FULL PRODUCT VERSION :
java version "9"
Java(TM) SE Runtime Environment (build 9+181)
Java HotSpot(TM) 64-Bit Server VM (build 9+181, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux mathisubuntu 4.10.0-35-generic #39~16.04.1-Ubuntu SMP Wed Sep 13 09:02:42 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
In jshell (works fine in normal java code)
a
  class A<T>
has a method of return type Supplier<T> and any nested class (required!). It returns an instance of a
  class B<T> implements Supplier<T>
using the constructor
  public B(A<T> a) [...]
thus inferring the type.
When attempting to instanciate A (attempting to load it), it says "A<T> cannot be converted to A<T>"

(PS: there is no specific bug report option for jshell, so I assumed "multiple applications" reports would be redirected anyways)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) Take the code included in this report. Copy it into a file
2) open it in jshell using /open [filename] or jshell [filename]
3) try to do new A()

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
a new instance of A is created without error, as it happens when run via normal javac + java.

ACTUAL -
When, and >only< when A has a nested class (here SomeClass) the following error occurs:
| Error:
| cannot infer type arguments for B<>
| reason: cannot infer type-variable(s) T
| (argument mismatch; A<T> cannot be converted to A<T>)
| return new B<>(this);
| ^-----------^

ERROR MESSAGES/STACK TRACES THAT OCCUR :
| Error:
| cannot infer type arguments for B<>
| reason: cannot infer type-variable(s) T
| (argument mismatch; A<T> cannot be converted to A<T>)
| return new B<>(this);
| ^-----------^

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.function.Supplier;

public class A <T> {
  private class SomeClass { //error only occurs when this is present

  }
  public Supplier<T> m1() {
    return new B<>(this);
  }
}

public class B <T> implements Supplier<T> {
  public B(A<T> a) {

  }

  private class D {} //does not influence result

  public T get() {return null;}
}
---------- END SOURCE ----------