fdo#75968 Fix OUString conversion

Change-Id: Ie865b16c163d47de34ab2fe23bb7432b7710877f
Reviewed-on: https://gerrit.libreoffice.org/8510Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

cui/source/dialogs/hldoctp.cxx

@@ -100,7 +100,7 @@ void SvxHyperlinkDocTp::FillDlgFields(const OUString& rStrURL)
     // set target in document at editfield
     OUString aStrMark;
     if ( nPos != -1 && nPos < rStrURL.getLength()-1 )
-        aStrMark = rStrURL.copy( nPos+1, rStrURL.getLength() );
+        aStrMark = rStrURL.copy( nPos+1, rStrURL.getLength() - nPos - 1 );
      maEdTarget.SetText ( aStrMark );
 
     ModifiedPathHdl_Impl ( NULL );