comctl32/treeview: Fix test failure on Vista.
diff --git a/dlls/comctl32/tests/treeview.c b/dlls/comctl32/tests/treeview.c
index 7b45626..3091127 100644
--- a/dlls/comctl32/tests/treeview.c
+++ b/dlls/comctl32/tests/treeview.c
@@ -94,6 +94,7 @@
     { WM_PAINT, sent|defwinproc },
     { WM_IME_SETCONTEXT, sent|defwinproc|optional },
     { WM_COMMAND, sent|wparam|defwinproc, MAKEWPARAM(0, EN_SETFOCUS) },
+    { WM_ERASEBKGND, sent|defwinproc|optional },
     { WM_CTLCOLOREDIT, sent|defwinproc|optional },
     { WM_CTLCOLOREDIT, sent|defwinproc|optional },
     { 0 }