STR:
$ cat -n Foo.java
     1 public class Foo {
     2 public static void main(String[] args) {
     3 var x = add(2, 3);
     4 var y = 37;
     5 var z = 42;
     6 }
     7
     8 private static int add(int x, int y) {
     9 return x + y;
    10 }
    11 }
    12

Perform the following jdb commands:

    stop at Foo:9
    run Foo

    trace method exit
    cont

    untrace
    next

It's expected to stop at the start of `add`, then continue until its end and then step over back to line 3 in `main`.

That's how it works with OpenJDK 23:

    $ jdb Foo
    Initializing jdb ...
    > stop at Foo:9
    Deferring breakpoint Foo:9.
    It will be set after the class is loaded.
    > run Foo
    run Foo
    Set uncaught java.lang.Throwable
    Set deferred uncaught java.lang.Throwable
    >
    VM Started: Set deferred breakpoint Foo:9

    Breakpoint hit: "thread=main", Foo.add(), line=9 bci=0
    9 return x + y;

    main[1] trace method exit
    main[1] cont
    >
    Method exited: return value = 5, "thread=main", Foo.add(), line=9 bci=3
    9 return x + y;

    main[1] untrace
    main[1] next
    >
    Step completed: "thread=main", Foo.main(), line=3 bci=5
    3 var x = add(2, 3);

OpenJDK 24 & 25 don't stop after `next` instruction.

    $ jdb Foo
    Initializing jdb ...
    > stop at Foo:9
    Deferring breakpoint Foo:9.
    It will be set after the class is loaded.
    > run Foo
    run Foo
    Set uncaught java.lang.Throwable
    Set deferred uncaught java.lang.Throwable
    >
    VM Started: Set deferred breakpoint Foo:9

    Breakpoint hit: "thread=main", Foo.add(), line=9 bci=0
    9 return x + y;

    main[1] trace method exit
    main[1] cont
    >
    Method exited: return value = 5, "thread=main", Foo.add(), line=9 bci=3
    9 return x + y;

    main[1] untrace
    main[1] next
    >
    The application exited