Sometimes undo slider changes set the anchor type to bezier

[cihe13375]

Type

Game behaviour

Bug description

1. create a straight slider
2. change the first anchor type to perfect curve
3. add an anchor in the middle
4. drag the new anchor
5. ctrl+z twice
6. note that the first anchor type becomes bezier.

Also it can be seen that the slider is somehow extended when changing the anchor type in step (2), though idk if that's a bug.

Screenshots or videos

aaaa.mp4

Version

2024.625.2 (the video is recorded on a custom build but I can confirm the issue also exists on 2024.625.2 official release)

Logs

[bdach]

This is happening because the following part of beatmap decoder is running interference:

osu/osu.Game/Rulesets/Objects/Legacy/ConvertHitObjectParser.cs

Lines 346 to 358 in 5633297

	// Edge-case rules (to match stable).
	if (type == PathType.PERFECT_CURVE)
	{
	int endPointLength = endPoint == null ? 0 : 1;
	if (vertices.Length + endPointLength != 3)
	type = PathType.BEZIER;
	else if (isLinear(points[0], points[1], endPoint ?? points[2]))
	{
	// osu-stable special-cased colinear perfect curves to a linear path
	type = PathType.LINEAR;
	}
	}

I'm not sure what the solution is here. A better serialisation format with no silent coercions of this sort, perhaps. Or a better editor change tracking system that does not rely on encoding/decoding the beatmap. Neither is probably happening in the nearest months.

@smoogipoo any better ideas?

[smoogipoo]

Other than perhaps using the beatmap version if that's even available, I don't have any better ideas right now.