dlls/mapi32/tests/mapi32_test.h

   1 /*
   2  * This library is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU Lesser General Public
   4  * License as published by the Free Software Foundation; either
   5  * version 2.1 of the License, or (at your option) any later version.
   6  *
   7  * This library is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  10  * Lesser General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU Lesser General Public
  13  * License along with this library; if not, write to the Free Software
  14  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 /*
  18  * Return FALSE if no default mail client is installed.
  19  */
  20 static BOOL HaveDefaultMailClient(void)
  21 {
  22     HKEY Key;
  23     DWORD Type, Size;
  24     BYTE Buffer[64];
  25     BOOL HasHKCUKey;
  26
  27     /* We check the default value of both HKCU\Software\Clients\Mail and
  28      * HKLM\Software\Clients\Mail, if one of them is present there is a default
  29      * mail client. If neither of these keys is present, we might be running
  30      * on an old Windows version (W95, NT4) and we assume a default mail client
  31      * might be available. Only if one of the keys is present, but there is
  32      * no default value do we assume there is no default client. */
  33     if (RegOpenKeyExA(HKEY_CURRENT_USER, "SOFTWARE\\Clients\\Mail", 0, KEY_QUERY_VALUE, &Key) == ERROR_SUCCESS)
  34     {
  35         Size = sizeof(Buffer);
  36         /* Any return value besides ERROR_FILE_NOT_FOUND (including success,
  37            ERROR_MORE_DATA) indicates the value is present */
  38         if (RegQueryValueExA(Key, NULL, NULL, &Type, Buffer, &Size) != ERROR_FILE_NOT_FOUND)
  39         {
  40             RegCloseKey(Key);
  41             return TRUE;
  42         }
  43         RegCloseKey(Key);
  44         HasHKCUKey = TRUE;
  45     }
  46     else
  47         HasHKCUKey = FALSE;
  48
  49     if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, "SOFTWARE\\Clients\\Mail", 0, KEY_QUERY_VALUE, &Key) == ERROR_SUCCESS)
  50     {
  51         Size = sizeof(Buffer);
  52         if (RegQueryValueExA(Key, NULL, NULL, &Type, Buffer, &Size) != ERROR_FILE_NOT_FOUND)
  53         {
  54             RegCloseKey(Key);
  55             return TRUE;
  56         }
  57         RegCloseKey(Key);
  58         return FALSE;
  59     }
  60
  61     return ! HasHKCUKey;
  62 }