Railway & bridge-related freezes

[instafluff0]

A user mentions:

So how it works in my case:

1. When any worker needs to move into water tiles near city by manually moving him with my cursor - everything is ok.
2. When any worker manually added to transort ship and moved into water to made a bridge - everything is ok.
3. When any worker moved to bridge-completed water tile and commanded to build railroad on it - everyrhing is ok.
   But
4. When I chose to build a railroad from one bank or coast to another through bridge - it just freezes (do not see a path?). If I manually move a worker through bridge to the first tile on another bank, and start build road here - everything is ok.
5. When I manually place tile by tile railroads on a bridge - everything is ok (until this bridge in neutral terrirtory - then railroaded medieval bridge just disappeared but still works as a bridge with railroad). When I build a city near and cover that neutral terrirtory to my borders, then invisible bridge show up again.
6. When there is no other land connected to that other island connected only by bridge, workers do not try to auto-move across the bridge. But if travelled manually then commanded to be auto - they work just fine but cannot leave island.
7. When any worker tries to auto-work on coastal tiles (if it is checked in c3x config as avaiable) - game freezes. So I unchecked it.
8. When any worker tries to auto work in another part of land (it has a shape of large "C" letter and it's points connected with bridge, so there is a shortcut with bridge and a large detour on land) - it tries to move shortest way by bridge and freezes a game.
   Something about pathfinding I think. Or something messing around in my modded files from 2012 :lol:_

I've created a scenario and attempted to reproduce these bugs, but have not been able to yet. As far as I know this has not been reported by anyone else. When I asked the user for a save they said: "Sadly, it would be not possible as it in my custom scenario, with over 8000k units in folder, and over 1000k saved units on map." Not sure that is related to the issue.