1 files changed, 30 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_duplicate_history.js b/browser/components/sessionstore/test/browser_duplicate_history.js
new file mode 100644
index 0000000000..6bb2511390
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_duplicate_history.js
@@ -0,0 +1,30 @@
+ChromeUtils.defineESModuleGetters(this, {
+  SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+  TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
+});
+
+add_task(async function () {
+  await BrowserTestUtils.withNewTab(
+    "http://example.com",
+    async function (aBrowser) {
+      let tab = gBrowser.getTabForBrowser(aBrowser);
+      await TabStateFlusher.flush(aBrowser);
+      let before = TabStateCache.get(aBrowser.permanentKey);
+
+      let newTab = SessionStore.duplicateTab(window, tab);
+      await Promise.all([
+        BrowserTestUtils.browserLoaded(newTab.linkedBrowser),
+        TestUtils.topicObserved("sessionstore-debug-tab-restored"),
+      ]);
+      let after = TabStateCache.get(newTab.linkedBrowser.permanentKey);
+
+      isnot(
+        before.history.entries,
+        after.history.entries,
+        "The entry objects should not be shared"
+      );
+
+      BrowserTestUtils.removeTab(newTab);
+    }
+  );
+});