editor: unexpected error while dragging end track range extremity

[jacomyal]

What happened?

When dragging both extremities of some speed section's track range to the start of the related track section, an error occurs.

What did you expect to happen?

Nor error should occur.

How can we reproduce it (as minimally and precisely as possible)?

1. Select a SpeedSection (preferably a one with few track ranges)
2. Click on "Edit selected item"
3. On any track range, select the end point, and move it until it reaches the start point

At this point, an error occurs with the message Uncaught Error: coordinates must be an array of two or more positions.

It is related to this issue:
Turfjs/turf#1577

What operating system, browser and environment are you using?

• Browser: Firefox and Chrome
• OS: Ubuntu
• Env: Local

OSRD version (top right corner Account button > Informations)

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