urlmon: Handle NULL parameter.

dlls/urlmon/tests/misc.c

@@ -1326,6 +1326,14 @@ static void test_MkParseDisplayNameEx(void)
     IBindCtx_Release(bctx);
 }
 
+static void test_IsValidURL(void)
+{
+    HRESULT hr;
+
+    hr = IsValidURL(NULL, 0, 0);
+    ok(hr == E_INVALIDARG, "Expected E_INVALIDARG, got %08x\n", hr);
+}
+
 START_TEST(misc)
 {
     OleInitialize(NULL);
@@ -1345,6 +1353,7 @@ START_TEST(misc)
     test_UrlMkGetSessionOption();
     test_user_agent();
     test_MkParseDisplayNameEx();
+    test_IsValidURL();
 
     OleUninitialize();
 }

dlls/urlmon/urlmon_main.c

@@ -393,10 +393,10 @@ HRESULT WINAPI DllRegisterServerEx(void)
 HRESULT WINAPI IsValidURL(LPBC pBC, LPCWSTR szURL, DWORD dwReserved)
 {
     FIXME("(%p, %s, %d): stub\n", pBC, debugstr_w(szURL), dwReserved);
-    
-    if (pBC != NULL || dwReserved != 0)
+
+    if (pBC || dwReserved || !szURL)
         return E_INVALIDARG;
-    
+
     return S_OK;
 }