1 files changed, 39 insertions, 0 deletions
diff --git a/toolkit/components/thumbnails/test/browser_thumbnails_bg_no_cookies_stored.js b/toolkit/components/thumbnails/test/browser_thumbnails_bg_no_cookies_stored.js
new file mode 100644
index 0000000000..f7acf96ba9
--- /dev/null
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_bg_no_cookies_stored.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Check that if a page captured in the background attempts to set a cookie,
+ * that cookie is not saved for subsequent requests.
+ */
+add_task(async function thumbnails_bg_no_cookies_stored() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["privacy.usercontext.about_newtab_segregation.enabled", true]],
+  });
+  let url = bgTestPageURL({
+    setRedCookie: true,
+    iframe: bgTestPageURL({ setRedCookie: true }),
+    xhr: bgTestPageURL({ setRedCookie: true }),
+  });
+  ok(!thumbnailExists(url), "Thumbnail file should not exist before capture.");
+  await bgCapture(url);
+  ok(thumbnailExists(url), "Thumbnail file should exist after capture.");
+  removeThumbnail(url);
+  // now load it up in a browser - it should *not* be red, otherwise the
+  // cookie above was saved.
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url,
+    },
+    async browser => {
+      // The root element of the page shouldn't be red.
+      await SpecialPowers.spawn(browser, [], function () {
+        Assert.notEqual(
+          content.document.documentElement.style.backgroundColor,
+          "rgb(255, 0, 0)",
+          "The page shouldn't be red."
+        );
+      });
+    }
+  );
+});