setting correct 'default' for m_filterIndex, closes #11541

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63178 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/cocoa/filedlg.mm

@@ -154,6 +154,8 @@ int wxFileDialog::ShowModal()
     m_path = wxEmptyString;
     m_fileNames.Clear();
     m_paths.Clear();
+    // since we don't support retrieving the matching filter
+    m_filterIndex = -1;
 
     wxNonOwnedWindow* parentWindow = NULL;
     int returnCode = -1;