final line randomly deletes

[j-shen]

This bug has two main effects. 1. Frames toggled off for preview are toggled on (usually all, sometimes only a few). 2. Animation frames have the bottom row deleted, sometimes the next row if the bottom row has already been deleted. The behavior persisted even when I created a copy of the original file.

Steps to reproduce the bug

1. go to piskelapp.com
2. (I'm not sure what exactly causes the bug, it mostly seems to happen when I use ctrl+Z to undo things but it also happens at seemingly random times)
3. ...

Environment details

• operating system: Windows
• browser (or offline application version): Chrome

Sprite details

• number of frames: 13 (has been happening since around 8 or so)
• sprite resolution: 64x64
• session duration: has been happening intermittently over the last few days, ~ 5 hours' worth of use time

Feel free to include a screenshot of the bug, a .piskel file of the sprite or anything else that can help us investigate. (github doesn't seem to support .piskel files, at least through this window)

[PoolloverNathan]

same but for 40 frames of 24x24 only started happening after turning off a frame, now undoing deletes the last line and turns them all on New Piskel (12)-20210519-162855.zip