Force migrate all clients from multi-install back to single-install.

chrome/installer/mini_installer/configuration.cc

Index: chrome/installer/mini_installer/configuration.cc
diff --git a/chrome/installer/mini_installer/configuration.cc b/chrome/installer/mini_installer/configuration.cc
index 6d20d6d37783c95e16c102247cdcde9cffd3414d..3b5c51af08291a7029885bc4fa374ef9e7f28a0c 100644
--- a/chrome/installer/mini_installer/configuration.cc
+++ b/chrome/installer/mini_installer/configuration.cc
@@ -36,54 +36,10 @@ Configuration::~Configuration() {
   Clear();
 }
 
-// When multi_install is true, we are potentially:
-// 1. Performing a multi-install of some product(s) on a clean machine.
-//    Neither the product(s) nor the multi-installer will have a
-//    ClientState key in the registry, so there is no key to be modified.
-// 2. Upgrading an existing multi-install.  The multi-installer will have
-//    a ClientState key in the registry.  Only it need be modified.
-// 3. Migrating a single-install into a multi-install.  The product will
-//    have a ClientState key in the registry.  Only it need be modified.
-// To handle all cases, we inspect the product's ClientState to see if it
-// exists and its "ap" value does not contain "-multi".  This is case 3,
-// so we modify the product's ClientState.  Otherwise, we check the
-// multi-installer's ClientState and modify it if it exists.
-// TODO(bcwhite): Write a unit test for this that uses registry virtualization.
-void Configuration::SetChromeAppGuid() {
-  const HKEY root_key =
-      is_system_level_ ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
-  const wchar_t* app_guid =
-      is_side_by_side_ ? google_update::kSxSAppGuid
-                       : google_update::kAppGuid;
-
-  // This is the value for single-install and case 3.
-  chrome_app_guid_ = app_guid;
-
-  if (is_multi_install_) {
-    ValueString value;
-    LONG ret = ERROR_SUCCESS;
-    if (ReadClientStateRegistryValue(root_key, app_guid, &ret, value)) {
-      // The product has a client state key.  See if it's a single-install.
-      if (ret == ERROR_FILE_NOT_FOUND ||
-          (ret == ERROR_SUCCESS &&
-           !FindTagInStr(value.get(), kMultiInstallTag, NULL))) {
-        // yes -- case 3: use the existing key.
-        return;
-      }
-    }
-    // error, case 1, or case 2: modify the multi-installer's key.
-    chrome_app_guid_ = google_update::kMultiInstallAppGuid;
-  }
-}
-
-bool Configuration::ReadClientStateRegistryValue(
-    const HKEY root_key, const wchar_t* app_guid,
-    LONG* retval, ValueString& value) {
-  RegKey key;
-  if (!OpenClientStateKey(root_key, app_guid, KEY_QUERY_VALUE, &key))
-    return false;
-  *retval = key.ReadSZValue(kApRegistryValue, value.get(), value.capacity());
-  return true;
+bool Configuration::Initialize(HMODULE module) {
+  Clear();
+  ReadResources(module);
+  return ParseCommandLine(::GetCommandLine());
 }
 
 const wchar_t* Configuration::program() const {
@@ -99,20 +55,13 @@ void Configuration::Clear() {
   command_line_ = NULL;
   operation_ = INSTALL_PRODUCT;
   argument_count_ = 0;
-  has_chrome_ = false;
-  is_multi_install_ = false;
   is_system_level_ = false;
   is_side_by_side_ = false;
+  is_updating_multi_chrome_ = false;
   has_invalid_switch_ = false;
   previous_version_ = NULL;
 }
 
-bool Configuration::Initialize(HMODULE module) {
-  Clear();
-  ReadResources(module);
-  return ParseCommandLine(::GetCommandLine());
-}
-
 // |command_line| is shared with this instance in the sense that this
 // instance may refer to it at will throughout its lifetime, yet it will
 // not release it.
@@ -123,14 +72,12 @@ bool Configuration::ParseCommandLine(const wchar_t* command_line) {
     return false;
 
   for (int i = 1; i < argument_count_; ++i) {
-    if (0 == ::lstrcmpi(args_[i], L"--chrome-sxs"))
-      is_side_by_side_ = true;
-    else if (0 == ::lstrcmpi(args_[i], L"--chrome"))
-      has_chrome_ = true;
-    else if (0 == ::lstrcmpi(args_[i], L"--multi-install"))
-      is_multi_install_ = true;
-    else if (0 == ::lstrcmpi(args_[i], L"--system-level"))
+    if (0 == ::lstrcmpi(args_[i], L"--system-level"))
       is_system_level_ = true;
+#if defined(GOOGLE_CHROME_BUILD)
+    else if (0 == ::lstrcmpi(args_[i], L"--chrome-sxs"))
+      is_side_by_side_ = true;
+#endif
     else if (0 == ::lstrcmpi(args_[i], L"--cleanup"))
       operation_ = CLEANUP;
     else if (0 == ::lstrcmpi(args_[i], L"--chrome-frame"))
@@ -139,9 +86,10 @@ bool Configuration::ParseCommandLine(const wchar_t* command_line) {
 
   if (!is_system_level_)
     is_system_level_ = GetGoogleUpdateIsMachineEnvVar();
-  SetChromeAppGuid();
-  if (!is_multi_install_)
-    has_chrome_ = true;
+  if (is_side_by_side_)
+    chrome_app_guid_ = google_update::kSxSAppGuid;

[gab, 2016/12/12 21:38:16]

Set this in above block on line 79

[grt (UTC plus 2), 2016/12/13 09:20:37]

Done.

+
+  is_updating_multi_chrome_ = IsUpdatingMultiChrome();
 
   return true;
 }
@@ -175,4 +123,42 @@ void Configuration::ReadResources(HMODULE module) {
   previous_version_ = version_string;
 }
 
+LONG Configuration::ReadRegistryValue(RegistryLocation location,
+                                      const wchar_t* app_guid,
+                                      const wchar_t* value_name,
+                                      ValueString* value) const {
+  RegKey key;
+  LONG result = location == RegistryLocation::CLIENTS_KEY
+                    ? OpenClientsKey(is_system_level_ ? HKEY_LOCAL_MACHINE
+                                                      : HKEY_CURRENT_USER,
+                                     app_guid, KEY_QUERY_VALUE, &key)
+                    : OpenClientStateKey(is_system_level_ ? HKEY_LOCAL_MACHINE
+                                                          : HKEY_CURRENT_USER,
+                                         app_guid, KEY_QUERY_VALUE, &key);
+  if (result == ERROR_SUCCESS)
+    result = key.ReadSZValue(value_name, value->get(), value->capacity());
+  return result;
+}
+
+bool Configuration::IsUpdatingMultiChrome() const {

[gab, 2016/12/12 21:38:16]

Writing my assumptions here: 

1) We update from multi:
 * --multi-install is present on uninstall cmd-line of Chrome product.
 * This returns true

2) We update from chrome but still need to cleanup old multi (we can't cleanup
right away as that would make the product disappear during update and GUpdate
wouldn't appreciate?)
 * --multi-install was stripped in (1)
 * This returns false

Correct? Can you point me at where the cleanup phase occurs?

[grt (UTC plus 2), 2016/12/13 09:20:37]

This CL ensures that "--multi-install" on the command line or in
master_preferences is ignored, so it's no longer possible to initiate a multi
install or update. This means that UninstallArguments never contains
"--multi-install" when written in AddUninstallShortcutWorkItems.

And here's the piece that unconditionally deletes the Clients key for the
binaries when doing any single install or update:
https://cs.chromium.org/chromium/src/chrome/installer/setup/install_worker.cc...

So, while there may be multi-install Chrome already present on the machine, it
will be single-install by the time setup.exe exits (unless it exits due to an
error).

As far as the multi-to-single migration being delivered by Google Update via
Chrome's vs. the Binaries' app guids, both are supported. If the update is
delivered via the Binaries app guid, Google Update will think that the product
uninstalled itself during the update. This is the primary way that I monitor the
progress of the migration. :-) The relevant teams know not to scramble when the
particular error code for this spikes.

+#if defined(GOOGLE_CHROME_BUILD)
+  // SxS/canary does not support multi-install.
+  if (is_side_by_side_)
+    return false;
+
+  // Is Chrome already installed as multi-install?
+  ValueString value;
+  return (ReadRegistryValue(RegistryLocation::CLIENTS_KEY,
+                            google_update::kAppGuid, kPvRegistryValue,
+                            &value) == ERROR_SUCCESS &&
+          value.length() != 0 &&
+          ReadRegistryValue(
+              RegistryLocation::CLIENT_STATE_KEY, google_update::kAppGuid,
+              kUninstallArgumentsRegistryValue, &value) == ERROR_SUCCESS &&
+          value.findi(L"--multi-install") != nullptr);
+#else
+  return false;
+#endif
+}
+
 }  // namespace mini_installer