Wrap all exported functions to catch and unwind

All panics must be catch and unwind otherwise it is UB.
I recommend use catch_unwind with the following if let:

let result = panic::catch_unwind(|| {
    // ffi function call
});

if let Err(err) = result {
    // if `err` panic in `Drop` we will be sad
    forget(err);
}

You can create macro or function to resolve it
In currently implementation:

#[ffi::specialize_for(
    . . .
)]
unsafe fn drop_links<T: LinkType>(this: *mut c_void) {
    let links: &mut WrappedLinks<T> = unnull_or_panic(this);
    drop_in_place(links);
}

We can split to:

unsafe fn drop_links_impl<T: LinkType>(this: *mut c_void) {
    // impl
}

#[ffi::specialize_for(
    . . .
)]
unsafe fn drop_links<T: LinkType>(this: *mut c_void) {
    catch_unwind(/* some */)
}

Or add this behavior to ffi::specialize_for

Start by locating the exported FFI functions and the existing drop_links implementation that calls unnull_or_panic and drop_in_place. Compare wrapping each implementation with panic::catch_unwind against adding the behavior to ffi::specialize_for. Done means exported functions catch panics and safely discard panic payloads without changing their FFI behavior.