Bug 1705872 - Clear history's epoch in the parent when replacing BC. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D116243
2021-05-29 08:51:47 +00:00 · 2021-05-29 08:51:47 +00:00 · ca3c587dfc
--- a/docshell/base/CanonicalBrowsingContext.cpp
+++ b/docshell/base/CanonicalBrowsingContext.cpp
@ -214,10 +214,10 @@ void CanonicalBrowsingContext::ReplacedBy(

  if (mSessionHistory) {
    mSessionHistory->SetBrowsingContext(aNewContext);
-    if (mozilla::BFCacheInParent()) {
-      // XXXBFCache Should we clear the epoch always?
-      mSessionHistory->SetEpoch(0, Nothing());
-    }
+    // At this point we will be creating a new ChildSHistory in the child.
+    // That means that the child's epoch will be reset, so it makes sense to
+    // reset the epoch in the parent too.
+    mSessionHistory->SetEpoch(0, Nothing());
    mSessionHistory.swap(aNewContext->mSessionHistory);
    RefPtr<ChildSHistory> childSHistory = ForgetChildSHistory();
    aNewContext->SetChildSHistory(childSHistory);
--- a/docshell/test/browser/browser.ini
+++ b/docshell/test/browser/browser.ini
@ -193,3 +193,4 @@ support-files =
 [browser_bug1648464-1.js]
 [browser_bug1688368-1.js]
 [browser_bug1691153.js]
+[browser_bug1705872.js]
--- a/docshell/test/browser/browser_bug1705872.js
+++ b/docshell/test/browser/browser_bug1705872.js
@ -0,0 +1,74 @@
+"use strict";
+
+async function doLoadAndGoBack(browser, ext) {
+  let loaded = BrowserTestUtils.browserLoaded(browser);
+  BrowserTestUtils.loadURI(browser, "https://example.com/");
+  await ext.awaitMessage("redir-handled");
+  await loaded;
+
+  let pageShownPromise = BrowserTestUtils.waitForContentEvent(
+    browser,
+    "pageshow",
+    true
+  );
+  await SpecialPowers.spawn(browser, [], () => {
+    content.history.back();
+  });
+  return pageShownPromise;
+}
+
+add_task(async function test_back() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["webRequest", "webRequestBlocking", "https://example.com/"],
+      web_accessible_resources: ["test.html"],
+    },
+    files: {
+      "test.html":
+        "<!DOCTYPE html><html><head><title>Test add-on</title></head><body></body></html>",
+    },
+    background: () => {
+      let { browser } = this;
+      browser.webRequest.onHeadersReceived.addListener(
+        details => {
+          if (details.statusCode != 200) {
+            return undefined;
+          }
+          browser.test.sendMessage("redir-handled");
+          return { redirectUrl: browser.runtime.getURL("test.html") };
+        },
+        {
+          urls: ["https://example.com/"],
+          types: ["main_frame"],
+        },
+        ["blocking"]
+      );
+    },
+  });
+
+  await extension.startup();
+
+  await BrowserTestUtils.withNewTab("about:home", async function(browser) {
+    await doLoadAndGoBack(browser, extension);
+
+    await SpecialPowers.spawn(browser, [], () => {
+      is(
+        content.document.documentURI,
+        "about:home",
+        "Gone back to the right page"
+      );
+    });
+
+    await doLoadAndGoBack(browser, extension);
+
+    await SpecialPowers.spawn(browser, [], () => {
+      is(
+        content.document.documentURI,
+        "about:home",
+        "Gone back to the right page"
+      );
+    });
+  });
+
+  await extension.unload();
+});