Sprite Editor: GM unstable when moving multiple frames at once in the preview bar

[KormexGit]

Description

Selecting and moving multiple frames in a sprite at once causes a "GameMaker has become unstable" popup, and also creates weird non-existent frames in the middle of the sprite.

[16:41:35:129(fb79)] Fatal Error! 'UndoManager::DoUndoableAction - Object reference not set to an instance of an object.'
[16:41:35:131(fb79)]    at YoYoStudio.Plugins.SpriteEditor.SpriteEditorModule.<>c__DisplayClass88_0.<DopeSheet_KeyMoved>b__0()
   at YoYoStudio.Core.Utils.UndoManager.DoUndoableAction(String _description, Object _objectsToTrack, Action _actionDelegate, Object _contextOverride)

GameMaker-Beta_oQbe80wgNI.mp4

Steps To Reproduce

1. Start GM and create a blank new project
2. Create a new sprite
3. In the Sprite Editor, right-click in the dopesheet to add more frames/use the hotkey for this until you have 10 frames in the sprite (you can perform this step in the Image Editor also, if you wish)
4. Click frame 1, press-and-hold shift, then click frame 4 in order to multi-select all 4 frames
5. Drag them past frame 10 of the animation and observe the frame count keeps going up, but that it's non-existent frames that are being added
6. Release the mouse button when your selected frames are at the end of the sprite and you have created some of these duff frames mentioned in step 5
7. Observe the unstable dialog appears

Which version of GameMaker are you reporting this issue for?

IDE v2024.800.0.597 Runtime v2024.800.0.620

Which operating system(s) are you seeing the problem on?

Windows 10.0.22631.0

fc0f5c3c-d48c-4c93-b076-5f1fc913779f

[yyalansavage]

fix applied in August and LTS branches

[YYDan]

Works fine in IDE v2024.800.0.611 Runtime v2024.800.0.635 now - you're no longer able to drag the frames out to create the extra gaps (and also the selection boxes are much more reliable now, as in that earlier version it looked like your selection was changed as you dragged). I have not been able to recreate the instability either.

[alicemoretti]

Verified picked to LTS on both Windows and mac on IDE v2022.0.3.74 Runtime v2022.0.3.85