Index: rts/Sim/Units/CommandAI/CommandAI.h
===================================================================
--- rts/Sim/Units/CommandAI/CommandAI.h	(revision 5634)
+++ rts/Sim/Units/CommandAI/CommandAI.h	(working copy)
@@ -81,7 +81,7 @@
 protected:
 	bool isTrackable(const CUnit* unit) const;
 	bool isAttackCapable() const;
-	bool AllowedCommand(const Command &c);
+	virtual bool AllowedCommand(const Command &c);
 	bool SkipParalyzeTarget(const CUnit* target);
 	void GiveAllowedCommand(const Command& c);
 	void GiveWaitCommand(const Command& c);
Index: rts/Sim/Units/CommandAI/TransportCAI.cpp
===================================================================
--- rts/Sim/Units/CommandAI/TransportCAI.cpp	(revision 5634)
+++ rts/Sim/Units/CommandAI/TransportCAI.cpp	(working copy)
@@ -297,6 +297,18 @@
 bool CTransportCAI::FindEmptySpot(float3 center, float radius, float emptyRadius, float3& found, CUnit* unitToUnload)
 {
 	if (dynamic_cast<CTAAirMoveType*>(owner->moveType)) {
+		// If the command radius is less than the diameter of the unit we wish to drop
+		if(radius < emptyRadius*2) {
+			// Boundary checking.  If we are too close to the edge of the map, we will get stuck
+			// in an infinite loop due to not finding any random positions that match a valid location.
+			if	(	(center.x+1*radius < emptyRadius)
+				||	(center.z+1*radius < emptyRadius)
+				||	(center.x-1*radius >= gs->mapx * SQUARE_SIZE - emptyRadius)
+				||	(center.z-1*radius >= gs->mapy * SQUARE_SIZE - emptyRadius)
+				)
+				return false;
+		}
+
 		// handle air transports differently
 		for (int a = 0; a < 100; ++a) {
 			float3 delta(1, 0, 1);
@@ -970,3 +982,25 @@
 		&& unit->pos.distance2D(
 		float3(cmd.params[0], cmd.params[1], cmd.params[2])) > cmd.params[3]*2);
 }
+
+bool CTransportCAI::AllowedCommand(const Command& c)
+{
+	if(!CMobileCAI::AllowedCommand(c))
+		return false;
+
+	switch (c.id) {
+		case CMD_UNLOAD_UNIT:
+		case CMD_UNLOAD_UNITS: {
+			CUnit* u = ((CTransportUnit*) owner)->transported.front().unit;
+			float3 pos(c.params[0],c.params[1],c.params[2]);
+			float radius = c.params[3];
+			float spread = u->radius * ((CTransportUnit*) owner)->unitDef->unloadSpread;
+			float3 found;
+			bool canUnload = FindEmptySpot(pos, max(16.0f, radius), spread, found, u);
+
+			if(!canUnload)	return false;	break;
+		}
+	}
+
+	return true;
+}
Index: rts/Sim/Units/CommandAI/TransportCAI.h
===================================================================
--- rts/Sim/Units/CommandAI/TransportCAI.h	(revision 5634)
+++ rts/Sim/Units/CommandAI/TransportCAI.h	(working copy)
@@ -51,6 +51,7 @@
 	void UnloadLandFlood(Command& c); //land and dispatch units all at once
 	void UnloadCrashFlood(Command& c); //slam into landscape abruptly and dispatch units all at once (incomplete)
 	
+	virtual bool AllowedCommand(const Command& c);
 	bool SpotIsClear(float3 pos, CUnit* u);
 	std::list<float3> dropSpots;		
 	bool isFirstIteration;