[0.17.47] Crash when placing rail under moving train

[meznak]

When trying to modify a live rail system, I placed a curved piece of track just as a train was passing over where the segment started. The game immediately paused as though it was autosaving, but without the popup. I then got the crash dialog.

I have not been able to repro the crash.

Unsure if it's relevant, but the train was rocket fueled and moving at what appeared to be full speed.

[boskid]

Duplicate 71717 (fixed and pending for release)