Return Windows error code when create-process fails.

chrome/installer/mini_installer/regkey.cc

+// Copyright (c) 2012 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.
+
+#include "chrome/installer/mini_installer/regkey.h"
+
+#include "chrome/installer/mini_installer/mini_installer_constants.h"
+#include "chrome/installer/mini_installer/mini_string.h"
+
+namespace mini_installer {
+
+LONG RegKey::Open(HKEY key, const wchar_t* sub_key, REGSAM access) {
+  Close();
+  return ::RegOpenKeyEx(key, sub_key, NULL, access, &key_);
+}
+
+LONG RegKey::ReadSZValue(const wchar_t* value_name,
+                         wchar_t* value,
+                         size_t value_size) const {
+  DWORD type = 0;
+  DWORD byte_length = static_cast<DWORD>(value_size * sizeof(wchar_t));
+  LONG result = ::RegQueryValueEx(key_, value_name, NULL, &type,
+                                  reinterpret_cast<BYTE*>(value),
+                                  &byte_length);
+  if (result == ERROR_SUCCESS) {
+    if (type != REG_SZ) {
+      result = ERROR_NOT_SUPPORTED;
+    } else if (byte_length == 0) {
+      *value = L'\0';
+    } else if (value[byte_length/sizeof(wchar_t) - 1] != L'\0') {
+      if ((byte_length / sizeof(wchar_t)) < value_size)
+        value[byte_length / sizeof(wchar_t)] = L'\0';
+      else
+        result = ERROR_MORE_DATA;
+    }
+  }
+  return result;
+}
+
+LONG RegKey::ReadDWValue(const wchar_t* value_name, DWORD* value) const {
+  DWORD type = 0;
+  DWORD byte_length = sizeof(*value);
+  LONG result = ::RegQueryValueEx(key_, value_name, NULL, &type,
+                                  reinterpret_cast<BYTE*>(value),
+                                  &byte_length);
+  if (result == ERROR_SUCCESS) {
+    if (type != REG_DWORD) {
+      result = ERROR_NOT_SUPPORTED;
+    } else if (byte_length != sizeof(*value)) {
+      result = ERROR_NO_DATA;
+    }
+  }
+  return result;
+}
+
+LONG RegKey::WriteSZValue(const wchar_t* value_name, const wchar_t* value) {
+  return ::RegSetValueEx(key_, value_name, 0, REG_SZ,
+                         reinterpret_cast<const BYTE*>(value),
+                         (lstrlen(value) + 1) * sizeof(wchar_t));
+}
+
+LONG RegKey::WriteDWValue(const wchar_t* value_name, DWORD value) {
+  return ::RegSetValueEx(key_, value_name, 0, REG_DWORD,
+                         reinterpret_cast<const BYTE*>(&value),
+                         sizeof(value));
+}
+
+void RegKey::Close() {
+  if (key_ != NULL) {
+    ::RegCloseKey(key_);
+    key_ = NULL;
+  }
+}
+
+
+// static
+bool RegKey::ReadSZValue(HKEY root_key, const wchar_t *sub_key,
+                         const wchar_t *value_name, wchar_t *value,
+                         size_t size) {
+  RegKey key;
+  return (key.Open(root_key, sub_key, KEY_QUERY_VALUE) == ERROR_SUCCESS &&
+          key.ReadSZValue(value_name, value, size) == ERROR_SUCCESS);
+}
+
+// Opens the Google Update ClientState key for a product.  This finds only
+// registry entries for Chrome; it does not support the Chromium registry
+// layout.
+bool OpenClientStateKey(HKEY root_key, const wchar_t* app_guid,
+                        REGSAM access, RegKey* key) {
+  StackString<MAX_PATH> client_state_key;
+  return client_state_key.assign(kClientStateKeyBase) &&
+         client_state_key.append(app_guid) &&
+         (key->Open(root_key,
+                    client_state_key.get(),
+                    access | KEY_WOW64_32KEY) == ERROR_SUCCESS);
+}
+
+}  // namespace mini_installer