d3d8: Do not modify the "surface" pointer for D3DFMT_UNKNOWN in d3d8_device_CreateDepthStencilSurface().

Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
diff --git a/dlls/d3d8/device.c b/dlls/d3d8/device.c
index f8eb7ee..9592342 100644
--- a/dlls/d3d8/device.c
+++ b/dlls/d3d8/device.c
@@ -1010,6 +1010,9 @@
     TRACE("iface %p, width %u, height %u, format %#x, multisample_type %#x, surface %p.\n",
             iface, width, height, format, multisample_type, surface);
 
+    if (!format)
+        return D3DERR_INVALIDCALL;
+
     *surface = NULL;
 
     /* TODO: Verify that Discard is false */
diff --git a/dlls/d3d8/tests/device.c b/dlls/d3d8/tests/device.c
index 2295300..45969fe 100644
--- a/dlls/d3d8/tests/device.c
+++ b/dlls/d3d8/tests/device.c
@@ -8218,7 +8218,7 @@
     hr = IDirect3DDevice8_CreateDepthStencilSurface(device, 64, 64,
             D3DFMT_UNKNOWN, D3DMULTISAMPLE_NONE, (IDirect3DSurface8 **)&iface);
     ok(hr == D3DERR_INVALIDCALL, "Got unexpected hr %#x.\n", hr);
-    todo_wine ok(iface == (void *)0xdeadbeef, "Got unexpected iface %p.\n", iface);
+    ok(iface == (void *)0xdeadbeef, "Got unexpected iface %p.\n", iface);
 
     iface = (void *)0xdeadbeef;
     hr = IDirect3DDevice8_CreateImageSurface(device, 64, 64,