urlmon: Fixed handling NULL URLName in GetDisplatName implementation.

dlls/urlmon/tests/url.c

@@ -2574,6 +2574,7 @@ static void test_BindToStorage_fail(void)
 static void test_StdURLMoniker(void)
 {
     IMoniker *mon, *async_mon;
+    LPOLESTR display_name;
     HRESULT hres;
 
     hres = CoCreateInstance(&IID_IInternet, NULL, CLSCTX_INPROC_SERVER|CLSCTX_INPROC_HANDLER,
@@ -2587,6 +2588,9 @@ static void test_StdURLMoniker(void)
     ok(mon == async_mon, "mon != async_mon\n");
     IMoniker_Release(async_mon);
 
+    hres = IMoniker_GetDisplayName(mon, NULL, NULL, &display_name);
+    ok(hres == E_OUTOFMEMORY, "GetDisplayName failed: %08x, expected E_OUTOFMEMORY\n", hres);
+
     IMoniker_Release(mon);
 }
 
@@ -2641,7 +2645,7 @@ START_TEST(url)
 
         CoInitialize(NULL);
 
-        trace("test StdURLMoniker...");
+        trace("test StdURLMoniker...\n");
         test_StdURLMoniker();
 
         trace("synchronous http test...\n");

dlls/urlmon/umon.c

@@ -377,6 +377,9 @@ static HRESULT WINAPI URLMoniker_GetDisplayName(IMoniker *iface, IBindCtx *pbc,
     if(!ppszDisplayName)
         return E_INVALIDARG;
 
+    if(!This->URLName)
+        return E_OUTOFMEMORY;
+
     /* FIXME: If this is a partial URL, try and get a URL moniker from SZ_URLCONTEXT in the bind context,
         then look at pmkToLeft to try and complete the URL
     */