avm1: Fix regression with action_get_url_2 and MovieClip without DisplayObject

[evilpie]

Fixes #22674

This was a regression introduced in #22221.

Before:

ruffle/core/src/avm1/activation.rs

Lines 1256 to 1261 in 9b3d688

	if let Value::Object(target) = target_val {
	target.as_display_object()
	} else if let Value::MovieClip(_) = target_val {
	let tgt = target_val.coerce_to_object(self);
	tgt.as_display_object()
	} else {

After:

ruffle/core/src/avm1/activation.rs

Lines 1217 to 1219 in c6e0cb0

	if let Some(target) = target_val.as_object(self) {
	target.as_display_object()
	} else {

The code is subtly different. Before, we used None if the MovieClip didn't have a DisplayObject, but afterwards, we fell through to the else block.

/cc @moulins

[kjarosh]

Having a test would be nice. Otherwise we'll regress it again in the future.

[kjarosh]

Also, see https://discord.com/channels/610531541889581066/1018988628380241931/1457721092184735917 for discussion about this.

[evilpie]

While the new behavior did cause the game to break, the new behavior might actual match Flash?

class Test {
    static function main() {
        var mc = _root.createEmptyMovieClip("mc", 1);
        mc.removeMovieClip();
        // This should NOT unload _root.
        loadMovie("", mc);

        // Check after a delay that _root was not unloaded.
        _root.checkId = setInterval(function() {
            clearInterval(_root.checkId);
            trace("_totalframes: " + _root._totalframes);
        }, 200);
    }
}

This logs nothing for me in Flash.