mshtml: Correctly handle S_OK with NULL URL return from TranslateUrl.

dlls/mshtml/navigate.c

@@ -2324,7 +2324,7 @@ static HRESULT translate_uri(HTMLOuterWindow *window, IUri *orig_uri, BSTR *ret_
 
         hres = IDocHostUIHandler_TranslateUrl(window->doc_obj->hostui, 0, display_uri,
                 &translated_url);
-        if(hres == S_OK) {
+        if(hres == S_OK && translated_url) {
             TRACE("%08x %s -> %s\n", hres, debugstr_w(display_uri), debugstr_w(translated_url));
             SysFreeString(display_uri);
             hres = create_uri(translated_url, 0, &uri);

dlls/mshtml/tests/htmldoc.c

@@ -2614,6 +2614,12 @@ static HRESULT WINAPI DocHostUIHandler_TranslateUrl(IDocHostUIHandler2 *iface, D
     ok(ppchURLOut != NULL, "ppchURLOut == NULL\n");
     ok(!*ppchURLOut, "*ppchURLOut = %p\n", *ppchURLOut);
 
+    /* Not related to hash navigation, just return NULL and S_OK in some cases. */
+    if(loading_hash) {
+        *ppchURLOut = NULL;
+        return S_OK;
+    }
+
     return S_FALSE;
 }