Any mouse button triggers divider dragging

[jaymcp]

Expected Behaviour

Only the left mouse button should trigger the drag start on mousedown

Actual Behaviour

Depressing any mouse button triggers the drag start

Step-by-step reproduction instructions

1. insert an instance of this block, and add comparison images
2. view the frontend
3. try click-dragging the divider using the left mouse button
4. try click-dragging the divider using the right mouse button
5. try click-dragging the divider using the middle mouse button
6. repeat for any more mouse buttons you may happen to have

Screenshots, screen recordings, code snippets

Order of mouse buttons used in video (left, right, middle, mouse 5)

mouse-buttons.mp4

System Information

• Device: MacBook Pro
• Operating System: macOS Monterey v12.5
• Browser: Chrome 126.0.6478.127 arm64
• WordPress version: 6.4.4, 6.6-RC1-58586
• PHP version: 8.2