Workaround patch from http://bugs.winehq.org/show_bug.cgi?id=17193

diff --git a/dlls/wined3d/directx.c b/dlls/wined3d/directx.c
index 478c216..52860f9 100644
--- a/dlls/wined3d/directx.c
+++ b/dlls/wined3d/directx.c
@@ -793,9 +793,6 @@ static BOOL IWineD3DImpl_FillGLCaps(WineD3D_GL_Info *gl_info) {
             else gl_info->pfn = NULL; \
         }
         GL_EXT_FUNCS_GEN;
-#undef USE_GL_FUNC
-
-#define USE_GL_FUNC(type, pfn, ext, replace) gl_info->pfn = (type) pwglGetProcAddress(#pfn);
         WGL_EXT_FUNCS_GEN;
 #undef USE_GL_FUNC
 
@@ -1399,12 +1396,14 @@ static BOOL IWineD3DImpl_FillGLCaps(WineD3D_GL_Info *gl_info) {
     /* Make sure there's an active HDC else the WGL extensions will fail */
     hdc = pwglGetCurrentDC();
     if (hdc) {
-        WGL_Extensions = GL_EXTCALL(wglGetExtensionsStringARB(hdc));
-        TRACE_(d3d_caps)("WGL_Extensions reported:\n");
-
-        if (NULL == WGL_Extensions) {
-            ERR("   WGL_Extensions returns NULL\n");
+        if (! GL_EXTCALL(wglGetExtensionsStringARB)) {
+            TRACE_(d3d_caps)("wglGetExtensionsStringARB is unavailable\n");
         } else {
+	    WGL_Extensions = GL_EXTCALL(wglGetExtensionsStringARB(hdc));
+            if (NULL == WGL_Extensions)
+                ERR("   WGL_Extensions returns NULL\n");
+
+            TRACE_(d3d_caps)("WGL_Extensions reported:\n");
             while (*WGL_Extensions != 0x00) {
                 const char *Start;
                 char ThisExtn[256];
@@ -4287,7 +4286,12 @@ BOOL InitAdapters(void) {
         strcpyW(Adapters[0].DeviceName, DisplayDevice.DeviceName);
 
         attribute = WGL_NUMBER_PIXEL_FORMATS_ARB;
-        GL_EXTCALL(wglGetPixelFormatAttribivARB(hdc, 0, 0, 1, &attribute, &Adapters[0].nCfgs));
+        if (GL_EXTCALL(wglGetPixelFormatAttribivARB))
+            GL_EXTCALL(wglGetPixelFormatAttribivARB(hdc, 0, 0, 1, &attribute, &Adapters[0].nCfgs));
+        else {
+            TRACE("wglGetPixelFormatAttribivARB is unavailable\n");
+            Adapters[0].nCfgs = 0;
+        }
 
         Adapters[0].cfgs = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, Adapters[0].nCfgs *sizeof(WineD3D_PixelFormat));
         cfgs = Adapters[0].cfgs;