Allow External Extensions to be installed from HKCU, not just HKLM.

HKLM has priority over HKCU.

BUG=40533
TEST=External Extensions work as before, except now you can also use HKCU now, not just HKLM.
Review URL: http://codereview.chromium.org/7833041

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@101283 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 29 insertions, 14 deletions

diff --git a/chrome/browser/extensions/external_registry_extension_loader_win.cc b/chrome/browser/extensions/external_registry_extension_loader_win.cc
index 86cf311..12f8b76 100644
--- a/chrome/browser/extensions/external_registry_extension_loader_win.cc
+++ b/chrome/browser/extensions/external_registry_extension_loader_win.cc
@@ -17,9 +17,6 @@
 
 namespace {
 
-// The Registry hive where to look for external extensions.
-const HKEY kRegRoot = HKEY_LOCAL_MACHINE;
-
 // The Registry subkey that contains information about external extensions.
 const char kRegistryExtensions[] = "Software\\Google\\Chrome\\Extensions";
 
@@ -49,19 +46,37 @@ void ExternalRegistryExtensionLoader::LoadOnFileThread() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   scoped_ptr<DictionaryValue> prefs(new DictionaryValue);
 
-  base::win::RegistryKeyIterator iterator(
-      kRegRoot, ASCIIToWide(kRegistryExtensions).c_str());
-  for (; iterator.Valid(); ++iterator) {
+  // A map of IDs, to weed out duplicates between HKCU and HKLM.
+  std::set<string16> keys;
+  base::win::RegistryKeyIterator iterator_machine_key(
+      HKEY_LOCAL_MACHINE, ASCIIToWide(kRegistryExtensions).c_str());
+  for (; iterator_machine_key.Valid(); ++iterator_machine_key)
+    keys.insert(iterator_machine_key.Name());
+  base::win::RegistryKeyIterator iterator_user_key(
+      HKEY_CURRENT_USER, ASCIIToWide(kRegistryExtensions).c_str());
+  for (; iterator_user_key.Valid(); ++iterator_user_key)
+    keys.insert(iterator_user_key.Name());
+
+  // Iterate over the keys found, first trying HKLM, then HKCU, as per Windows
+  // policy conventions. We only fall back to HKCU if the HKLM key cannot be
+  // opened, not if the data within the key is invalid, for example.
+  for (std::set<string16>::const_iterator it = keys.begin();
+       it != keys.end(); ++it) {
     base::win::RegKey key;
-    std::wstring key_path = ASCIIToWide(kRegistryExtensions);
+    string16 key_path = ASCIIToWide(kRegistryExtensions);
     key_path.append(L"\\");
-    key_path.append(iterator.Name());
-    if (key.Open(kRegRoot, key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
-      LOG(ERROR) << "Unable to read registry key at path: " << key_path << ".";
-      continue;
+    key_path.append(*it);
+    if (key.Open(HKEY_LOCAL_MACHINE,
+                 key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
+      if (key.Open(HKEY_CURRENT_USER,
+                   key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
+        LOG(ERROR) << "Unable to read registry key at path (HKLM & HKCU): "
+                   << key_path << ".";
+        continue;
+      }
     }
 
-    std::wstring extension_path_str;
+    string16 extension_path_str;
     if (key.ReadValue(kRegistryExtensionPath, &extension_path_str)
         != ERROR_SUCCESS) {
       // TODO(erikkay): find a way to get this into about:extensions
@@ -93,7 +108,7 @@ void ExternalRegistryExtensionLoader::LoadOnFileThread() {
       continue;
     }
 
-    std::wstring extension_version;
+    string16 extension_version;
     if (key.ReadValue(kRegistryExtensionVersion, &extension_version)
         != ERROR_SUCCESS) {
       // TODO(erikkay): find a way to get this into about:extensions
@@ -102,7 +117,7 @@ void ExternalRegistryExtensionLoader::LoadOnFileThread() {
       continue;
     }
 
-    std::string id = WideToASCII(iterator.Name());
+    std::string id = WideToASCII(*it);
     StringToLowerASCII(&id);
     if (!Extension::IdIsValid(id)) {
       LOG(ERROR) << "Invalid id value " << id