[BUG] Segfaults resulting from unowned degraded ways

[freddyhayward]

A series of segfaults result from certain interactions with unowned, degraded ways.
The following will only crash the client:
* Trying to place ways in place of or connecting to the degraded way, either of the same type or of some incompatible ways (e.g. rail and narrow gauge) (road and waterways, road and rail, do not crash)
* Trying to place ways of the same type (e.g. rail and rail, road and road) within three tiles of the degraded way

The following will crash both the client and the server:
* Placing a bridge to the degraded way with one end falling within 5 tiles of the degraded way (this showed an error message on one occasion, see attached .png)

The following will not crash at all, some of which are demonstrated in the savegame:
* Removing degraded ways
* Placing stops, signals or electrification on degraded ways
* Creating road-rail crossings using degraded ways
* Placing ways of the same type, including bridges, within three (or five in the case of bridges) tiles of the degraded way when there is no direct path to it (see savegame)
* Placing ways of the same type within three (or five) tiles of the degraded way at different heights
* Placing elevated ways of the same type within three tiles of the degraded way, even if at the same height

EDIT: None of these crashes occur on simutrans-extended f3b6d42, tested on both an older and the most recent version of pak128.britain-ex

[jamespetts]

Thank you for your report: I believe that this was caused by a single bug that caused two other reported crashes and which I have now fixed, as I can not reproduce this with the fixed version.

I should be grateful if you could confirm that this has been fixed with to-morrow's nightly build.

[freddyhayward]

Thanks, the latest build has fixed the issue.