no typechecker error when missing overloaded refinements

The following code should not pass the typechecker but it does:

import java.lang { Appendable }

class X() satisfies Appendable {
    shared actual Appendable append(Character c) => this;
}

[quintesse]

With 1.2.2 I get:

./source/issue6433/run.ceylon:3: error: overloaded formal member 'append(CharSequence?)' of 'Appendable' not implemented in class hierarchy
class X() satisfies Appendable {
      ^
./source/issue6433/run.ceylon:3: error: overloaded formal member 'append(CharSequence?, Integer, Integer)' of 'Appendable' not implemented in class hierarchy
class X() satisfies Appendable {
      ^
2 errors

[FroMage]

Done.