From c827cf8e7ecb04e5b1dc95f08752db19b429196f Mon Sep 17 00:00:00 2001
From: Rene <king-sora@hotmail.de>
Date: Sun, 18 Apr 2021 16:08:02 +0200
Subject: [PATCH] fix domobserver bug

---
 .../overlayscrollbars/src/observers/domObserver.ts  | 13 +++++++++----
 .../browser/observers/domObserver/index.browser.ts  |  2 ++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/packages/overlayscrollbars/src/observers/domObserver.ts b/packages/overlayscrollbars/src/observers/domObserver.ts
index ab72f03..666303c 100644
--- a/packages/overlayscrollbars/src/observers/domObserver.ts
+++ b/packages/overlayscrollbars/src/observers/domObserver.ts
@@ -222,8 +222,13 @@ export const createDOMObserver = <ContentObserver extends boolean>(
         contentChanged = contentChanged || contentFinalChanged;
         childListChanged = childListChanged || isChildListType;
       }
-      // else if is target observer and target attr changed
-      else if (attributeChanged && !ignoreTargetChange(mutationTarget, attributeName!, oldValue, attributeValue as string | null)) {
+      // if is target observer and target attr changed
+      if (
+        !isContentObserver &&
+        targetIsMutationTarget &&
+        attributeChanged &&
+        !ignoreTargetChange(mutationTarget, attributeName!, oldValue, attributeValue as string | null)
+      ) {
         push(targetChangedAttrs, attributeName!);
         targetStyleChanged = targetStyleChanged || styleChangingAttrChanged;
       }
@@ -239,8 +244,8 @@ export const createDOMObserver = <ContentObserver extends boolean>(
       );
     }
 
-    if (isContentObserver && contentChanged) {
-      (callback as DOMContentObserverCallback)(contentChanged);
+    if (isContentObserver) {
+      contentChanged && (callback as DOMContentObserverCallback)(contentChanged);
     } else if (!isEmptyArray(targetChangedAttrs) || targetStyleChanged) {
       (callback as DOMTargetObserverCallback)(targetChangedAttrs, targetStyleChanged);
     }
diff --git a/packages/overlayscrollbars/tests/browser/observers/domObserver/index.browser.ts b/packages/overlayscrollbars/tests/browser/observers/domObserver/index.browser.ts
index 12f9018..44ef84c 100644
--- a/packages/overlayscrollbars/tests/browser/observers/domObserver/index.browser.ts
+++ b/packages/overlayscrollbars/tests/browser/observers/domObserver/index.browser.ts
@@ -438,6 +438,8 @@ const addRemoveImgElmsFn = async () => {
     ['img', 'something2'],
     ['img', null],
     ['img', undefined],
+    [null, null],
+    [undefined, undefined],
     ['img', () => 'hi'],
     ['img', () => null],
     ['img', () => undefined],