d3d8: Release non implicit surfaces only if refcount is 0, with test.

dlls/d3d8/surface.c

@@ -72,12 +72,14 @@ static ULONG WINAPI IDirect3DSurface8Impl_Release(LPDIRECT3DSURFACE8 iface) {
         ULONG ref = InterlockedDecrement(&This->ref);
         TRACE("(%p) : ReleaseRef to %d\n", This, ref);
 
-        if (ref == 0 && This->parentDevice) IUnknown_Release(This->parentDevice);
+        if (ref == 0) {
+            if (This->parentDevice) IUnknown_Release(This->parentDevice);
             /* Implicit surfaces are destroyed with the device, not if refcount reaches 0. */
-        if (ref >= 0 && !This->isImplicit) {
+            if (!This->isImplicit) {
                 IWineD3DSurface_Release(This->wineD3DSurface);
                 HeapFree(GetProcessHeap(), 0, This);
             }
+        }
 
         return ref;
     }

dlls/d3d8/tests/device.c

@@ -476,10 +476,13 @@ static void test_refcount(void)
     /* Surfaces */
     hr = IDirect3DDevice8_CreateDepthStencilSurface( pDevice, 32, 32, D3DFMT_D24S8, D3DMULTISAMPLE_NONE, &pStencilSurface );
     CHECK_CALL( hr, "CreateDepthStencilSurface", pDevice, ++refcount );
+    CHECK_REFCOUNT( pStencilSurface, 1);
     hr = IDirect3DDevice8_CreateImageSurface( pDevice, 32, 32, D3DFMT_X8R8G8B8, &pImageSurface );
     CHECK_CALL( hr, "CreateImageSurface", pDevice, ++refcount );
+    CHECK_REFCOUNT( pImageSurface, 1);
     hr = IDirect3DDevice8_CreateRenderTarget( pDevice, 32, 32, D3DFMT_X8R8G8B8, D3DMULTISAMPLE_NONE, TRUE, &pRenderTarget3 );
     CHECK_CALL( hr, "CreateRenderTarget", pDevice, ++refcount );
+    CHECK_REFCOUNT( pRenderTarget3, 1);
     /* Misc */
     hr = IDirect3DDevice8_CreateStateBlock( pDevice, D3DSBT_ALL, &dStateBlock );
     CHECK_CALL( hr, "CreateStateBlock", pDevice, refcount );