Add wxDIR_NO_FOLLOW flag for wxDir iteration.

This flag allows to avoid following the symbolic links during the directory
traversal. In particular, this means that links to the directories
(potentially outside the directory being traversed) are not considered as
directories at all when it is used, potentially avoiding surprises.

Closes #14542.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72740 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/dir.cpp

@@ -150,10 +150,13 @@ bool wxDirData::Read(wxString *filename)
             break;
         }
 
-        // check the type now: notice that we want to check the type of this
-        // path itself and not whatever it points to in case of a symlink
+        // check the type now: notice that we may want to check the type of
+        // the path itself and not whatever it points to in case of a symlink
         wxFileName fn = wxFileName::DirName(path + de_d_name);
-        fn.DontFollowLink();
+        if ( m_flags & wxDIR_NO_FOLLOW )
+        {
+            fn.DontFollowLink();
+        }
 
         if ( !(m_flags & wxDIR_FILES) && !fn.DirExists() )
         {