1 files changed, 52 insertions, 0 deletions
diff --git a/docshell/test/browser/browser_bug1798780.js b/docshell/test/browser/browser_bug1798780.js
new file mode 100644
index 0000000000..efc0ed9561
--- /dev/null
+++ b/docshell/test/browser/browser_bug1798780.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// The test loads an initial page and then another page which does enough
+// fragment navigations so that when going back to the initial page and then
+// forward to the last page, the initial page is evicted from the bfcache.
+add_task(async function testBFCacheEviction() {
+  // Make an unrealistic large timeout.
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.sessionhistory.contentViewerTimeout", 86400]],
+  });
+
+  const uri = "data:text/html,initial page";
+  const uri2 =
+    getRootDirectory(gTestPath).replace(
+      "chrome://mochitests/content",
+      "https://example.com"
+    ) + "dummy_page.html";
+
+  await BrowserTestUtils.withNewTab(
+    { gBrowser, url: uri },
+    async function (browser) {
+      BrowserTestUtils.loadURIString(browser, uri2);
+      await BrowserTestUtils.browserLoaded(browser);
+
+      let awaitPageShow = BrowserTestUtils.waitForContentEvent(
+        browser,
+        "pageshow"
+      );
+      await SpecialPowers.spawn(browser, [], async function () {
+        content.location.hash = "1";
+        content.location.hash = "2";
+        content.location.hash = "3";
+        content.history.go(-4);
+      });
+
+      await awaitPageShow;
+
+      let awaitPageShow2 = BrowserTestUtils.waitForContentEvent(
+        browser,
+        "pageshow"
+      );
+      await SpecialPowers.spawn(browser, [], async function () {
+        content.history.go(4);
+      });
+      await awaitPageShow2;
+      ok(true, "Didn't time out.");
+    }
+  );
+});