Open Radar

 
Summary:
When using Screen Sharing to remote control another Mac, dragging a file from one Finder window to another just bounces back. It only does it in certain cases but in those cases it is completely reproducible.

Attached is a video demonstrating the issue.

Steps to Reproduce:
1. Use screen sharing to control another Mac. In this case, both Macs are running High Sierra.
2. Have two Finder windows open on the remote-controlled Mac.
3. The windows should be partially overlapping.
4. The target window should be the Active window, the source window is partially behind it.
5. Drag a file from the source window to the target window, to move or copy the file (depending on which volume it is on).

Expected Results:
The file should move or copy the file.

Actual Results:
The Finder rejects the drag-and-drop operation, and the file bounces back to the source window.

Version/Build:
macOS High Sierra 10.13.6 (17G6030)

Configuration:
Mac being remote controlled is a MacBook Pro (15-inch, 2016)

Demonstration:
The attached demonstration video shows 5 attempts:
- Attempts 1, 2, 3 all fail
- Attempt 4 works.
- Attempt 5 has the source window in the foreground, which always works.

What's interesting is attempt 4. The only difference here is *where* I dragged the file to in the target window before dropping it.  Notice that it is further to the right side of the window.

This leads to a theory: when remote controlling, the Finder is acting as though the target of the move, in this situation, is the partially hidden source window -- it is rejecting the move because the place where I'm dropping the file is within the bounds of the SOURCE window, even though the Finder has clearly marked (via the blue rectangle) that the target window has been selected for the drop.

This same actions work fine if remote control isn't being used.