Catch the exception properly when wvdbusd.dll can't be found.

versaplexd/versaplexd.cs

@@ -73,6 +73,7 @@ static void _StartDBusServerThread(string[] monikers)
     static void StartDBusServerThread(string[] monikers)
     {
 	if (monikers.Length == 0) return;
+	wv.assert(WvDBusServer.check() == 42, "wvdbusd.dll test failed");
 	thread_ready.Reset();
 	dbusserver_thread = new Thread(() => _StartDBusServerThread(monikers));
 	dbusserver_thread.Start();

versaplexd/wvdbusserver.cs

@@ -15,6 +15,14 @@ public class WvDBusServer : IDisposable
     [DllImport("wvdbusd.dll")]
     static extern void wvdbusd_runonce();
 
+    [DllImport("wvdbusd.dll")]
+    static extern int wvdbusd_check();
+
+    public static int check()
+    {
+	return wvdbusd_check();
+    }
+
     public WvDBusServer()
     {
 	wvdbusd_start();

vxodbc/wvdbusd.cc

@@ -42,3 +42,8 @@ extern "C" void wvdbusd_runonce()
     // with.
     s->runonce(1000);
 }
+
+extern "C" int wvdbusd_check()
+{
+    return 42;
+}

vxodbc/wvdbusd.def

@@ -4,3 +4,4 @@ wvdbusd_start @1
 wvdbusd_stop @2
 wvdbusd_listen @3
 wvdbusd_runonce @4
+wvdbusd_check @5

vxodbc/wvdbusd.link

@@ -4,6 +4,7 @@
 	wvdbusd_stop;
 	wvdbusd_listen;
 	wvdbusd_runonce;
+	wvdbusd_check;
     local:
 	*;
 };