Correct wxDirExists() check in OS X wxFileSystemWatcher implementation.

Pass the full path to wxDirExists, not the relative path from the watched
directory as this won't work unless the watched directory is the same as the
current one.

Closes #13161.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67677 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/fswatcher_kqueue.cpp

@@ -314,17 +314,12 @@ protected:
                 wxArrayInt::iterator changeType = changedFlags.begin();
                 for ( ; it != changedFiles.end(); ++it, ++changeType )
                 {
-                    wxFileName path;
-                    if ( wxDirExists(*it) )
-                    {
-                        path = wxFileName::DirName(
-                                basepath + wxFileName::GetPathSeparator() + *it
-                               );
-                    }
-                    else
-                    {
-                        path.Assign(basepath, *it);
-                    }
+                    const wxString fullpath = w.GetPath() +
+                                                wxFileName::GetPathSeparator() +
+                                                  *it;
+                    const wxFileName path(wxDirExists(fullpath)
+                                            ? wxFileName::DirName(fullpath)
+                                            : wxFileName::FileName(fullpath));
 
                     wxFileSystemWatcherEvent event(*changeType, path, path);
                     SendEvent(event);