Set magic string in registry to enable fallback to full installer in case of 3 stage updates.

chrome/installer/mini_installer/mini_installer.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // mini_installer.exe is the first exe that is run when chrome is being
 // installed or upgraded. It is designed to be extremely small (~5KB with no
 // extra resources linked) and it has two main jobs:
 //   1) unpack the resources (possibly decompressing some)
 //   2) run the real installer (setup.exe) with appropiate flags.
 //
@@ skipping 125 matching lines @@
                       KEY_READ, &key) == ERROR_SUCCESS) &&
       (::RegQueryValueEx(key, value_name, NULL, NULL,
                          reinterpret_cast<LPBYTE>(value),
                          reinterpret_cast<LPDWORD>(&size)) == ERROR_SUCCESS)) {
     ::RegCloseKey(key);
     return true;
   }
   return false;
 }
 
+// This function sets the flag in registry to indicate that Google Update
+// should try full installer next time. If the current installer works, this
+// flag is cleared by setup.exe at the end of install.
+void SetFullInstallerFlag(HKEY root_key) {
+  HKEY key;
+  if (::RegOpenKeyEx(root_key, kApRegistryKey, NULL,
+                     KEY_READ | KEY_SET_VALUE, &key) != ERROR_SUCCESS)

[sra, 2009/06/15 21:20:52]

Does RegOpenKeyEx allow subkeys to be a path with \ separators?  I though that
you needed to open the full path one subkey at a time.  I hope I'm wrong :-)

[kuchhal, 2009/06/15 22:05:31]

It works fine with the full path. I tested the new change as well but we had
been using it like this in the past too.

On 2009/06/15 21:20:52, sra wrote:

+    return;

[sra, 2009/06/15 21:20:52]

Who initially creates the key?  Open will fail if the key does not exist (e.g.
on initial install.)  Is this acceptable?

[kuchhal, 2009/06/15 22:05:31]

Yes it should fail in that case. If it is first install than diff installer
should not be running and we do not need to change magic string.

On 2009/06/15 21:20:52, sra wrote:

+
+  wchar_t value[128];
+  size_t size = _countof(value);
+  if ((::RegQueryValueEx(key, kApRegistryValueName, NULL, NULL,
+                         reinterpret_cast<LPBYTE>(value),
+                         reinterpret_cast<LPDWORD>(&size)) == ERROR_SUCCESS) &&
+      (!StrEndsWith(value, kFullInstallerSuffix)) &&
+      (SafeStrCat(value, size, kFullInstallerSuffix))) {
+    ::RegSetValueEx(key, kApRegistryValueName, 0, REG_SZ,
+                    reinterpret_cast<LPBYTE>(value),
+                    lstrlen(value) * sizeof(wchar_t));
+  }
+
+  ::RegCloseKey(key);
+}
 
 // Gets the setup.exe path from Registry by looking the value of Uninstall
 // string, strips the arguments for uninstall and returns only the full path
 // to setup.exe.
 bool GetSetupExePathFromRegistry(wchar_t *path, size_t size) {
   if (!ReadValueFromRegistry(HKEY_CURRENT_USER, kUninstallRegistryKey,
       kUninstallRegistryValueName, path, size)) {
     if (!ReadValueFromRegistry(HKEY_LOCAL_MACHINE, kUninstallRegistryKey,
         kUninstallRegistryValueName, path, size)) {
       return false;
@@ skipping 309 matching lines @@
 }
 
 // Main function. First gets a working dir, unpacks the resources and finally
 // executes setup.exe to do the install/upgrade.
 int WMain(HMODULE module) {
   // First get a path where we can extract payload
   wchar_t base_path[MAX_PATH];
   if (!GetWorkDir(module, base_path))
     return 101;
 
+  // Set the magic suffix in registry to try full installer next time. We ignore
+  // any errors here and we try to set the suffix for user level as well as
+  // system level.
+  SetFullInstallerFlag(HKEY_LOCAL_MACHINE);
+  SetFullInstallerFlag(HKEY_CURRENT_USER);
+
   wchar_t archive_path[MAX_PATH] = {0};
   wchar_t setup_path[MAX_PATH] = {0};
   if (!UnpackBinaryResources(module, base_path, archive_path, MAX_PATH,
                              setup_path, MAX_PATH))
     return 102;
 
   int exit_code = 103;
   if (!RunSetup(archive_path, setup_path, &exit_code))
     return exit_code;
 
   wchar_t value[4];
   if ((!ReadValueFromRegistry(HKEY_CURRENT_USER, kCleanupRegistryKey,
                               kCleanupRegistryValueName, value, 4)) ||
       (value[0] != L'0'))
     DeleteExtractedFiles(base_path, archive_path, setup_path);
 
   return exit_code;
 }
 }  // namespace mini_installer
 
 
 int MainEntryPoint() {
   int result = mini_installer::WMain(::GetModuleHandle(NULL));
   ::ExitProcess(result);
 }