Bug 1680139 - Stop re-escaping IDN blocklisted characters in uriloader/exthandler/. r=mtigley

Differential Revision: https://phabricator.services.mozilla.com/D134656

uriloader/exthandler/nsExternalHelperAppService.cpp

@@ -153,7 +153,8 @@ static nsresult UnescapeFragment(const nsACString& aFragment, nsIURI* aURI,
       do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  return textToSubURI->UnEscapeURIForUI(aFragment, aResult);
+  return textToSubURI->UnEscapeURIForUI(aFragment, /* aDontEscape = */ true,
+                                        aResult);
 }
 
 /**

uriloader/exthandler/tests/mochitest/browser.ini

@@ -17,6 +17,8 @@ support-files =
 run-if = os == 'linux'
 support-files = download.bin
 [browser_download_always_ask_preferred_app.js]
+[browser_download_idn_blocklist.js]
+support-files = download.bin
 [browser_local_files_no_save_without_asking.js]
 support-files =
   file_pdf_binary_octet_stream.pdf

uriloader/exthandler/tests/mochitest/browser_download_idn_blocklist.js

@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TEST_HOST = "example.org";
+const TEST_FILE = "\u3002.bin";
+const TEST_URL = `http://${TEST_HOST}/${TEST_FILE}`;
+
+const { XPCShellContentUtils } = ChromeUtils.import(
+  "resource://testing-common/XPCShellContentUtils.jsm"
+);
+XPCShellContentUtils.initMochitest(this);
+const server = XPCShellContentUtils.createHttpServer({
+  hosts: [TEST_HOST],
+});
+let file = getChromeDir(getResolvedURI(gTestPath));
+file.append("download.bin");
+server.registerFile(`/${encodeURIComponent(TEST_FILE)}`, file);
+
+/**
+ * Check that IDN blocklisted characters are not escaped in
+ * download file names.
+ */
+add_task(async function test_idn_blocklisted_char_not_escaped() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      // Enable downloads improvements
+      ["browser.download.improvements_to_download_panel", true],
+    ],
+  });
+
+  info("Testing with " + TEST_URL);
+  let publicList = await Downloads.getList(Downloads.PUBLIC);
+  let downloadFinished = promiseDownloadFinished(publicList);
+  var tab = BrowserTestUtils.addTab(gBrowser, TEST_URL);
+  let dl = await downloadFinished;
+  ok(dl.succeeded, "Download should succeed.");
+  Assert.equal(
+    PathUtils.filename(dl.target.path),
+    TEST_FILE,
+    "Should not escape a download file name."
+  );
+  await IOUtils.remove(dl.target.path);
+
+  BrowserTestUtils.removeTab(tab);
+});