[PATCH v2 4/7] wintab32: Use registry to query primary adapter key.

[Zhiyi Zhang]

Signed-off-by: Zhiyi Zhang <zzhang at codeweavers.com>
---
 dlls/wintab32/wintab32.c | 60 +++++++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 16 deletions(-)

diff --git a/dlls/wintab32/wintab32.c b/dlls/wintab32/wintab32.c
index fe535fa1af..d9325899be 100644
--- a/dlls/wintab32/wintab32.c
+++ b/dlls/wintab32/wintab32.c
@@ -72,30 +72,58 @@ static VOID TABLET_Unregister(void)
     UnregisterClassW(WC_TABLETCLASSNAME, NULL);
 }
 
+/* Get the primary adapter key in the form of System\CurrentControlSet\Control\Video\{Primary adapter GUID}\0000 */
+static BOOL get_primary_adapter_key(WCHAR *key, int len)
+{
+    static const WCHAR video_keyW[] = {'H','A','R','D','W','A','R','E','\\',
+                                       'D','E','V','I','C','E','M','A','P','\\',
+                                       'V','I','D','E','O',0};
+    static const WCHAR device_video0W[] = {'\\','D','e','v','i','c','e','\\',
+                                           'V','i','d','e','o','0',0};
+    static const WCHAR value_prefixW[] = {'\\','R','e','g','i','s','t','r','y','\\',
+                                          'M','a','c','h','i','n','e','\\',0};
+    WCHAR buffer[MAX_PATH];
+    WCHAR *substring;
+    DWORD size;
+    int length;
+    BOOL ret = FALSE;
+
+    /* Vaule data of \Device\Video0 in HKLM\HARDWARE\DEVICEMAP\VIDEO\ */
+    size = sizeof(buffer);
+    if (RegGetValueW(HKEY_LOCAL_MACHINE, video_keyW, device_video0W, RRF_RT_REG_SZ | RRF_ZEROONFAILURE, NULL, buffer,
+                     &size))
+        goto fail;
+
+    /* Need to strip "\Registry\Machine\" from the value data, which starts with "\Registry\Machine\System\..." */
+    length = strlenW(value_prefixW);
+    if (strncmpiW(buffer, value_prefixW, length))
+        goto fail;
+
+    substring = buffer + length;
+    length = strlenW(substring);
+    if (len < length + 1)
+        goto fail;
+
+    strcpyW(key, substring);
+
+    ret = TRUE;
+    TRACE("primary adapter key %s\n", wine_dbgstr_w(key));
+fail:
+    if (!ret)
+        ERR("Failed to get primary adapter registry key\n");
+    return ret;
+}
+
 static HMODULE load_graphics_driver(void)
 {
-    static const WCHAR display_device_guid_propW[] = {
-        '_','_','w','i','n','e','_','d','i','s','p','l','a','y','_',
-        'd','e','v','i','c','e','_','g','u','i','d',0 };
-    static const WCHAR key_pathW[] = {
-        'S','y','s','t','e','m','\\',
-        'C','u','r','r','e','n','t','C','o','n','t','r','o','l','S','e','t','\\',
-        'C','o','n','t','r','o','l','\\',
-        'V','i','d','e','o','\\','{',0};
-    static const WCHAR displayW[] = {'}','\\','0','0','0','0',0};
     static const WCHAR driverW[] = {'G','r','a','p','h','i','c','s','D','r','i','v','e','r',0};
-
     HMODULE ret = 0;
     HKEY hkey;
     DWORD size;
     WCHAR path[MAX_PATH];
-    WCHAR key[ARRAY_SIZE(key_pathW) + ARRAY_SIZE(displayW) + 40];
-    UINT guid_atom = HandleToULong( GetPropW( GetDesktopWindow(), display_device_guid_propW ));
+    WCHAR key[MAX_PATH];
 
-    if (!guid_atom) return 0;
-    memcpy( key, key_pathW, sizeof(key_pathW) );
-    if (!GlobalGetAtomNameW( guid_atom, key + strlenW(key), 40 )) return 0;
-    strcatW( key, displayW );
+    if (!get_primary_adapter_key( key, ARRAY_SIZE(key ))) return 0;
     if (RegOpenKeyW( HKEY_LOCAL_MACHINE, key, &hkey )) return 0;
     size = sizeof(path);
     if (!RegQueryValueExW( hkey, driverW, NULL, NULL, (BYTE *)path, &size )) ret = LoadLibraryW( path );
-- 
2.20.1