IsUndefined() breaks r_callback in v8 8.0.357

[JanMarvin]

Since v8 8.0.357 the args[x]->IsUndefined() condition does not work anymore. The R session crashes. If I keep only the Length() condition introduced in #71 all tests succeed.

diff --git a/src/bindings.cpp b/src/bindings.cpp
index 7f17653..f15487c 100644
--- a/src/bindings.cpp
+++ b/src/bindings.cpp
@@ -97,9 +97,9 @@ void r_callback(std::string fun, const v8::FunctionCallbackInfo<v8::Value>& args
     v8::String::Utf8Value arg0(args.GetIsolate(), args[0]);
     Rcpp::String fun(*arg0);
     Rcpp::CharacterVector out;
-    if(args.Length() == 1 || args[1]->IsUndefined()){
+    if(args.Length() == 1){
       out = r_call(fun);
-    } else if(args.Length() == 2 || args[2]->IsUndefined()) {
+    } else if(args.Length() == 2) {
       v8::Local<v8::Object> obj1 = v8::Local<v8::Object>::Cast(args[1]);
       v8::String::Utf8Value arg1(args.GetIsolate(), v8::JSON::Stringify(args.GetIsolate()->GetCurrentContext(), obj1).ToLocalChecked());
       Rcpp::String json(ToCString(arg1));

Not sure what changed this behavior, there have been a few commits in 8.0.357, but I have narrowed it down to this release.

[JanMarvin]

Thanks, wasn't sure if you wanted to keep the IsUndefined() behavior

[jeroen]

I don't remember why I used IsUndefined, it may be a legacy thing from V8 way back when.

I do find it strange how upstream keeps silently breaking the apis but your fix seems to work on all systems so 🤷‍♂ . Thanks!!