ddraw: Fix and test case for situation where DDSD_MIPMAPCOUNT is set and dwMipMapCount is 0.

dlls/ddraw/ddraw.c

@@ -2417,7 +2417,12 @@ IDirectDrawImpl_CreateSurface(IDirectDraw7 *iface,
         {
             if(desc2.dwFlags & DDSD_MIPMAPCOUNT)
             {
-                /* Mipmap count is given, nothing to do */
+                /* Mipmap count is given, should not be 0 */
+                if( desc2.u2.dwMipMapCount == 0 )
+                {
+                    LeaveCriticalSection(&ddraw_cs);
+                    return DDERR_INVALIDPARAMS;
+                }
             }
             else
             {

dlls/ddraw/tests/dsurface.c

@@ -183,6 +183,25 @@ static void MipMapCreationTest(void)
 
     /* Destroy the surface. */
     IDirectDrawSurface_Release(lpDDSMipMapTest);
+
+
+    /* Fifth mipmap creation test: try to create a surface with
+       DDSCAPS_COMPLEX, DDSCAPS_MIPMAP, DDSD_MIPMAPCOUNT,
+       where dwMipMapCount = 0. This should fail. */
+
+    ddsd.dwSize = sizeof(ddsd);
+    ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT | DDSD_MIPMAPCOUNT;
+    ddsd.ddsCaps.dwCaps = DDSCAPS_TEXTURE | DDSCAPS_COMPLEX | DDSCAPS_MIPMAP;
+    U2(ddsd).dwMipMapCount = 0;
+    ddsd.dwWidth = 128;
+    ddsd.dwHeight = 32;
+    rc = IDirectDraw_CreateSurface(lpDD, &ddsd, &lpDDSMipMapTest, NULL);
+    ok(rc==DDERR_INVALIDPARAMS,"CreateSurface returned: %x\n",rc);
+
+    /* Destroy the surface. */
+    if( rc == DD_OK )
+        IDirectDrawSurface_Release(lpDDSMipMapTest);
+
 }
 
 static void SrcColorKey32BlitTest(void)