Fix relto-plunge

Looks like the fissure fall camera region got triggered then untriggered
during the linking process. In debug builds, this happened in one frame,
so only an exit message got sent out. In faster builds, both would be
sent, and you would plunge. To fix that, we don't send eval until we're no
longer MidLink.

Sources/Plasma/PubUtilLib/plPhysical/plCollisionDetector.cpp

@@ -73,6 +73,9 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 
 plArmatureMod* plCollisionDetector::IGetAvatarModifier(plKey key)
 {
+    if (!key)
+        return nil;
+
     plSceneObject* avObj = plSceneObject::ConvertNoRef(key->ObjectIsLoaded());
     if (avObj)
     {
@@ -242,8 +245,6 @@ plCameraRegionDetector::~plCameraRegionDetector()
 
 void plCameraRegionDetector::ITrigger(plKey hitter, bool entering, bool immediate)
 {
-    if (fSavingSendMsg)
-        DetectorLogRed("%s: Stale messages on ITrigger. This should never happen!", GetKeyName().c_str());
     if (fIsInside && entering)
         DetectorLogRed("%s: Duplicate enter! Did we miss an exit?", GetKeyName().c_str());
     else if (!fIsInside && !entering)
@@ -384,11 +385,18 @@ hsBool plObjectInVolumeDetector::MsgReceive(plMessage* msg)
     plCollideMsg* pCollMsg = plCollideMsg::ConvertNoRef(msg);
     if (pCollMsg)
     {
+        fLastHitter = pCollMsg->fOtherKey;
         // If the avatar is disabled (flying around), don't trigger
-        if (IIsDisabledAvatar(pCollMsg->fOtherKey))
+        if (IIsDisabledAvatar(fLastHitter))
             return false;
-        ITrigger(pCollMsg->fOtherKey, (pCollMsg->fEntering != 0));
+        ITrigger(fLastHitter, (pCollMsg->fEntering != 0));
+
+        // If we never eval before the exit...
+        if (fWaitingForEval)
+            plgDispatch::Dispatch()->UnRegisterForExactType(plEvalMsg::Index(), GetKey());
+        else
             plgDispatch::Dispatch()->RegisterForExactType(plEvalMsg::Index(), GetKey());
+        fWaitingForEval = !fWaitingForEval;
         return true;
     }
 
@@ -396,8 +404,13 @@ hsBool plObjectInVolumeDetector::MsgReceive(plMessage* msg)
     if (pEvalMsg)
     {
         fNumEvals++;
+        // Don't dispatch if we're not in the age
+        if (plArmatureMod* av = IGetAvatarModifier(fLastHitter))
+            if (av->IsMidLink())
+                return true;
         ISendSavedTriggerMsgs();
         plgDispatch::Dispatch()->UnRegisterForExactType(plEvalMsg::Index(), GetKey());
+        fWaitingForEval = false;
     }
 
     plPlayerPageMsg* pageMsg = plPlayerPageMsg::ConvertNoRef(msg);

Sources/Plasma/PubUtilLib/plPhysical/plCollisionDetector.h

@@ -99,15 +99,19 @@ protected:
     uint32_t fNumEvals;
     uint32_t fLastEnterEval;
     uint32_t fLastExitEval;
+    bool     fWaitingForEval;
+    plKey    fLastHitter;
 
 public:
     
     plObjectInVolumeDetector() 
-        : plCollisionDetector(), fSavedActivatorMsg(nil), fNumEvals(0), fLastEnterEval(0), fLastExitEval(0) 
+        : plCollisionDetector(), fSavedActivatorMsg(nil), fNumEvals(0), fLastEnterEval(0),
+          fWaitingForEval(false), fLastHitter(nil)
     { }
 
     plObjectInVolumeDetector(int8_t type) 
-        : plCollisionDetector(type), fSavedActivatorMsg(nil), fNumEvals(0), fLastEnterEval(0), fLastExitEval(0) 
+        : plCollisionDetector(type), fSavedActivatorMsg(nil), fNumEvals(0), fLastEnterEval(0),
+          fWaitingForEval(false), fLastHitter(nil)
     { }
 
     virtual ~plObjectInVolumeDetector() { }