Interactiion between NotOnlyInitialized and UnderInitialization

[jpschewe]

There appears to be an odd interaction between NotOnlyInitialized and UnderInitialization.
Reading https://checkerframework.org/manual/#fig-initialization-hierarchy and the sections after it, I understand that an object is considered UnderInitialization for itself when all of the non-null fields have been assigned.
I have a class that has a NotOnlyInitialized field and a NonNull field. Once both fields are initialized I call a private method on the class. At this point I expect the state of this to be UnderInitialization(current class), however it's UnderInitialization(parent class).

Steps to reproduce:

1. git clone https://github.com/jpschewe/checker-bugs.git
2. cd checker-bugs
3. git checkout notonlyinitialized-underinitialization
4. ./gradlew clean; ./gradlew classes

Resulting error

/home/jpschewe/projects/checker-bugs/src/main/java/net/mtu/eggplant/checker/issue4613/SchedulerUI.java:25: error: [method.invocation] call to createMenubar() not allowed on the given receiver.
    createMenubar();
                 ^
  found   : @UnderInitialization(javax.swing.JFrame.class) @NonNull SchedulerUI
  required: @UnderInitialization(net.mtu.eggplant.checker.issue4613.SchedulerUI.class) @NonNull SchedulerUI
1 error

[vatsalllll]

FIX 1: Use @initialized on private method call (trusts initialization complete):
@initialized
private void createMenubar() { ... }

FIX 2: Explicit cast after field init (suppresses receiver check):
createMenubar((@initialized SchedulerUI) this);

FIX 3: @SuppressWarnings on call site (with proof comment):
@SuppressWarnings("initialization") // Both notOnlyField & nonNullField initialized above
createMenubar();

FIX 4: Initialize NotOnlyInitialized field earlier, before NonNull field:
this.notOnlyField = initializeNotOnlyField(); // FIRST
this.nonNullField = new NonNullType(); // THEN private method call

Why? NotOnlyInitialized has custom init semantics; checker conservatively uses
parent class state until ALL fields (incl. custom ones) provably initialized.
See Initialization Checker manual Fig 3.5 & custom qualifier docs.