Open Radar

 
Area:
Something not on this list

Summary:
When transitioning an NSCursor (e.g. between `arrow` and `pointingHand`), the cursor often jumps a small amount for a frame or two before jumping back to what seems like the proper position.

Steps to Reproduce:
1. Find somewhere in an app that uses the `pointingHand` cursor, such as the attached HTML file in Safari.
2. Move the mouse between the two halves of the HTML document to toggle between `arrow` and `pointingHand`.

Expected Results:
The `arrow` cursor transitions into the `pointingHand` cursor and back in a smooth fashion with no jumpiness.

Actual Results:
The cursor often (maybe 50% of the time?) jumps (by maybe 10-15 points if I had to guess) very briefly (maybe for a frame or two?) before snapping back to the expected positioning.

Possibly interesting notes:
If you open QuickTime Player and make a screen recording, you can't see the cursor jump. But if you watch with your own eyes, or record the screen with your iPhone (use slo-mo), you can see the cursor jump.

You can see the same issue in Preview. Open a wide or tall document, then hold Option-Space to switch to the open-hand cursor, and release to go to crosshair. Repeat a few times and you'll see the jump.

Once you see it, you can't un-see it. Sorry.

Baseless conjecture:
It might happen more between cursors that have different hot spots?

Version/Build:
macOS 10.14.2 (18C54)

Configuration:
iMac (Retina 5K, 27-inch, Late 2014)