🐞 Cursor stutters at the top edge when Suppress Mission Control is on

[jvanderen1]

Bug Description

With Suppress Mission Control enabled, dragging a window into the top edge of the screen makes the cursor stutter. This is the same behavior as #609. That issue was closed by turning the toggle off, which avoids the stutter by letting Mission Control open. The stutter is still there on current develop if the toggle stays on.

Affected Scope

Performance

Steps to Reproduce

1. Enable window snapping and Suppress Mission Control.
2. Drag a window to the top edge of the screen and hold it there.

Reproducibility

Always

Expected vs Actual Behavior

Expected: The cursor stays smooth, Mission Control stays closed, and the top snap preview still works.

Actual: The cursor stutters while it is held on the top edge. Loop keeps Mission Control closed by calling CGWarpMouseCursorPosition on every drag event, which fights the upward drag.

Screen Recordings / Screenshots

Screencast is on the proposed fix: #1133

Severity

Major (workaround exists)

Workaround: turn Suppress Mission Control off. That is what #609 was closed with.

macOS Version

macOS 27.0

Loop Version

Current develop (df26d56). The warp is still in WindowDragManager.

Did You Try the Development Build?

Yes

Additional Context

Related: #609, fix in #1133.

I can keep that PR updated. Cursor was used to help draft this report; I reproduced the stutter and checked that current develop still warps the cursor.

Final Checks

• My issue is written in English.
• My issue title is descriptive.
• This is a single bug (multiple bugs should be reported individually).
• I have looked to see if this is a duplicate of another bug report.
• I can help with further investigation.
• I can help with developing a fix for this issue.