Index: ps/trunk/binaries/data/mods/public/simulation/helpers/Commands.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/helpers/Commands.js
+++ ps/trunk/binaries/data/mods/public/simulation/helpers/Commands.js
@@ -1559,20 +1559,20 @@
  */
 function ClusterEntities(ents, separationDistance)
 {
-	var clusters = [];
+	let clusters = [];
 	if (!ents.length)
 		return clusters;
 
-	var distSq = separationDistance * separationDistance;
-	var positions = [];
+	let distSq = separationDistance * separationDistance;
+	let positions = [];
 	// triangular matrix with the (squared) distances between the different clusters
 	// the other half is not initialised
-	var matrix = [];
+	let matrix = [];
 	for (let i = 0; i < ents.length; ++i)
 	{
 		matrix[i] = [];
 		clusters.push([ents[i]]);
-		var cmpPosition = Engine.QueryInterface(ents[i], IID_Position);
+		let cmpPosition = Engine.QueryInterface(ents[i], IID_Position);
 		positions.push(cmpPosition.GetPosition2D());
 		for (let j = 0; j < i; ++j)
 			matrix[i][j] = positions[i].distanceToSquared(positions[j]);
@@ -1580,10 +1580,10 @@
 	while (clusters.length > 1)
 	{
 		// search two clusters that are closer than the required distance
-		var closeClusters = undefined;
+		let closeClusters = undefined;
 
-		for (var i = matrix.length - 1; i >= 0 && !closeClusters; --i)
-			for (var j = i - 1; j >= 0 && !closeClusters; --j)
+		for (let i = matrix.length - 1; i >= 0 && !closeClusters; --i)
+			for (let j = i - 1; j >= 0 && !closeClusters; --j)
 				if (matrix[i][j] < distSq)
 					closeClusters = [i,j];
 
@@ -1592,17 +1592,19 @@
 			return clusters;
 
 		// make a new cluster with the entities from the two found clusters
-		var newCluster = clusters[closeClusters[0]].concat(clusters[closeClusters[1]]);
+		let newCluster = clusters[closeClusters[0]].concat(clusters[closeClusters[1]]);
 
 		// calculate the minimum distance between the new cluster and all other remaining
 		// clusters by taking the minimum of the two distances.
-		var distances = [];
+		let distances = [];
 		for (let i = 0; i < clusters.length; ++i)
 		{
-			if (i == closeClusters[1] || i == closeClusters[0])
+			let a = closeClusters[1];
+			let b = closeClusters[0];
+			if (i == a || i == b)
 				continue;
-			var dist1 = matrix[closeClusters[1]][i] || matrix[i][closeClusters[1]];
-			var dist2 = matrix[closeClusters[0]][i] || matrix[i][closeClusters[0]];
+			let dist1 = matrix[a][i] !== undefined ? matrix[a][i] : matrix[i][a];
+			let dist2 = matrix[b][i] !== undefined ? matrix[b][i] : matrix[i][b];
 			distances.push(Math.min(dist1, dist2));
 		}
 		// remove the rows and columns in the matrix for the merged clusters,