When AutoStrutDrift = true an extended piston will move in unexpected ways causing crafts to act unexpectedly

[anth1256]

AutoStrutDrift Bug Piston.zip

Tested with the following:
KSP 1.12.3 DLCs no mods
KSP 1.12.3 DLCs KSPCF/Harmony/modulemanager

KSPCommunityFixes_1.22.2
HarmonyKSP_2.2.1.0_for_KSP1.8+
ModuleManager.4.2.2.dll

Note that this problem happens when the piston is connected one way. If its connected to the other node this problem doesn't happen.

https://youtu.be/UYVAc9oj4Gw Video Evidence

Also note use of timewarp

[gotmachine]

The AutoStrutDrift patch is supposed to skip handling autostruts targeting or originating to/from a servo part, mainly because there is some additional complexity in accounting for the servo current offset that I didn't have the courage to tackle.

But somehow, while I covered the "targeting to a servo" case, I forgot the "originating from a servo" case, resulting in the strut ignoring that the servo is extended and trying to pull it in the retracted position.

I will add the necessary check to fix this.
But ideally, I should try to implement the auto-strut correction even when servo parts are involved. Will try to take a look.

For reference, the fix is replacing this :

KSPCommunityFixes/KSPCommunityFixes/BugFixes/AutoStrutDrift.cs

Lines 32 to 41 in 7147ab0

	// We only correct autostruts directly connected to the main rigidbody of the part.
	// Specifically, we don't handle autostruts connected to a BG robotic part.
	// It might be possible to handle that case by getting the offset between the part and the servoRb, not entirely sure.
	if (joint.connectedBody != anchor.rb)
	{
	#if DEBUG
	Debug.Log($"[AutoStrutDrift] Skipping autostrut for {__instance}. The joint rb ({joint.connectedBody}) isn't the anchor rb ({anchor.rb}), the anchor is likely a robotics part");
	#endif
	return;
	}

with

// We only correct autostruts directly connected to the main rigidbody of the part.
// Specifically, we don't handle autostruts connected from/to a BG robotic part.
// It might be possible to handle that case by getting the offset between the part and the servoRb, not entirely sure.
if (joint.connectedBody.NotDestroyedRefNotEquals(anchor.rb))
{
#if DEBUG
    Debug.Log($"[AutoStrutDrift] Skipping autostrut for {__instance}. The connected rb ({joint.connectedBody}) is different from the anchor rb ({anchor.rb}), the anchor is likely a robotics part");
#endif
    return;
}

if (__instance.Rigidbody.NotDestroyedRefNotEquals(joint.GetComponent<Rigidbody>()))
{
#if DEBUG
    Debug.Log($"[AutoStrutDrift] Skipping autostrut for {__instance}. The part rb ({__instance.Rigidbody}) is different from the rb hosting the joint ({joint.GetComponent<Rigidbody>()}), the part is likely a robotics part");
#endif
    return;
}

[gotmachine]

Fixed in 1.25.2