BUG: RegQueryInfoKey's lpcbMaxSubKeyLen Returns Incorrect Data

SYMPTOMS

RegQueryInfoKey's lpcbMaxSubKeyLen returns incorrect longest SubKey name length. Sometimes it returns the combined length of all SubKeys in the hierarchy. For example:

1. Create a registry key:

   HKEY_LOCAL_MACHINE\System\Foo\SubKey
   						

   (SubKey is the only SubKey under Foo.)
2. Obtain a handle to:

   HKEY_LOCAL_MACHINE\System\Foo
   					

RegQueryInfoKey API should return the longest subkey name length as 6 for SubKey on Windows NT. In the incorrect case it returns a length of System\Foo\SubKey, which is 17.

NOTE: Under Windows NT, lpcbMaxSubKeyLen count does not include the terminating null character. Under Windows 95 and Windows 98, lpcbMaxSubKeyLen count includes the terminating null character.

   HKEY  hMainKey, hSubKey;
   DWORD dwDisp, dwValues, cbMaxSubKeyLen;

   RegCreateKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\\Foo", 0, REG_NONE,
   REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hMainKey, &dwDisp);

   RegCreateKey(hMainKey, "SubKey", &hSubKey);
   RegCloseKey(hSubKey);
   RegQueryInfoKey (hMainKey, NULL, NULL, NULL, &dwValues, &cbMaxSubKeyLen,
   NULL, NULL, NULL, NULL, NULL, NULL);
   RegCloseKey(hMainKey);
				

   HKEY  hMainKey, hSubKey;
   DWORD dwDisp, dwValues, cbMaxSubKeyLen;

   RegCreateKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\\Foo", 0, REG_NONE,
   REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hMainKey, &dwDisp);

   RegCreateKey(HKEY_LOCAL_MACHINE, "SYSTEM\\Foo\\SubKey", &hSubKey);
   RegCloseKey(hSubKey);
   RegQueryInfoKey (hMainKey, NULL, NULL, NULL, &dwValues, &cbMaxSubKeyLen,
   NULL, NULL, NULL, NULL, NULL, NULL);
   RegCloseKey(hMainKey);