A DESCRIPTION OF THE PROBLEM :
In package a, there's a Outer with a _private_ class inner Inner, which in turn contains a _public_ inner class Supplier. Outer has a method with a parameter of type Supplier. In package b, I invoke that method with a Lambda expression.

I'd expect compilation to fail as the Lambda implements a type which isn't accessible from package b, but compilation succeeds.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
mkdir -p compiler-bug/src/a compiler-bug/src/b compiler-bug/classes
cd compiler-bug

cat > src/a/Outer.java <<EOF
package a;

public class Outer {

  private static class Inner {

    @FunctionalInterface
    public interface Supplier {
      int getInt();
    }
  }

  public static void invoke(Inner.Supplier supplier) {}
}
EOF

cat > src/b/Reference.java <<EOF
package b;

import a.Outer;

public class Reference {

  public static void main(String[] args) {
    Outer.invoke(() -> 42);
  }
}
EOF

javac src/a/Outer.java src/b/Reference.java -d classes

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Compilation fails. E.g. the Eclipse compiler ecj reports:

"The type Outer.Inner from the descriptor computed for the target context is not visible here."
ACTUAL -
Compilation succeeds.

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See "Steps to Reproduce".
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