Current Behavior

Middle mouse button panning works when clicking and dragging on empty workspace background.

However, middle-click panning does not work when the cursor is positioned over:

• A link (wire)
• A node port hitbox

In those cases, the workspace does not enter panning mode.

• For line it does not do anything just selects the line.
• For node port hitbox, it acts as left-click.

Expected Behavior

Middle-click panning should work consistently across the entire workspace surface, including when the cursor is positioned over links and ports.

Steps To Reproduce

Open Node-RED editor

• Create two nodes and connect them with a wire
• Middle-click and drag on empty workspace → pan works
• Middle-click and drag while cursor is positioned over:
  • The wire
  • A node port

Observed result: panning does not activate.

Example flow

Environment

• Node-RED version: 4.1.5
• Node.js version: v20.20.0
• npm version: 10.8.2
• Platform/OS: Ubuntu 24.04.4 LTS (Linux 6.17.0-14-generic x86_64)
• Browser: Google Chrome 145.0.7632.109 (64-bit)

A potential fix would be to ignore non-left mouse buttons in linkMouseDown and portMouseDown before calling stopPropagation(). I have tried this fix and it worked as expected. If the current behavior is not an expected behavior, i can raise a PR for this.