mfb opened the ticket and wrote:

At openttdcoop we found two setups where train can make 90°-turns even if they are not allowed to. Both are 100% reproducible in specific setups.
See the attached savegame, both locations are marked with a sign "!90degree turn bug".
The upper one appears always when a train enters that track.
To see the lower one, release train 588 (currently blocking the line). To get the bug, it is important that red twoway signals are considered as end of line. In addition, the twoway signal has to be red when the second train enters, and get green before it finishes the first round in the circle.

Observed and tested with r24673 and seen in r22255.

All NewGRFs in the savegame which are not available ingame can be found in the openttdcoop GRF package: http://wiki.openttdcoop.org/GRF
I don't think they influence the bug.

Attachments

• 90deg-turn-bugs.sav (735.21 KiB)

Reported version: trunk
Operating system: All

This issue was imported from FlySpray: https://bugs.openttd.org/task/5370