michi_cc opened the ticket and wrote:

FollowTrackRail() and its siblings from yapf.h are currently not usable, depending on compiler version, moon phase or whatever. This is currently not a problem as trunk doesn't use this functions at the moment.

The problem is that the user of these functions has to provide a FollowTrack_t structure, which is then cast to a CFollowTrackT structure derived from FollowTrack_t. But CFollowTrackT has one additional member over FollowTrack_t, so depending on how the compiler generates code, an access to that member can overwrite memory. (Seen with MSVC2005 using debug runtime with full stack checking.)

I've extracted this solution to the problem from YAPP. It is more radical than just moving the offending member to the base structure, but this way is more elegant code-wise as it removes the need to use different functions for each transport type and for with or without 90 degree turns. Using CFollowTrackT directly would still have the problem that at least an if statement for 90 degree turns is neccessary.

Attachments

• fix_follow_track_t.patch (4.19 KiB)

Reported version: trunk
Operating system: All

This issue was imported from FlySpray: https://bugs.openttd.org/task/1801