersion, "gtxna unknown field: \"Sender\"")
 	testLine(t, "txn Accounts 0", 1, "txn expects one argument")
 	testLine(t, "txn Accounts 0 1", 2, "txn expects one or two arguments")
-	testLine(t, "txna Accounts 0 1", AssemblerMaxVersion, "txna expects two arguments")
+	testLine(t, "txna Accounts 0 1", AssemblerMaxVersion, "txna expects two immediate arguments")
+	testLine(t, "txnas Accounts 1", AssemblerMaxVersion, "txnas expects one immediate argument")
 	testLine(t, "txna Accounts a", AssemblerMaxVersion, "strconv.ParseUint...")
 	testLine(t, "gtxn 0 Sender 0", 1, "gtxn expects two arguments")
 	testLine(t, "gtxn 0 Sender 1 2", 2, "gtxn expects two or three arguments")
 	testLine(t, "gtxna 0 Accounts 1 2", AssemblerMaxVersion, "gtxna expects three arguments")
 	testLine(t, "gtxna a Accounts 0", AssemblerMaxVersion, "strconv.ParseUint...")
 	testLine(t, "gtxna 0 Accounts a", AssemblerMaxVersion, "strconv.ParseUint...")
+	testLine(t, "gtxnas Accounts 1 2", AssemblerMaxVersion, "gtxnas expects two immediate arguments")
 	testLine(t, "txn ABC", 2, "txn unknown field: \"ABC\"")
 	testLine(t, "gtxn 0 ABC", 2, "gtxn unknown field: \"ABC\"")
 	testLine(t, "gtxn a ABC", 2, "strconv.ParseUint...")
diff --git a/data/transactions/logic/doc.go b/data/transactions/logic/doc.go
index 27d2963a4a..05be72e680 100644
--- a/data/transactions/logic/doc.go
+++ b/data/transactions/logic/doc.go
@@ -152,6 +152,10 @@ var opDocByName = map[string]string{
 	"b~":  "X with all bits inverted",
 
 	"log": "write bytes to log state of the current application",
+
+	"txnas":   "pop an index A. push Ath value of the array field F of the current transaction",
+	"gtxnas":  "pop an index A. push Ath value of the array field F from the Tth transaction in the current group",
+	"gtxnsas": "pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group",
 }
 
 // OpDoc returns a description of the op
@@ -191,6 +195,9 @@ var opcodeImmediateNotes = map[string]string{
 	"asset_holding_get": "{uint8 asset holding field index}",
 	"asset_params_get":  "{uint8 asset params field index}",
 	"app_params_get":    "{uint8 app params field index}",
+	"txnas":             "{uint8 transaction field index}",
+	"gtxnas":            "{uint8 transaction group index} {uint8 transaction field index}",
+	"gtxnsas":           "{uint8 transaction field index}",
 }
 
 // OpImmediateNote returns a short string about immediate data which follows the op byte
@@ -252,7 +259,7 @@ var OpGroups = map[string][]string{
 	"Byte Array Slicing":   {"substring", "substring3", "extract", "extract3", "extract16bits", "extract32bits", "extract64bits"},
 	"Byteslice Arithmetic": {"b+", "b-", "b/", "b*", "b<", "b>", "b<=", "b>=", "b==", "b!=", "b%"},
 	"Byteslice Logic":      {"b|", "b&", "b^", "b~"},
-	"Loading Values":       {"intcblock", "intc", "intc_0", "intc_1", "intc_2", "intc_3", "pushint", "bytecblock", "bytec", "bytec_0", "bytec_1", "bytec_2", "bytec_3", "pushbytes", "bzero", "arg", "arg_0", "arg_1", "arg_2", "arg_3", "txn", "gtxn", "txna", "gtxna", "gtxns", "gtxnsa", "global", "load", "store", "gload", "gloads", "gaid", "gaids"},
+	"Loading Values":       {"intcblock", "intc", "intc_0", "intc_1", "intc_2", "intc_3", "pushint", "bytecblock", "bytec", "bytec_0", "bytec_1", "bytec_2", "bytec_3", "pushbytes", "bzero", "arg", "arg_0", "arg_1", "arg_2", "arg_3", "txn", "gtxn", "txna", "gtxna", "gtxns", "gtxnsa", "global", "load", "store", "gload", "gloads", "gaid", "gaids", "txnas", "gtxnas", "gtxnsas"},
 	"Flow Control":         {"err", "bnz", "bz", "b", "return", "pop", "dup", "dup2", "dig", "cover", "uncover", "swap", "select", "assert", "callsub", "retsub"},
 	"State Access":         {"balance", "min_balance", "app_opted_in", "app_local_get", "app_local_get_ex", "app_global_get", "app_global_get_ex", "app_local_put", "app_global_put", "app_local_del", "app_global_del", "asset_holding_get", "asset_params_get", "app_params_get", "log"},
 }
diff --git a/data/transactions/logic/eval.go b/data/transactions/logic/eval.go
index de56fa2850..085a46e07b 100644
--- a/data/transactions/logic/eval.go
+++ b/data/transactions/logic/eval.go
@@ -2062,6 +2062,29 @@ func opTxna(cx *evalContext) {
 	cx.stack = append(cx.stack, sv)
 }
 
+func opTxnas(cx *evalContext) {
+	last := len(cx.stack) - 1
+
+	field := TxnField(uint64(cx.program[cx.pc+1]))
+	fs, ok := txnFieldSpecByField[field]
+	if !ok || fs.version > cx.version {
+		cx.err = fmt.Errorf("invalid txn field %d", field)
+		return
+	}
+	_, ok = txnaFieldSpecByField[field]
+	if !ok {
+		cx.err = fmt.Errorf("txnas unsupported field %d", field)
+		return
+	}
+	arrayFieldIdx := cx.stack[last].Uint
+	sv, err := cx.txnFieldToStack(&cx.Txn.Txn, field, arrayFieldIdx, cx.GroupIndex)
+	if err != nil {
+		cx.err = err
+		return
+	}
+	cx.stack[last] = sv
+}
+
 func opGtxn(cx *evalContext) {
 	gtxid := int(uint(cx.program[cx.pc+1]))
 	if gtxid >= len(cx.TxnGroup) {
@@ -2122,6 +2145,35 @@ func opGtxna(cx *evalContext) {
 	cx.stack = append(cx.stack, sv)
 }
 
+func opGtxnas(cx *evalContext) {
+	last := len(cx.stack) - 1
+
+	gtxid := int(uint(cx.program[cx.pc+1]))
+	if gtxid >= len(cx.TxnGroup) {
+		cx.err = fmt.Errorf("gtxnas lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
+		return
+	}
+	tx := &cx.TxnGroup[gtxid].Txn
+	field := TxnField(uint64(cx.program[cx.pc+2]))
+	fs, ok := txnFieldSpecByField[field]
+	if !ok || fs.version > cx.version {
+		cx.err = fmt.Errorf("invalid txn field %d", field)
+		return
+	}
+	_, ok = txnaFieldSpecByField[field]
+	if !ok {
+		cx.err = fmt.Errorf("gtxnas unsupported field %d", field)
+		return
+	}
+	arrayFieldIdx := cx.stack[last].Uint
+	sv, err := cx.txnFieldToStack(tx, field, arrayFieldIdx, gtxid)
+	if err != nil {
+		cx.err = err
+		return
+	}
+	cx.stack[last] = sv
+}
+
 func opGtxns(cx *evalContext) {
 	last := len(cx.stack) - 1
 	gtxid := int(cx.stack[last].Uint)
@@ -2184,6 +2236,37 @@ func opGtxnsa(cx *evalContext) {
 	cx.stack[last] = sv
 }
 
+func opGtxnsas(cx *evalContext) {
+	last := len(cx.stack) - 1
+	prev := last - 1
+
+	gtxid := int(cx.stack[prev].Uint)
+	if gtxid >= len(cx.TxnGroup) {
+		cx.err = fmt.Errorf("gtxnsa lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
+		return
+	}
+	tx := &cx.TxnGroup[gtxid].Txn
+	field := TxnField(uint64(cx.program[cx.pc+1]))
+	fs, ok := txnFieldSpecByField[field]
+	if !ok || fs.version > cx.version {
+		cx.err = fmt.Errorf("invalid txn field %d", field)
+		return
+	}
+	_, ok = txnaFieldSpecByField[field]
+	if !ok {
+		cx.err = fmt.Errorf("gtxnsa unsupported field %d", field)
+		return
+	}
+	arrayFieldIdx := cx.stack[last].Uint
+	sv, err := cx.txnFieldToStack(tx, field, arrayFieldIdx, gtxid)
+	if err != nil {
+		cx.err = err
+		return
+	}
+	cx.stack[prev] = sv
+	cx.stack = cx.stack[:last]
+}
+
 func opGaidImpl(cx *evalContext, groupIdx int, opName string) (sv stackValue, err error) {
 	if groupIdx >= len(cx.TxnGroup) {
 		err = fmt.Errorf("%s lookup TxnGroup[%d] but it only has %d", opName, groupIdx, len(cx.TxnGroup))
diff --git a/data/transactions/logic/evalStateful_test.go b/data/transactions/logic/evalStateful_test.go
index f782fcce9a..8aa10f2f13 100644
--- a/data/transactions/logic/evalStateful_test.go
+++ b/data/transactions/logic/evalStateful_test.go
@@ -2843,6 +2843,9 @@ func TestReturnTypes(t *testing.T) {
 		"pushbytes":         `pushbytes "jojogoodgorilla"`,
 		"app_params_get":    "app_params_get AppGlobalNumUint",
 		"extract":           "extract 0 2",
+		"txnas":             "txnas ApplicationArgs",
+		"gtxnas":            "gtxnas 0 ApplicationArgs",
+		"gtxnsas":           "pop; pop; int 0; int 0; gtxnsas ApplicationArgs",
 	}
 
 	byName := OpsByName[LogicVersion]
diff --git a/data/transactions/logic/eval_test.go b/data/transactions/logic/eval_test.go
index 98587f5ba2..2ddde9660d 100644
--- a/data/transactions/logic/eval_test.go
+++ b/data/transactions/logic/eval_test.go
@@ -1422,6 +1422,14 @@ txn Nonparticipation
 pop
 int 1
 ==
+assert
+txn ConfigAssetMetadataHash
+int 2
+txnas ApplicationArgs
+==
+assert
+
+int 1
 `
 
 func makeSampleTxn() transactions.SignedTxn {
@@ -1788,7 +1796,7 @@ int 1
 ==
 &&
 `
-	gtxnText := gtxnTextV2 + ` gtxn 0 ExtraProgramPages
+	gtxnTextV4 := gtxnTextV2 + ` gtxn 0 ExtraProgramPages
 int 0
 ==
 &&
@@ -1796,12 +1804,26 @@ gtxn 1 ExtraProgramPages
 int 2
 ==
 &&
+`
+
+	gtxnText := gtxnTextV4 + `int 0
+gtxnas 0 Accounts
+gtxn 0 Sender
+==
+&&
+int 0
+int 0
+gtxnsas Accounts
+gtxn 0 Sender
+==
+&&
 `
 
 	tests := map[uint64]string{
 		1: gtxnTextV1,
 		2: gtxnTextV2,
-		4: gtxnText,
+		4: gtxnTextV4,
+		5: gtxnText,
 	}
 
 	for v, source := range tests {
@@ -2034,6 +2056,85 @@ global ZeroAddress
 	require.True(t, pass)
 }
 
+func TestTxnas(t *testing.T) {
+	partitiontest.PartitionTest(t)
+
+	t.Parallel()
+
+	source := `int 1
+txnas Accounts
+int 0
+txnas ApplicationArgs
+==
+`
+	ops := testProg(t, source, AssemblerMaxVersion)
+	var txn transactions.SignedTxn
+	txn.Txn.Accounts = make([]basics.Address, 1)
+	txn.Txn.Accounts[0] = txn.Txn.Sender
+	txn.Txn.ApplicationArgs = make([][]byte, 1)
+	txn.Txn.ApplicationArgs[0] = []byte(protocol.PaymentTx)
+	txgroup := make([]transactions.SignedTxn, 1)
+	txgroup[0] = txn
+	ep := defaultEvalParams(nil, &txn)
+	ep.TxnGroup = txgroup
+	_, err := Eval(ops.Program, ep)
+	require.NoError(t, err)
+
+	// check special case: Account 0 == Sender
+	// even without any additional context
+	source = `int 0
+txnas Accounts
+txn Sender
+==
+`
+	ops2 := testProg(t, source, AssemblerMaxVersion)
+	var txn2 transactions.SignedTxn
+	copy(txn2.Txn.Sender[:], []byte("aoeuiaoeuiaoeuiaoeuiaoeuiaoeui00"))
+	ep2 := defaultEvalParams(nil, &txn2)
+	pass, err := Eval(ops2.Program, ep2)
+	require.NoError(t, err)
+	require.True(t, pass)
+
+	// check gtxnas
+	source = `int 1
+gtxnas 0 Accounts
+txna ApplicationArgs 0
+==`
+	ops = testProg(t, source, AssemblerMaxVersion)
+	require.NoError(t, err)
+	_, err = Eval(ops.Program, ep)
+	require.NoError(t, err)
+
+	// check special case: Account 0 == Sender
+	// even without any additional context
+	source = `int 0
+gtxnas 0 Accounts
+txn Sender
+==
+	`
+	ops3 := testProg(t, source, AssemblerMaxVersion)
+	var txn3 transactions.SignedTxn
+	copy(txn2.Txn.Sender[:], []byte("aoeuiaoeuiaoeuiaoeuiaoeuiaoeui00"))
+	txgroup3 := make([]transactions.SignedTxn, 1)
+	txgroup3[0] = txn3
+	ep3 := defaultEvalParams(nil, &txn3)
+	ep3.TxnGroup = txgroup3
+	pass, err = Eval(ops3.Program, ep3)
+	require.NoError(t, err)
+	require.True(t, pass)
+
+	// check gtxnsas
+	source = `int 0
+int 1
+gtxnsas Accounts
+txna ApplicationArgs 0
+==`
+	ops = testProg(t, source, AssemblerMaxVersion)
+	require.NoError(t, err)
+	_, err = Eval(ops.Program, ep)
+	require.NoError(t, err)
+}
+
 func TestBitOps(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
diff --git a/data/transactions/logic/opcodes.go b/data/transactions/logic/opcodes.go
index 2ab59ed9c4..edbe2b6b72 100644
--- a/data/transactions/logic/opcodes.go
+++ b/data/transactions/logic/opcodes.go
@@ -298,6 +298,17 @@ var OpSpecs = []OpSpec{
 
 	// ABI support opcodes.
 	{0xb0, "log", opLog, asmDefault, disDefault, oneBytes, nil, 5, runModeApplication, opDefault},
+
+	// {0x36, "txna", opTxna, assembleTxna, disTxna, nil, oneAny, 2, modeAny, immediates("f", "i")},
+	// {0x37, "gtxna", opGtxna, assembleGtxna, disGtxna, nil, oneAny, 2, modeAny, immediates("t", "f", "i")},
+	// // Like gtxn, but gets txn index from stack, rather than immediate arg
+	// {0x38, "gtxns", opGtxns, assembleGtxns, disTxn, oneInt, oneAny, 3, modeAny, immediates("f")},
+	// {0x39, "gtxnsa", opGtxnsa, assembleGtxns, disTxna, oneInt, oneAny, 3, modeAny, immediates("f", "i")},
+
+	// Dynamically indexing into LogicSigs
+	{0xc0, "txnas", opTxnas, assembleTxnas, disTxn, oneInt, oneAny, 5, modeAny, immediates("f")},
+	{0xc1, "gtxnas", opGtxnas, assembleGtxnas, disGtxn, oneInt, oneAny, 5, modeAny, immediates("t", "f")},
+	{0xc2, "gtxnsas", opGtxnsas, assembleGtxnsas, disTxn, twoInts, oneAny, 5, modeAny, immediates("f")},
 }
 
 type sortByOpcode []OpSpec

From f37928bb31e27aa29ec9b503c26fcfe2cd3102bd Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 09:34:25 -0400
Subject: [PATCH 2/7] Delete comments

---
 data/transactions/logic/opcodes.go | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/data/transactions/logic/opcodes.go b/data/transactions/logic/opcodes.go
index edbe2b6b72..fba221b59e 100644
--- a/data/transactions/logic/opcodes.go
+++ b/data/transactions/logic/opcodes.go
@@ -299,12 +299,6 @@ var OpSpecs = []OpSpec{
 	// ABI support opcodes.
 	{0xb0, "log", opLog, asmDefault, disDefault, oneBytes, nil, 5, runModeApplication, opDefault},
 
-	// {0x36, "txna", opTxna, assembleTxna, disTxna, nil, oneAny, 2, modeAny, immediates("f", "i")},
-	// {0x37, "gtxna", opGtxna, assembleGtxna, disGtxna, nil, oneAny, 2, modeAny, immediates("t", "f", "i")},
-	// // Like gtxn, but gets txn index from stack, rather than immediate arg
-	// {0x38, "gtxns", opGtxns, assembleGtxns, disTxn, oneInt, oneAny, 3, modeAny, immediates("f")},
-	// {0x39, "gtxnsa", opGtxnsa, assembleGtxns, disTxna, oneInt, oneAny, 3, modeAny, immediates("f", "i")},
-
 	// Dynamically indexing into LogicSigs
 	{0xc0, "txnas", opTxnas, assembleTxnas, disTxn, oneInt, oneAny, 5, modeAny, immediates("f")},
 	{0xc1, "gtxnas", opGtxnas, assembleGtxnas, disGtxn, oneInt, oneAny, 5, modeAny, immediates("t", "f")},

From bb2cbf64e43c3a9989ffc445d0cb881fa159c38d Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 11:10:32 -0400
Subject: [PATCH 3/7] Add args opcode

---
 data/transactions/logic/README.md            |  1 +
 data/transactions/logic/TEAL_opcodes.md      |  9 ++++++++
 data/transactions/logic/assembler_test.go    |  4 +++-
 data/transactions/logic/doc.go               |  3 ++-
 data/transactions/logic/eval.go              |  7 +++++++
 data/transactions/logic/evalStateful_test.go |  1 +
 data/transactions/logic/eval_test.go         | 22 +++++++++-----------
 data/transactions/logic/opcodes.go           |  1 +
 8 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/data/transactions/logic/README.md b/data/transactions/logic/README.md
index acbac33618..c2df18c6d7 100644
--- a/data/transactions/logic/README.md
+++ b/data/transactions/logic/README.md
@@ -224,6 +224,7 @@ Some of these have immediate data in the byte or bytes after the opcode.
 | `txnas f` | pop an index A. push Ath value of the array field F of the current transaction |
 | `gtxnas t f` | pop an index A. push Ath value of the array field F from the Tth transaction in the current group |
 | `gtxnsas f` | pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group |
+| `args` | push Xth LogicSig argument to stack |
 
 **Transaction Fields**
 
diff --git a/data/transactions/logic/TEAL_opcodes.md b/data/transactions/logic/TEAL_opcodes.md
index 6e70ce9167..8428e27f08 100644
--- a/data/transactions/logic/TEAL_opcodes.md
+++ b/data/transactions/logic/TEAL_opcodes.md
@@ -1237,3 +1237,12 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 - Pushes: any
 - pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group
 - LogicSigVersion >= 5
+
+## args
+
+- Opcode: 0xc3
+- Pops: *... stack*, uint64
+- Pushes: []byte
+- push Xth LogicSig argument to stack
+- LogicSigVersion >= 5
+- Mode: Signature
diff --git a/data/transactions/logic/assembler_test.go b/data/transactions/logic/assembler_test.go
index 0e3b640286..cd53569392 100644
--- a/data/transactions/logic/assembler_test.go
+++ b/data/transactions/logic/assembler_test.go
@@ -319,6 +319,8 @@ gtxnas 0 ApplicationArgs
 int 0
 int 0
 gtxnsas ApplicationArgs
+int 0
+args
 `
 
 var nonsense = map[uint64]string{
@@ -334,7 +336,7 @@ var compiled = map[uint64]string{
 	2: "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",
 	3: "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",
 	4: "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",
-	5: "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",
+	5: "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",
 }
 
 func pseudoOp(opcode string) bool {
diff --git a/data/transactions/logic/doc.go b/data/transactions/logic/doc.go
index 05be72e680..9700675d01 100644
--- a/data/transactions/logic/doc.go
+++ b/data/transactions/logic/doc.go
@@ -156,6 +156,7 @@ var opDocByName = map[string]string{
 	"txnas":   "pop an index A. push Ath value of the array field F of the current transaction",
 	"gtxnas":  "pop an index A. push Ath value of the array field F from the Tth transaction in the current group",
 	"gtxnsas": "pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group",
+	"args":    "push Xth LogicSig argument to stack",
 }
 
 // OpDoc returns a description of the op
@@ -259,7 +260,7 @@ var OpGroups = map[string][]string{
 	"Byte Array Slicing":   {"substring", "substring3", "extract", "extract3", "extract16bits", "extract32bits", "extract64bits"},
 	"Byteslice Arithmetic": {"b+", "b-", "b/", "b*", "b<", "b>", "b<=", "b>=", "b==", "b!=", "b%"},
 	"Byteslice Logic":      {"b|", "b&", "b^", "b~"},
-	"Loading Values":       {"intcblock", "intc", "intc_0", "intc_1", "intc_2", "intc_3", "pushint", "bytecblock", "bytec", "bytec_0", "bytec_1", "bytec_2", "bytec_3", "pushbytes", "bzero", "arg", "arg_0", "arg_1", "arg_2", "arg_3", "txn", "gtxn", "txna", "gtxna", "gtxns", "gtxnsa", "global", "load", "store", "gload", "gloads", "gaid", "gaids", "txnas", "gtxnas", "gtxnsas"},
+	"Loading Values":       {"intcblock", "intc", "intc_0", "intc_1", "intc_2", "intc_3", "pushint", "bytecblock", "bytec", "bytec_0", "bytec_1", "bytec_2", "bytec_3", "pushbytes", "bzero", "arg", "arg_0", "arg_1", "arg_2", "arg_3", "txn", "gtxn", "txna", "gtxna", "gtxns", "gtxnsa", "global", "load", "store", "gload", "gloads", "gaid", "gaids", "txnas", "gtxnas", "gtxnsas", "args"},
 	"Flow Control":         {"err", "bnz", "bz", "b", "return", "pop", "dup", "dup2", "dig", "cover", "uncover", "swap", "select", "assert", "callsub", "retsub"},
 	"State Access":         {"balance", "min_balance", "app_opted_in", "app_local_get", "app_local_get_ex", "app_global_get", "app_global_get_ex", "app_local_put", "app_global_put", "app_local_del", "app_global_del", "asset_holding_get", "asset_params_get", "app_params_get", "log"},
 }
diff --git a/data/transactions/logic/eval.go b/data/transactions/logic/eval.go
index 085a46e07b..b0d8542a3e 100644
--- a/data/transactions/logic/eval.go
+++ b/data/transactions/logic/eval.go
@@ -1598,6 +1598,13 @@ func opArg2(cx *evalContext) {
 func opArg3(cx *evalContext) {
 	opArgN(cx, 3)
 }
+func opArgs(cx *evalContext) {
+	last := len(cx.stack) - 1
+	n := cx.stack[last].Uint
+	// Pop the index and push the result back on the stack.
+	cx.stack = cx.stack[:last]
+	opArgN(cx, n)
+}
 
 func branchTarget(cx *evalContext) (int, error) {
 	offset := int16(uint16(cx.program[cx.pc+1])<<8 | uint16(cx.program[cx.pc+2]))
diff --git a/data/transactions/logic/evalStateful_test.go b/data/transactions/logic/evalStateful_test.go
index 8aa10f2f13..931e76bb77 100644
--- a/data/transactions/logic/evalStateful_test.go
+++ b/data/transactions/logic/evalStateful_test.go
@@ -2846,6 +2846,7 @@ func TestReturnTypes(t *testing.T) {
 		"txnas":             "txnas ApplicationArgs",
 		"gtxnas":            "gtxnas 0 ApplicationArgs",
 		"gtxnsas":           "pop; pop; int 0; int 0; gtxnsas ApplicationArgs",
+		"args":              "args",
 	}
 
 	byName := OpsByName[LogicVersion]
diff --git a/data/transactions/logic/eval_test.go b/data/transactions/logic/eval_test.go
index 2ddde9660d..ecd92b15a0 100644
--- a/data/transactions/logic/eval_test.go
+++ b/data/transactions/logic/eval_test.go
@@ -905,18 +905,11 @@ func TestArg(t *testing.T) {
 	t.Parallel()
 	for v := uint64(1); v <= AssemblerMaxVersion; v++ {
 		t.Run(fmt.Sprintf("v=%d", v), func(t *testing.T) {
-			ops := testProg(t, `arg 0
-arg 1
-==
-arg 2
-arg 3
-!=
-&&
-arg 4
-len
-int 9
-<
-&&`, v)
+			source := "arg 0; arg 1; ==; arg 2; arg 3; !=; &&; arg 4; len; int 9; <; &&;"
+			if v >= 5 {
+				source += "int 0; args; int 1; args; ==; assert;"
+			}
+			ops := testProg(t, source, v)
 			err := Check(ops.Program, defaultEvalParams(nil, nil))
 			require.NoError(t, err)
 			var txn transactions.SignedTxn
@@ -1428,6 +1421,11 @@ int 2
 txnas ApplicationArgs
 ==
 assert
+txn Sender
+int 0
+args
+==
+assert
 
 int 1
 `
diff --git a/data/transactions/logic/opcodes.go b/data/transactions/logic/opcodes.go
index fba221b59e..d56d1b4b27 100644
--- a/data/transactions/logic/opcodes.go
+++ b/data/transactions/logic/opcodes.go
@@ -303,6 +303,7 @@ var OpSpecs = []OpSpec{
 	{0xc0, "txnas", opTxnas, assembleTxnas, disTxn, oneInt, oneAny, 5, modeAny, immediates("f")},
 	{0xc1, "gtxnas", opGtxnas, assembleGtxnas, disGtxn, oneInt, oneAny, 5, modeAny, immediates("t", "f")},
 	{0xc2, "gtxnsas", opGtxnsas, assembleGtxnsas, disTxn, twoInts, oneAny, 5, modeAny, immediates("f")},
+	{0xc3, "args", opArgs, asmDefault, disDefault, oneInt, oneBytes, 5, runModeSignature, opDefault},
 }
 
 type sortByOpcode []OpSpec

From 1cb18d5e8a5f3699f5a9a1f37f5ebb3020c4f21a Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 11:50:24 -0400
Subject: [PATCH 4/7] Address PR comments

---
 data/transactions/logic/TEAL_opcodes.md | 56 ++++++++++++-------------
 data/transactions/logic/eval.go         | 10 ++++-
 data/transactions/logic/eval_test.go    |  4 +-
 3 files changed, 37 insertions(+), 33 deletions(-)

diff --git a/data/transactions/logic/TEAL_opcodes.md b/data/transactions/logic/TEAL_opcodes.md
index eb051a5cd8..01f5909410 100644
--- a/data/transactions/logic/TEAL_opcodes.md
+++ b/data/transactions/logic/TEAL_opcodes.md
@@ -1217,7 +1217,33 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 
 `log` can be called up to MaxLogCalls times in a program, and log up to a total of 1k bytes.
 
-<<<<<<< HEAD
+## tx_begin
+
+- Opcode: 0xb1
+- Pops: _None_
+- Pushes: _None_
+- Prepare a new application action
+- LogicSigVersion >= 5
+- Mode: Application
+
+## tx_field f
+
+- Opcode: 0xb2 {uint8 transaction field index}
+- Pops: *... stack*, any
+- Pushes: _None_
+- Set field F of the current application action
+- LogicSigVersion >= 5
+- Mode: Application
+
+## tx_submit
+
+- Opcode: 0xb3
+- Pops: _None_
+- Pushes: _None_
+- Execute the current application action. Panic on any failure.
+- LogicSigVersion >= 5
+- Mode: Application
+
 ## txnas f
 
 - Opcode: 0xc0 {uint8 transaction field index}
@@ -1250,31 +1276,3 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 - push Xth LogicSig argument to stack
 - LogicSigVersion >= 5
 - Mode: Signature
-=======
-## tx_begin
-
-- Opcode: 0xb1
-- Pops: _None_
-- Pushes: _None_
-- Prepare a new application action
-- LogicSigVersion >= 5
-- Mode: Application
-
-## tx_field f
-
-- Opcode: 0xb2 {uint8 transaction field index}
-- Pops: *... stack*, any
-- Pushes: _None_
-- Set field F of the current application action
-- LogicSigVersion >= 5
-- Mode: Application
-
-## tx_submit
-
-- Opcode: 0xb3
-- Pops: _None_
-- Pushes: _None_
-- Execute the current application action. Panic on any failure.
-- LogicSigVersion >= 5
-- Mode: Application
->>>>>>> cd832b3c85fdc2ad3d98593b49cbe34b7a6dfc2a
diff --git a/data/transactions/logic/eval.go b/data/transactions/logic/eval.go
index 3ae2320cfd..4c88b83bf6 100644
--- a/data/transactions/logic/eval.go
+++ b/data/transactions/logic/eval.go
@@ -2170,6 +2170,9 @@ func opGtxnas(cx *EvalContext) {
 	if gtxid >= len(cx.TxnGroup) {
 		cx.err = fmt.Errorf("gtxnas lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
 		return
+	} else if gtxid < 0 {
+		cx.err = fmt.Errorf("gtxnas lookup %d cannot be negative", gtxid)
+		return
 	}
 	tx := &cx.TxnGroup[gtxid].Txn
 	field := TxnField(cx.program[cx.pc+2])
@@ -2260,7 +2263,10 @@ func opGtxnsas(cx *EvalContext) {
 
 	gtxid := int(cx.stack[prev].Uint)
 	if gtxid >= len(cx.TxnGroup) {
-		cx.err = fmt.Errorf("gtxnsa lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
+		cx.err = fmt.Errorf("gtxnsas lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
+		return
+	} else if gtxid < 0 {
+		cx.err = fmt.Errorf("gtxnsas lookup %d cannot be negative", gtxid)
 		return
 	}
 	tx := &cx.TxnGroup[gtxid].Txn
@@ -2272,7 +2278,7 @@ func opGtxnsas(cx *EvalContext) {
 	}
 	_, ok = txnaFieldSpecByField[field]
 	if !ok {
-		cx.err = fmt.Errorf("gtxnsa unsupported field %d", field)
+		cx.err = fmt.Errorf("gtxnsas unsupported field %d", field)
 		return
 	}
 	arrayFieldIdx := cx.stack[last].Uint
diff --git a/data/transactions/logic/eval_test.go b/data/transactions/logic/eval_test.go
index 2fcb2528f8..6ba30249af 100644
--- a/data/transactions/logic/eval_test.go
+++ b/data/transactions/logic/eval_test.go
@@ -1806,7 +1806,7 @@ int 2
 &&
 `
 
-	gtxnText := gtxnTextV4 + `int 0
+	gtxnTextV5 := gtxnTextV4 + `int 0
 gtxnas 0 Accounts
 gtxn 0 Sender
 ==
@@ -1823,7 +1823,7 @@ gtxn 0 Sender
 		1: gtxnTextV1,
 		2: gtxnTextV2,
 		4: gtxnTextV4,
-		5: gtxnText,
+		5: gtxnTextV5,
 	}
 
 	for v, source := range tests {

From d18878e6e0b089e7e07378dc077d7af10f59c0ec Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 14:21:24 -0400
Subject: [PATCH 5/7] Fix op docs

---
 data/transactions/logic/README.md       | 4 ++--
 data/transactions/logic/TEAL_opcodes.md | 4 ++--
 data/transactions/logic/doc.go          | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/data/transactions/logic/README.md b/data/transactions/logic/README.md
index cef3e87ed2..d7802ca479 100644
--- a/data/transactions/logic/README.md
+++ b/data/transactions/logic/README.md
@@ -243,8 +243,8 @@ Some of these have immediate data in the byte or bytes after the opcode.
 | `gloads i` | push Ith scratch space index of the Xth transaction in the current group |
 | `gaid t` | push the ID of the asset or application created in the Tth transaction of the current group |
 | `gaids` | push the ID of the asset or application created in the Xth transaction of the current group |
-| `txnas f` | pop an index A. push Ath value of the array field F of the current transaction |
-| `gtxnas t f` | pop an index A. push Ath value of the array field F from the Tth transaction in the current group |
+| `txnas f` | push Xth value of the array field F of the current transaction |
+| `gtxnas t f` | push Xth value of the array field F from the Tth transaction in the current group |
 | `gtxnsas f` | pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group |
 | `args` | push Xth LogicSig argument to stack |
 
diff --git a/data/transactions/logic/TEAL_opcodes.md b/data/transactions/logic/TEAL_opcodes.md
index 01f5909410..32747e61ef 100644
--- a/data/transactions/logic/TEAL_opcodes.md
+++ b/data/transactions/logic/TEAL_opcodes.md
@@ -1249,7 +1249,7 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 - Opcode: 0xc0 {uint8 transaction field index}
 - Pops: *... stack*, uint64
 - Pushes: any
-- pop an index A. push Ath value of the array field F of the current transaction
+- push Xth value of the array field F of the current transaction
 - LogicSigVersion >= 5
 
 ## gtxnas t f
@@ -1257,7 +1257,7 @@ bitlen interprets arrays as big-endian integers, unlike setbit/getbit
 - Opcode: 0xc1 {uint8 transaction group index} {uint8 transaction field index}
 - Pops: *... stack*, uint64
 - Pushes: any
-- pop an index A. push Ath value of the array field F from the Tth transaction in the current group
+- push Xth value of the array field F from the Tth transaction in the current group
 - LogicSigVersion >= 5
 
 ## gtxnsas f
diff --git a/data/transactions/logic/doc.go b/data/transactions/logic/doc.go
index 31dbd6a034..760c6a75c0 100644
--- a/data/transactions/logic/doc.go
+++ b/data/transactions/logic/doc.go
@@ -156,8 +156,8 @@ var opDocByName = map[string]string{
 	"tx_field":  "Set field F of the current application action",
 	"tx_submit": "Execute the current application action. Panic on any failure.",
 
-	"txnas":   "pop an index A. push Ath value of the array field F of the current transaction",
-	"gtxnas":  "pop an index A. push Ath value of the array field F from the Tth transaction in the current group",
+	"txnas":   "push Xth value of the array field F of the current transaction",
+	"gtxnas":  "push Xth value of the array field F from the Tth transaction in the current group",
 	"gtxnsas": "pop an index A and an index B. push Bth value of the array field F from the Ath transaction in the current group",
 	"args":    "push Xth LogicSig argument to stack",
 }

From 1bf8bfd07479d8e3f80cc35433ec811b82723002 Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 14:22:43 -0400
Subject: [PATCH 6/7] Fix cast

---
 data/transactions/logic/eval.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data/transactions/logic/eval.go b/data/transactions/logic/eval.go
index 4c88b83bf6..796b936068 100644
--- a/data/transactions/logic/eval.go
+++ b/data/transactions/logic/eval.go
@@ -2166,7 +2166,7 @@ func opGtxna(cx *EvalContext) {
 func opGtxnas(cx *EvalContext) {
 	last := len(cx.stack) - 1
 
-	gtxid := int(uint(cx.program[cx.pc+1]))
+	gtxid := int(cx.program[cx.pc+1])
 	if gtxid >= len(cx.TxnGroup) {
 		cx.err = fmt.Errorf("gtxnas lookup TxnGroup[%d] but it only has %d", gtxid, len(cx.TxnGroup))
 		return

From 12b0bb8a32b673e9f1887f815522e6d139735268 Mon Sep 17 00:00:00 2001
From: algochoi <86622919+algochoi@users.noreply.github.com>
Date: Tue, 7 Sep 2021 16:22:33 -0400
Subject: [PATCH 7/7] Fix gtxnsas opdoc

---
 cmd/opdoc/opdoc.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cmd/opdoc/opdoc.go b/cmd/opdoc/opdoc.go
index ad1ce4d2d9..2516e8ef1b 100644
--- a/cmd/opdoc/opdoc.go
+++ b/cmd/opdoc/opdoc.go
@@ -238,7 +238,7 @@ func argEnum(name string) []string {
 	if name == "global" {
 		return logic.GlobalFieldNames
 	}
-	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" {
+	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" || name == "gtxnsas" {
 		return logic.TxnaFieldNames
 	}
 	if name == "asset_holding_get" {
@@ -282,7 +282,7 @@ func argEnumTypes(name string) string {
 	if name == "global" {
 		return typeString(logic.GlobalFieldTypes)
 	}
-	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" {
+	if name == "txna" || name == "gtxna" || name == "gtxnsa" || name == "txnas" || name == "gtxnas" || name == "gtxnsas" {
 		return typeString(logic.TxnaFieldTypes)
 	}
 	if name == "asset_holding_get" {