Consider this code, with a code completion invocation:

package test;

public class Test {
    private void test(Runnable r) {
        test(() -> {
            new Base<Void, Void>() {
                //code completion here
            };
        });
    }
}

class Base<T1, T2> {
    public T1 test(T1 p) {}
}

invoke the code completion at the marked place, and select the "test(Void p) - override" option. Nothing will happen, nothing will added to the source code.

The reason is this:

• there is an (API) Scope taken at the place of the cursor. The Scope's Env<AttrContext> has a returnResult filled, and this returnResult has a checkContext that throws exceptions. This is part of method overload resolution in javac.
• the code completion will delegate to GeneratorUtilities.createOverridingMethod, attempting to create the method.
• createOverridingMethod will try to parse&attribute code like:

{
    return super.test(p);
}

in the context of the above Scope. But the return statement here does not match the expected return type from the Scope, and so it will go to the checkContext, and fail with the exception.

This is a bit tricky, as a) the Scope here is used in a bit unintended way; b) many of the fields and types responsible for this are package private.

The proposal in this PR is to replace the checkContext in the returnResult with the default value (Check.basicHandler). That should, hopefully, solve this and any other similar problems.