Delay window.scrollBy in handleLocationHash to fix FF bug

Closes #19132

app/assets/javascripts/lib/utils/common_utils.js

@@ -135,7 +135,9 @@ export const handleLocationHash = () => {
     adjustment -= topPadding;
   }
 
+  setTimeout(() => {
     window.scrollBy(0, adjustment);
+  });
 };
 
 // Check if element scrolled into viewport from above or below

changelogs/unreleased/19132-comment-anchor-twice-firefox.yml

+---
+title: Fix bug when clicking on same note twice in Firefox
+merge_request: 21699
+author: Jan Beckmann
+type: fixed

spec/javascripts/lib/utils/common_utils_spec.js

@@ -88,10 +88,12 @@ describe('common_utils', () => {
   describe('handleLocationHash', () => {
     beforeEach(() => {
       spyOn(window.document, 'getElementById').and.callThrough();
+      jasmine.clock().install();
     });
 
     afterEach(() => {
       window.history.pushState({}, null, '');
+      jasmine.clock().uninstall();
     });
 
     function expectGetElementIdToHaveBeenCalledWith(elementId) {
@@ -171,6 +173,7 @@ describe('common_utils', () => {
 
       window.history.pushState({}, null, '#test');
       commonUtils.handleLocationHash();
+      jasmine.clock().tick(1);
 
       expectGetElementIdToHaveBeenCalledWith('test');
       expectGetElementIdToHaveBeenCalledWith('user-content-test');