Popper: fix memory leak on route change (#9757)

src/utils/popper.js

@@ -240,7 +240,6 @@
         if (typeof this.state.updateCallback === 'function') {
             this.state.updateCallback(data);
         }
-
     };
 
     /**
@@ -438,7 +437,6 @@
         popperOffsets.width   = popperRect.width;
         popperOffsets.height  = popperRect.height;
 
-
         return {
             popper: popperOffsets,
             reference: referenceOffsets
@@ -464,6 +462,7 @@
                 target = root;
             }
             target.addEventListener('scroll', this.state.updateBound);
+            this.state.scrollTarget = target;
         }
     };
 
@@ -476,13 +475,9 @@
     Popper.prototype._removeEventListeners = function() {
         // NOTE: 1 DOM access here
         root.removeEventListener('resize', this.state.updateBound);
-        if (this._options.boundariesElement !== 'window') {
-            var target = getScrollParent(this._reference);
-            // here it could be both `body` or `documentElement` thanks to Firefox, we then check both
-            if (target === root.document.body || target === root.document.documentElement) {
-                target = root;
-            }
-            target.removeEventListener('scroll', this.state.updateBound);
+        if (this._options.boundariesElement !== 'window' && this.state.scrollTarget) {
+            this.state.scrollTarget.removeEventListener('scroll', this.state.updateBound);
+            this.state.scrollTarget = null;
         }
         this.state.updateBound = null;
     };

src/utils/vue-popper.js

@@ -129,9 +129,9 @@ export default {
       }
     },
 
-    doDestroy() {
+    doDestroy(forceDestroy) {
       /* istanbul ignore if */
-      if (this.showPopper || !this.popperJS) return;
+      if (!this.popperJS || (this.showPopper && !forceDestroy)) return;
       this.popperJS.destroy();
       this.popperJS = null;
     },
@@ -184,7 +184,7 @@ export default {
   },
 
   beforeDestroy() {
-    this.doDestroy();
+    this.doDestroy(true);
     if (this.popperElm && this.popperElm.parentNode === document.body) {
       this.popperElm.removeEventListener('click', stop);
       document.body.removeChild(this.popperElm);