TTE Fix

Small Harmony patch that silences a recurring NullReferenceException loop in the Through-The-Eyes mod (a.k.a. ThroughTheEyes / FirstPerson).

The bug

FirstPerson.FirstPersonEVA.Update() runs every frame. Whenever the active vessel changes, it calls EVABoundFix.Hook(eva), which constructs a new EVABoundFix(eva) instance. The constructor touches several KFSM fields directly:

myeva.On_bound_fall.OnCheckCondition  = ...
myeva.On_bound_land.OnCheckCondition  = ...
for (int i = 0; i < myeva.st_bound_fl.StateEvents.Count; ++i) ...

For some custom EVA suits or specific game states one of these fields is still null, so the constructor throws a NullReferenceException. Because Update() keeps calling Hook on every frame, the exception is logged hundreds of times per second. In long sessions this floods KSP.log (seen growing to 200+ MB) and contributes to Mono GC mark-stack overflow crashes.

Sample stack from KSP.log:

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

The fix

A Harmony Prefix on FirstPerson.EVABoundFix.Hook reflects into the KerbalEVA and checks the fields the constructor will dereference (On_bound_fall, On_bound_land, st_bound_fl, plus eva and eva.vessel). If any required field is null, Hook is skipped and a single deduplicated log line is emitted per condition.

Trade-off: when the prefix skips, first-person EVA bindings won't be installed for that particular Kerbal until something refreshes the FSM. In practice the next vessel switch or scene reload picks up a valid state. No NRE, no log spam.

Build

Requires the .NET SDK with net472 targeting.

dotnet build --configuration Release

Output: bin/Release/TTE_Fix.dll. Drop into a new folder:

<KSP>/GameData/TTE_Fix/TTE_Fix.dll

Clear <KSP>/GameData/ModuleManager.ConfigCache so patches are recomputed on next launch.

Verifying it loaded

The KSP log should contain:

[TTE_Fix] patched EVABoundFix.Hook

If the skip path triggers, you'll see at most one of these lines per distinct cause:

[TTE_Fix] skipped Hook: st_bound_fl is null

Compatibility

• KSP 1.12.5
• Through-The-Eyes 2.0.4.x
• Harmony 2.x

License

GPL-3.0, matching the upstream Through-The-Eyes license.

This repo does not redistribute any Through-The-Eyes code; the patch resolves types via reflection at runtime. Upstream: https://github.com/linuxgurugamer/Through-The-Eyes