From 8c78994866430c1e56212bba1e1c3ff3ce62e77d Mon Sep 17 00:00:00 2001
From: Alexandre Julliard <julliard@winehq.org>
Date: Wed, 8 Dec 2010 20:32:08 +0100
Subject: [PATCH] widl: Signal an error when trying to output an undefined
 interface into a typelib.

---
 tools/widl/write_msft.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/widl/write_msft.c b/tools/widl/write_msft.c
index 309145fa571..d76244558e2 100644
--- a/tools/widl/write_msft.c
+++ b/tools/widl/write_msft.c
@@ -2014,6 +2014,12 @@ static void add_interface_typeinfo(msft_typelib_t *typelib, type_t *interface)
     if (-1 < interface->typelib_idx)
         return;
 
+    if (!interface->details.iface)
+    {
+        error( "interface %s is referenced but not defined\n", interface->name );
+        return;
+    }
+
     if (is_attr(interface->attrs, ATTR_DISPINTERFACE))
         return add_dispinterface_typeinfo(typelib, interface);