purge: restore the `testedwith` declaration

Otherwise, this extension gets highlighted as a 3rd party extension when an
exception occurs.

Differential Revision: https://phab.mercurial-scm.org/D10895

hgext/purge.py

@@ -1,32 +1,38
 # Copyright (C) 2006 - Marco Barisione <[e-mail]>
 #
 # This is a small extension for Mercurial (https://mercurial-scm.org/)
 # that removes files not known to mercurial
 #
 # This program was inspired by the "cvspurge" script contained in CVS
 # utilities (http://www.red-bean.com/cvsutils/).
 #
 # For help on the usage of "hg purge" use:
 #  hg help purge
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <http://www.gnu.org/licenses/>.
 
 '''command to delete untracked files from the working directory (DEPRECATED)
 
 The functionality of this extension has been included in core Mercurial since
 version 5.7. Please use :hg:`purge ...` instead. :hg:`purge --confirm` is now the default, unless the extension is enabled for backward compatibility.
 '''
 
 # This empty extension looks pointless, but core mercurial checks if it's loaded
 # to implement the slightly different behavior documented above.
+
+# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
+# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
+# be specifying the version(s) of Mercurial they are tested with, or
+# leave the attribute unspecified.
+testedwith = b'ships-with-hg-core'