Don't send SelectionShapeEvent events in the describeCUI/describeLegacyCUI methods, that event is already sent in dispatchCUISelection in LocalSession

src/main/java/com/sk89q/worldedit/regions/ConvexPolyhedralRegionSelector.java

@@ -183,9 +183,7 @@ public class ConvexPolyhedralRegionSelector implements RegionSelector, CUIRegion
     public void describeCUI(LocalSession session, LocalPlayer player) {
         Collection<Vector> vertices = region.getVertices();
         Collection<Triangle> triangles = region.getTriangles();
-
-        player.dispatchCUIEvent(new SelectionShapeEvent(getTypeID()));
-
+        
         Map<Vector, Integer> vertexIds = new HashMap<Vector, Integer>(vertices.size());
         int lastVertexId = -1;
         for (Vector vertex : vertices) {
@@ -212,8 +210,6 @@ public class ConvexPolyhedralRegionSelector implements RegionSelector, CUIRegion
         if (isDefined()) {
             session.dispatchCUIEvent(player, new SelectionPointEvent(0, region.getMinimumPoint(), getArea()));
             session.dispatchCUIEvent(player, new SelectionPointEvent(1, region.getMaximumPoint(), getArea()));
-        } else {
-            session.dispatchCUIEvent(player, new SelectionShapeEvent(getLegacyTypeID()));
         }
     }
 }

src/main/java/com/sk89q/worldedit/regions/CylinderRegionSelector.java

@@ -199,8 +199,6 @@ public class CylinderRegionSelector implements RegionSelector, CUIRegion {
         if (isDefined()) {
             session.dispatchCUIEvent(player, new SelectionPointEvent(0, region.getMinimumPoint(), getArea()));
             session.dispatchCUIEvent(player, new SelectionPointEvent(1, region.getMaximumPoint(), getArea()));
-        } else {
-            session.dispatchCUIEvent(player, new SelectionShapeEvent(getLegacyTypeID()));
         }
     }