From 53738d969854956207cec4e6f96286ffbe9000fc Mon Sep 17 00:00:00 2001
From: Vladimir Rutsky <rutsky.vladimir@gmail.com>
Date: Wed, 28 Dec 2016 19:50:44 +0300
Subject: [PATCH] raise DeveloperError if drillPick handing detected

---
 Source/Scene/Scene.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Source/Scene/Scene.js b/Source/Scene/Scene.js
index 221e9d5869dd..6d2d76c06786 100644
--- a/Source/Scene/Scene.js
+++ b/Source/Scene/Scene.js
@@ -2703,6 +2703,7 @@ define([
             limit = Number.MAX_VALUE;
         }
 
+        var prevPickedResult = null;
         var pickedResult = this.pick(windowPosition);
         while (defined(pickedResult) && defined(pickedResult.primitive)) {
             result.push(pickedResult);
@@ -2731,7 +2732,16 @@ define([
                 pickedPrimitives.push(primitive);
             }
 
+            prevPickedResult = pickedResult;
             pickedResult = this.pick(windowPosition);
+
+            //>>includeStart('debug', pragmas.debug);
+            if (pickedResult === prevPickedResult) {
+                throw new DeveloperError(
+                  'Failed to hide picked object. ' +
+                  'May be result of improperly handled picking pass by one of the objects.');
+            }
+            //>>includeEnd('debug');
         }
 
         // unhide everything we hid while drill picking