From 8178687298626533c48a94aa3099416e0fbbacda Mon Sep 17 00:00:00 2001
From: Steve Halasz <skh2@cornell.edu>
Date: Thu, 10 Sep 2020 17:40:30 -0400
Subject: [PATCH] Better handle destruction when navigator in custom location

---
 src/button.js  | 24 ++++++++++++++++--------
 src/control.js |  4 +++-
 src/viewer.js  | 10 +++++++++-
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/src/button.js b/src/button.js
index 7b00f9ee..5668c871 100644
--- a/src/button.js
+++ b/src/button.js
@@ -399,14 +399,22 @@ $.extend( $.Button.prototype, $.EventSource.prototype, /** @lends OpenSeadragon.
     },
 
     destroy: function() {
-        this.element.removeChild(this.imgRest);
-        this.imgRest = null;
-        this.element.removeChild(this.imgGroup);
-        this.imgGroup = null;
-        this.element.removeChild(this.imgHover);
-        this.imgHover = null;
-        this.element.removeChild(this.imgDown);
-        this.imgDown = null;
+        if (this.imgRest) {
+            this.element.removeChild(this.imgRest);
+            this.imgRest = null;
+        }
+        if (this.imgGroup) {
+            this.element.removeChild(this.imgGroup);
+            this.imgGroup = null;
+        }
+        if (this.imgHover) {
+            this.element.removeChild(this.imgHover);
+            this.imgHover = null;
+        }
+        if (this.imgDown) {
+            this.element.removeChild(this.imgDown);
+            this.imgDown = null;
+        }
         this.removeAllHandlers();
         this.tracker.destroy();
         this.element = null;
diff --git a/src/control.js b/src/control.js
index 64f762d7..6cb229f8 100644
--- a/src/control.js
+++ b/src/control.js
@@ -161,7 +161,9 @@ $.Control.prototype = {
      */
     destroy: function() {
         this.wrapper.removeChild( this.element );
-        this.container.removeChild( this.wrapper );
+        if (this.anchor !== $.ControlAnchor.NONE) {
+            this.container.removeChild(this.wrapper);
+        }
     },
 
     /**
diff --git a/src/viewer.js b/src/viewer.js
index b5b24318..9f6e767a 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -775,7 +775,13 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
         this.removeAllHandlers();
 
         if (this.buttons) {
-            this.buttons.destroy();
+            if (this.buttons instanceof $.ButtonGroup) {
+                this.buttons.destroy();
+            } else {
+                while (this.buttons.length) {
+                    this.buttons.pop().destroy();
+                }
+            }
         }
 
         if (this.paging) {
@@ -1869,6 +1875,8 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
                         {anchor: this.navigationControlAnchor || $.ControlAnchor.TOP_LEFT}
                     );
                 }
+            } else {
+                this.buttons = buttons;
             }
 
         }