[0.17.62] Issue with Rail Signals

[Caaaaarrrrlll]

I will try my best to describe this issue in detail. On occasion, I've noticed when placing rail signals using personal construction robots, that the rail signal will flash green-yellow-red, instead of staying a steady color, for seemingly no reason.

The issue seems to happen when using copy-paste. If I place the rail signal by hand or if I shift+click for a robot to do it, the rail signal stays a steady color; it's only when copying and pasting that it flashes. It's also not reproducible in every segment of track.

I have been seeing this issue from time to time in my save, but I was unable to figure out how to reproduce it until now. I saw this issue with previous patches, but I'm not sure how far back, it was between 2 to 10 patches ago. I can't help but be curious if it had something to do with reworking the rails from FFF-299.

I've attached a video preview below (from my Google Drive) and attached to this thread a zip file that contains both the video and the save file, for further analysis and debugging.

Video: https://drive.google.com/open?id=1hI9A1 ... tiL3NRfL9q

[Merssedes]

For me it looks like copy-past saves signals orientation (there is 8 of them in total) and therefore does not attach to rail. Notice how 2nd signal (right one) don't want to be placed (red).
Try to rotate copy twice before pasting. Is it still flashing?

[Caaaaarrrrlll]

For me it looks like copy-past saves signals orientation (there is 8 of them in total) and therefore does not attach to rail. Notice how 2nd signal (right one) don't want to be placed (red).
Try to rotate copy twice before pasting. Is it still flashing?

Hmmm. That worked. Would this be intended functionality, then?

I would have figured the side of the rail that it's placed on would be higher precedence, unless there was an adjacent rail on either side of the signal.