proto/msgpack: Allow nil=false simplification

NEO/py sometimes sends 'None' for boolean values (being equal to 'False'
due to pythons 'bool(None) == False' logic). Let's accept python based
False values (= Nil) as equally acceptable.

Without this patch we can see errors as:

xtesting.go:330: load 0285cbad6e147b66:0000000000000005: returned err unexpected:
        have: neo://127.0.0.1:30002/1: load 0285cbad6e147b66:0000000000000005: 127.0.0.1:48928 - 127.0.0.1:33051 .251: decode: decode: M: AnswerObject.Compression/op: got opcode 00;  expected any from c3c2

go/neo/proto/protogen.go

@@ -1175,6 +1175,21 @@ func (d *decoderM) genBasic(assignto string, typ *types.Basic, userType types.Ty
 		d.emit("}")
 	}
 
+	// mgetbool emits bool
+	mgetbool := func(optional bool) {
+		d.emit("switch op := msgpack.Op(data[%v]); op {", d.n)
+		d.emit("default: return 0, mdecodeOpErr(%q, op, msgpack.True, msgpack.False)", d.pathName(assignto))
+		d.emit("case msgpack.True:  %s = true", assignto)
+		d.emit("case msgpack.False: %s = false", assignto)
+		if optional {
+			d.emit("case msgpack.Nil : %s = false", assignto)
+		}
+		d.emit("}")
+
+		d.n++
+		d.overflow.Add(1)
+	}
+
 	// IdTime can be nil ('None' in py), in this case we use
 	// infinite -1, see
 	// https://lab.nexedi.com/kirr/neo/-/blob/1ad088c8/go/neo/proto/proto.go#L352-357
@@ -1184,15 +1199,7 @@ func (d *decoderM) genBasic(assignto string, typ *types.Basic, userType types.Ty
 	}
 
 	switch typ.Kind() {
-	case types.Bool:
-		d.emit("switch op := msgpack.Op(data[%v]); op {", d.n)
-		d.emit("default: return 0, mdecodeOpErr(%q, op, msgpack.True, msgpack.False)", d.pathName(assignto))
-		d.emit("case msgpack.True:  %s = true", assignto)
-		d.emit("case msgpack.False: %s = false", assignto)
-		d.emit("}")
-
-		d.n++
-		d.overflow.Add(1)
+	case types.Bool:        mgetbool(true)
 
 	case types.Int8:	mgetint("", 8)
 	case types.Int16:	mgetint("", 16)

go/neo/proto/zproto-marshal.go

@@ -2422,6 +2422,8 @@ func (p *StartOperation) neoMsgDecodeM(data []byte) (int, error) {
 		p.Backup = true
 	case msgpack.False:
 		p.Backup = false
+	case msgpack.Nil:
+		p.Backup = false
 	}
 	return 2, nil
 
@@ -4914,6 +4916,8 @@ func (p *AnswerRebaseObject) neoMsgDecodeM(data []byte) (int, error) {
 		p.Compression = true
 	case msgpack.False:
 		p.Compression = false
+	case msgpack.Nil:
+		p.Compression = false
 	}
 	if op := msgpack.Op(data[21]); op != msgpack.Bin8 {
 		return 0, mdecodeOpErr("AnswerRebaseObject.Checksum", op, msgpack.Bin8)
@@ -5105,6 +5109,8 @@ func (p *StoreObject) neoMsgDecodeM(data []byte) (int, error) {
 		p.Compression = true
 	case msgpack.False:
 		p.Compression = false
+	case msgpack.Nil:
+		p.Compression = false
 	}
 	if op := msgpack.Op(data[21]); op != msgpack.Bin8 {
 		return 0, mdecodeOpErr("StoreObject.Checksum", op, msgpack.Bin8)
@@ -6062,6 +6068,8 @@ func (p *AnswerObject) neoMsgDecodeM(data []byte) (int, error) {
 		p.Compression = true
 	case msgpack.False:
 		p.Compression = false
+	case msgpack.Nil:
+		p.Compression = false
 	}
 	if op := msgpack.Op(data[31]); op != msgpack.Bin8 {
 		return 0, mdecodeOpErr("AnswerObject.Checksum", op, msgpack.Bin8)
@@ -6612,6 +6620,8 @@ func (p *AnswerTransactionInformation) neoMsgDecodeM(data []byte) (int, error) {
 		p.Packed = true
 	case msgpack.False:
 		p.Packed = false
+	case msgpack.Nil:
+		p.Packed = false
 	}
 	{
 		data = data[1:]
@@ -7916,6 +7926,8 @@ func (p *TweakPartitionTable) neoMsgDecodeM(data []byte) (int, error) {
 		p.DryRun = true
 	case msgpack.False:
 		p.DryRun = false
+	case msgpack.Nil:
+		p.DryRun = false
 	}
 	{
 		data = data[1:]
@@ -8091,6 +8103,8 @@ func (p *AnswerTweakPartitionTable) neoMsgDecodeM(data []byte) (int, error) {
 		p.Changed = true
 	case msgpack.False:
 		p.Changed = false
+	case msgpack.Nil:
+		p.Changed = false
 	}
 	{
 		data = data[1:]
@@ -8442,6 +8456,8 @@ func (p *Repair) neoMsgDecodeM(data []byte) (int, error) {
 		p.repairFlags.DryRun = true
 	case msgpack.False:
 		p.repairFlags.DryRun = false
+	case msgpack.Nil:
+		p.repairFlags.DryRun = false
 	}
 	return 3 + int(nread), nil
 
@@ -8515,6 +8531,8 @@ func (p *RepairOne) neoMsgDecodeM(data []byte) (int, error) {
 		p.repairFlags.DryRun = true
 	case msgpack.False:
 		p.repairFlags.DryRun = false
+	case msgpack.Nil:
+		p.repairFlags.DryRun = false
 	}
 	return 3, nil
 
@@ -9097,6 +9115,8 @@ func (p *AnswerObjectUndoSerial) neoMsgDecodeM(data []byte) (int, error) {
 				mv.IsCurrent = true
 			case msgpack.False:
 				mv.IsCurrent = false
+			case msgpack.Nil:
+				mv.IsCurrent = false
 			}
 			m[key] = mv
 			data = data[21:]
@@ -9486,6 +9506,8 @@ func (p *AnswerPack) neoMsgDecodeM(data []byte) (int, error) {
 		p.Status = true
 	case msgpack.False:
 		p.Status = false
+	case msgpack.Nil:
+		p.Status = false
 	}
 	return 2, nil
 
@@ -12543,6 +12565,8 @@ func (p *AddTransaction) neoMsgDecodeM(data []byte) (int, error) {
 		p.Packed = true
 	case msgpack.False:
 		p.Packed = false
+	case msgpack.Nil:
+		p.Packed = false
 	}
 	if op := msgpack.Op(data[1]); op != msgpack.Bin8 {
 		return 0, mdecodeOpErr("AddTransaction.TTid", op, msgpack.Bin8)
@@ -12732,6 +12756,8 @@ func (p *AddObject) neoMsgDecodeM(data []byte) (int, error) {
 		p.Compression = true
 	case msgpack.False:
 		p.Compression = false
+	case msgpack.Nil:
+		p.Compression = false
 	}
 	if op := msgpack.Op(data[21]); op != msgpack.Bin8 {
 		return 0, mdecodeOpErr("AddObject.Checksum", op, msgpack.Bin8)