EVABoundFix..ctor NullReferenceException loop on vessel switch

[edujoliver]

Summary

When FirstPersonEVA.Update() calls EVABoundFix.Hook(eva) after a vessel switch, the EVABoundFix constructor throws a NullReferenceException if any of the KFSM fields it touches are still null on that KerbalEVA instance. Because Update() re-attempts the hook every frame, the exception is logged 50+ times per second.

In long sessions this produces 200+ MB KSP.log files and contributes to Mono GC mark-stack overflow crashes.

Repro stack

NullReferenceException: Object reference not set to an instance of an object
    FirstPerson.EVABoundFix..ctor (KerbalEVA eva)
    FirstPerson.EVABoundFix.Hook (KerbalEVA eva)
    FirstPerson.FirstPersonEVA.Update ()

Source

EVABoundFix.cs lines 20–62:

EVABoundFix(KerbalEVA eva)
{
    myeva = eva;
    ReflectedMembers.Initialize();
    myeva.On_bound_fall.OnCheckCondition = ...; // NRE if On_bound_fall is null
    myeva.On_bound_land.OnCheckCondition = ...; // NRE if On_bound_land is null
    for (int i = 0; i < myeva.st_bound_fl.StateEvents.Count; ++i) // NRE if st_bound_fl null
    ...
}

Some custom EVA suits / mod-added KerbalEVAs initialize these fields lazily (or not at all), so the constructor hits a null reference. Since FirstPersonEVA.Update() doesn't track failed hooks, it tries again every frame.

Suggested fix

Either guard each access in the constructor, or have Hook validate the relevant fields before constructing:

public static void Hook(KerbalEVA eva)
{
    if (eva == null || eva.vessel == null) return;
    if (eva.On_bound_fall == null || eva.On_bound_land == null || eva.st_bound_fl == null) return;
    new EVABoundFix(eva);
}

It might also be worth tracking which KerbalEVA instances were successfully hooked so Update() doesn't retry them on every frame.

Workaround

Standalone Harmony Prefix that validates the fields before Hook runs and skips with deduplicated logging:

https://github.com/edujoliver/TTE-Fix

Happy to send a PR if useful.

Environment

• KSP 1.12.5
• Through-The-Eyes 2.0.4.5
• KSPCommunityFixes 1.39.1

[linuxgurugamer]

PR would be appreciated