MDL-67513 core: Only move modal to body if currently attached

A previous change as part of this commitset was intended to move the
modal to the document.body, but where the modal had been destroyed it
was instead added back to the body.

lib/amd/build/modal_backdrop.min.js

@@ -1,2 +1,2 @@
-define ("core/modal_backdrop",["jquery","core/templates","core/notification","core/fullscreen"],function(a,b,c,d){var e={ROOT:"[data-region=\"modal-backdrop\"]"},f=function(b){this.root=a(b);this.isAttached=!1;if(!this.root.is(e.ROOT)){c.exception({message:"Element is not a modal backdrop"})}};f.prototype.getRoot=function(){return this.root};f.prototype.getAttachmentPoint=function(){return a(d.getElement()||document.body)};f.prototype.attachToDOM=function(){this.getAttachmentPoint().append(this.root);if(this.isAttached){return}this.isAttached=!0};f.prototype.setZIndex=function(a){this.root.css("z-index",a)};f.prototype.isVisible=function(){return this.root.hasClass("show")};f.prototype.hasTransitions=function(){return this.getRoot().hasClass("fade")};f.prototype.show=function(){if(this.isVisible()){return}this.attachToDOM();this.root.removeClass("hide").addClass("show")};f.prototype.hide=function(){if(!this.isVisible()){return}if(this.hasTransitions()){this.getRoot().one("transitionend webkitTransitionEnd oTransitionEnd",function(){this.getRoot().removeClass("show").addClass("hide")}.bind(this))}else{this.getRoot().removeClass("show").addClass("hide")}a(document.body).append(this.getRoot())};f.prototype.destroy=function(){this.root.remove()};return f});
+define ("core/modal_backdrop",["jquery","core/templates","core/notification","core/fullscreen"],function(a,b,c,d){var e={ROOT:"[data-region=\"modal-backdrop\"]"},f=function(b){this.root=a(b);this.isAttached=!1;if(!this.root.is(e.ROOT)){c.exception({message:"Element is not a modal backdrop"})}};f.prototype.getRoot=function(){return this.root};f.prototype.getAttachmentPoint=function(){return a(d.getElement()||document.body)};f.prototype.attachToDOM=function(){this.getAttachmentPoint().append(this.root);if(this.isAttached){return}this.isAttached=!0};f.prototype.setZIndex=function(a){this.root.css("z-index",a)};f.prototype.isVisible=function(){return this.root.hasClass("show")};f.prototype.hasTransitions=function(){return this.getRoot().hasClass("fade")};f.prototype.show=function(){if(this.isVisible()){return}this.attachToDOM();this.root.removeClass("hide").addClass("show")};f.prototype.hide=function(){if(!this.isVisible()){return}if(this.hasTransitions()){this.getRoot().one("transitionend webkitTransitionEnd oTransitionEnd",function(){this.getRoot().removeClass("show").addClass("hide")}.bind(this))}else{this.getRoot().removeClass("show").addClass("hide")}if(a(document.body).find(this.getRoot()).length){a(document.body).append(this.getRoot())}};f.prototype.destroy=function(){this.root.remove()};return f});
 //# sourceMappingURL=modal_backdrop.min.js.map

lib/amd/src/modal.js

@@ -735,8 +735,10 @@ define([
                 this.getRoot().removeClass('show').addClass('hide');
             }
 
-            // Ensure the modal is moved onto the body node.
-            $(document.body).append(this.getRoot());
+            // Ensure the modal is moved onto the body node if it is still attached to the DOM.
+            if ($(document.body).find(this.getRoot()).length) {
+                $(document.body).append(this.getRoot());
+            }
 
             this.root.trigger(ModalEvents.hidden, this);
         }.bind(this));

lib/amd/src/modal_backdrop.js

@@ -142,8 +142,10 @@ define(['jquery', 'core/templates', 'core/notification', 'core/fullscreen'],
             this.getRoot().removeClass('show').addClass('hide');
         }
 
-        // Ensure the modal is moved back onto the body node.
-        $(document.body).append(this.getRoot());
+        // Ensure the modal is moved onto the body node if it is still attached to the DOM.
+        if ($(document.body).find(this.getRoot()).length) {
+            $(document.body).append(this.getRoot());
+        }
     };
 
     /**