Crash releasing mouse after Shift-scaling with 'quick' selection

[Gasparoken]

Describe the bug
A 100% reproducible crash occurs when scaling a selection + SHIFT pressed while using a Selection Tool configured as a Quick Tool.
Internal report: https://igarastudio.zendesk.com/agent/tickets/9393

To Reproduce

1. Configure a selection tool (for example Rectangular Marquee Tool) as a Quick Tool instead of using the default configuration.

2. Select the Pencil Tool as the active tool.
3. Draw at least one pixel on the canvas.
4. Create a selection using the Quick Tool by holding M, then clicking and dragging the mouse.
5. Once the selection is created, continue holding M to display the selection handles.

6. While still holding M, press and hold Shift, then click and drag one of the selection handles. The selection will not be scaled.
7. Keeping Shift pressed, release the left mouse button --> crash.

Aseprite & System:

• Aseprite: 1.3.17.2
• System: macOS and Windows

[bayl0n]

Adding to this, this can also be reproduced when clicking the handle whilst holding M and then pressing Shift afterwards too