fix: to avoid panic on untyped nil #290

fix #290

encode_test.go

@@ -2148,3 +2148,23 @@ func TestEmptyStructInterface(t *testing.T) {
 		t.Fatalf("failed to encode empty struct interface. expected:[%q] but got:[%q]", expected, got)
 	}
 }
+
+func TestIssue290(t *testing.T) {
+	type Issue290 interface {
+		A()
+	}
+	var a struct {
+		A Issue290
+	}
+	expected, err := stdjson.Marshal(a)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := json.Marshal(a)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(expected, got) {
+		t.Fatalf("failed to encode non empty interface. expected = %q but got %q", expected, got)
+	}
+}

internal/cmd/generator/vm.go.tmpl

@@ -194,7 +194,9 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			if code.Flags&encoder.NonEmptyInterfaceFlags != 0 {
 				iface := (*nonEmptyInterface)(up)
 				ifacePtr = iface.ptr
+				if iface.itab != nil {
 				    typ = iface.itab.typ
+				}
 			} else {
 				iface := (*emptyInterface)(up)
 				ifacePtr = iface.ptr

internal/encoder/vm/vm.go

@@ -194,7 +194,9 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			if code.Flags&encoder.NonEmptyInterfaceFlags != 0 {
 				iface := (*nonEmptyInterface)(up)
 				ifacePtr = iface.ptr
+				if iface.itab != nil {
 					typ = iface.itab.typ
+				}
 			} else {
 				iface := (*emptyInterface)(up)
 				ifacePtr = iface.ptr

internal/encoder/vm_color/vm.go

@@ -194,7 +194,9 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			if code.Flags&encoder.NonEmptyInterfaceFlags != 0 {
 				iface := (*nonEmptyInterface)(up)
 				ifacePtr = iface.ptr
+				if iface.itab != nil {
 					typ = iface.itab.typ
+				}
 			} else {
 				iface := (*emptyInterface)(up)
 				ifacePtr = iface.ptr

internal/encoder/vm_color_indent/vm.go

@@ -194,7 +194,9 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			if code.Flags&encoder.NonEmptyInterfaceFlags != 0 {
 				iface := (*nonEmptyInterface)(up)
 				ifacePtr = iface.ptr
+				if iface.itab != nil {
 					typ = iface.itab.typ
+				}
 			} else {
 				iface := (*emptyInterface)(up)
 				ifacePtr = iface.ptr

internal/encoder/vm_indent/vm.go

@@ -194,7 +194,9 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			if code.Flags&encoder.NonEmptyInterfaceFlags != 0 {
 				iface := (*nonEmptyInterface)(up)
 				ifacePtr = iface.ptr
+				if iface.itab != nil {
 					typ = iface.itab.typ
+				}
 			} else {
 				iface := (*emptyInterface)(up)
 				ifacePtr = iface.ptr