This is likely going to end up interned lateron at some point
when the new_name is referenced somewhere. However, it may be
that there are some uses that do not get interned before that.
In this case we will intern a string that already have zval
users, without updating the refcounted flag on those zvals.
In particular this can happen with something like [Foo::class],
where Foo is an imported symbol. The string it resolves to won't
get interned right away, but may be interned later.
use Foo as Bar;
$x = [Bar::class];
var_dump(Bar::X);
debug_zval_dump($x); // Will show negative refcount
class Foo {
const X = 1;
}
However, this doesn't really fix the root cause, there are probably
other situations where something similar can occur.