Merge index.js (#34963)

Fix #34960

web_src/js/bootstrap.ts

@@ -20,6 +20,10 @@ function shouldIgnoreError(err: Error) {
 
 export function showGlobalErrorMessage(msg: string, msgType: Intent = 'error') {
   const msgContainer = document.querySelector('.page-content') ?? document.body;
+  if (!msgContainer) {
+    alert(`${msgType}: ${msg}`);
+    return;
+  }
   const msgCompact = msg.replace(/\W/g, '').trim(); // compact the message to a data attribute to avoid too many duplicated messages
   let msgDiv = msgContainer.querySelector<HTMLDivElement>(`.js-global-error[data-global-error-msg-compact="${msgCompact}"]`);
   if (!msgDiv) {