Update History tab can now be restored.

src/client/js/app.jsx

@@ -123,8 +123,8 @@ if (pageContainer.state.pageId != null) {
   });
 
   // show the Page accessory modal when query of "compare" is requested
-  if (pageContainer.state.compareRevisionIds != null && pageContainer.state.compareRevisionIds.length > 0) {
-    pageAccessoriesContainer.openPageAccessoriesModal('revisionCompare');
+  if (pageContainer.compareRevisionIds.length > 0) {
+    pageAccessoriesContainer.openPageAccessoriesModal('pageHistory');
   }
 }
 if (pageContainer.state.creator != null) {

src/client/js/services/PageContainer.js

@@ -632,4 +632,17 @@ export default class PageContainer extends Container {
   retrieveMyBookmarkList() {
   }
 
+  get compareRevisionIds() {
+    const searchParams = {};
+    for (const param of window.location.search?.substr(1)?.split('&')) {
+      const [k,v] = param.split('=');
+      searchParams[k] = v;
+    }
+    if (!searchParams['compare']) {
+      return [];
+    }
+
+    return searchParams['compare'].split('...') || [];
+  }
+
 }