1 files changed, 162 insertions, 0 deletions
diff --git a/browser/components/shell/WindowsDefaultBrowser.cpp b/browser/components/shell/WindowsDefaultBrowser.cpp
new file mode 100644
index 0000000000..34e00be89f
--- /dev/null
+++ b/browser/components/shell/WindowsDefaultBrowser.cpp
@@ -0,0 +1,162 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This file exists so that LaunchModernSettingsDialogDefaultApps can be called
+ * without linking to libxul.
+ */
+#include "WindowsDefaultBrowser.h"
+
+#include "city.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/WindowsVersion.h"
+#include "mozilla/WinHeaderOnlyUtils.h"
+
+// Needed for access to IApplicationActivationManager
+// This must be before any other includes that might include shlobj.h
+#ifdef _WIN32_WINNT
+#  undef _WIN32_WINNT
+#endif
+#define _WIN32_WINNT 0x0600
+#define INITGUID
+#undef NTDDI_VERSION
+#define NTDDI_VERSION NTDDI_WIN8
+#include <shlobj.h>
+
+#include <lm.h>
+#include <shlwapi.h>
+#include <wchar.h>
+#include <windows.h>
+
+#define APP_REG_NAME_BASE L"Firefox-"
+
+static bool IsWindowsLogonConnected() {
+  WCHAR userName[UNLEN + 1];
+  DWORD size = mozilla::ArrayLength(userName);
+  if (!GetUserNameW(userName, &size)) {
+    return false;
+  }
+
+  LPUSER_INFO_24 info;
+  if (NetUserGetInfo(nullptr, userName, 24, (LPBYTE*)&info) != NERR_Success) {
+    return false;
+  }
+  bool connected = info->usri24_internet_identity;
+  NetApiBufferFree(info);
+
+  return connected;
+}
+
+static bool SettingsAppBelievesConnected() {
+  const wchar_t* keyPath = L"SOFTWARE\\Microsoft\\Windows\\Shell\\Associations";
+  const wchar_t* valueName = L"IsConnectedAtLogon";
+
+  uint32_t value = 0;
+  DWORD size = sizeof(uint32_t);
+  LSTATUS ls = RegGetValueW(HKEY_CURRENT_USER, keyPath, valueName, RRF_RT_ANY,
+                            nullptr, &value, &size);
+  if (ls != ERROR_SUCCESS) {
+    return false;
+  }
+
+  return !!value;
+}
+
+bool GetAppRegName(mozilla::UniquePtr<wchar_t[]>& aAppRegName) {
+  mozilla::UniquePtr<wchar_t[]> appDirStr;
+  bool success = GetInstallDirectory(appDirStr);
+  if (!success) {
+    return success;
+  }
+
+  uint64_t hash = CityHash64(reinterpret_cast<char*>(appDirStr.get()),
+                             wcslen(appDirStr.get()) * sizeof(wchar_t));
+
+  const wchar_t* format = L"%s%I64X";
+  int bufferSize = _scwprintf(format, APP_REG_NAME_BASE, hash);
+  ++bufferSize;  // Extra byte for terminating null
+  aAppRegName = mozilla::MakeUnique<wchar_t[]>(bufferSize);
+
+  _snwprintf_s(aAppRegName.get(), bufferSize, _TRUNCATE, format,
+               APP_REG_NAME_BASE, hash);
+
+  return success;
+}
+
+bool LaunchControlPanelDefaultPrograms() {
+  // Build the path control.exe path safely
+  WCHAR controlEXEPath[MAX_PATH + 1] = {'\0'};
+  if (!GetSystemDirectoryW(controlEXEPath, MAX_PATH)) {
+    return false;
+  }
+  LPCWSTR controlEXE = L"control.exe";
+  if (wcslen(controlEXEPath) + wcslen(controlEXE) >= MAX_PATH) {
+    return false;
+  }
+  if (!PathAppendW(controlEXEPath, controlEXE)) {
+    return false;
+  }
+
+  const wchar_t* paramFormat =
+      L"control.exe /name Microsoft.DefaultPrograms "
+      L"/page pageDefaultProgram\\pageAdvancedSettings?pszAppName=%s";
+  mozilla::UniquePtr<wchar_t[]> appRegName;
+  GetAppRegName(appRegName);
+  int bufferSize = _scwprintf(paramFormat, appRegName.get());
+  ++bufferSize;  // Extra byte for terminating null
+  mozilla::UniquePtr<wchar_t[]> params =
+      mozilla::MakeUnique<wchar_t[]>(bufferSize);
+  _snwprintf_s(params.get(), bufferSize, _TRUNCATE, paramFormat,
+               appRegName.get());
+
+  STARTUPINFOW si = {sizeof(si), 0};
+  si.dwFlags = STARTF_USESHOWWINDOW;
+  si.wShowWindow = SW_SHOWDEFAULT;
+  PROCESS_INFORMATION pi = {0};
+  if (!CreateProcessW(controlEXEPath, params.get(), nullptr, nullptr, FALSE, 0,
+                      nullptr, nullptr, &si, &pi)) {
+    return false;
+  }
+  CloseHandle(pi.hProcess);
+  CloseHandle(pi.hThread);
+
+  return true;
+}
+
+bool LaunchModernSettingsDialogDefaultApps() {
+  if (!mozilla::IsWindowsBuildOrLater(14965) && !IsWindowsLogonConnected() &&
+      SettingsAppBelievesConnected()) {
+    // Use the classic Control Panel to work around a bug of older
+    // builds of Windows 10.
+    return LaunchControlPanelDefaultPrograms();
+  }
+
+  IApplicationActivationManager* pActivator;
+  HRESULT hr = CoCreateInstance(
+      CLSID_ApplicationActivationManager, nullptr, CLSCTX_INPROC,
+      IID_IApplicationActivationManager, (void**)&pActivator);
+
+  if (SUCCEEDED(hr)) {
+    DWORD pid;
+    hr = pActivator->ActivateApplication(
+        L"windows.immersivecontrolpanel_cw5n1h2txyewy"
+        L"!microsoft.windows.immersivecontrolpanel",
+        L"page=SettingsPageAppsDefaults", AO_NONE, &pid);
+    if (SUCCEEDED(hr)) {
+      // Do not check error because we could at least open
+      // the "Default apps" setting.
+      pActivator->ActivateApplication(
+          L"windows.immersivecontrolpanel_cw5n1h2txyewy"
+          L"!microsoft.windows.immersivecontrolpanel",
+          L"page=SettingsPageAppsDefaults"
+          L"&target=SystemSettings_DefaultApps_Browser",
+          AO_NONE, &pid);
+    }
+    pActivator->Release();
+    return SUCCEEDED(hr);
+  }
+  return true;
+}