configitems: register the 'pager.attend' config

hgext/pager.py

@@ -28,6 +28,7 b' from mercurial import ('
     commands,
     dispatch,
     extensions,
+    registrar,
     )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
@@ -36,13 +37,20 b' from mercurial import ('
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
+configtable = {}
+configitem = registrar.configitem(configtable)
+
+configitem('pager', 'attend',
+        default=lambda: attended,
+)
+
 def uisetup(ui):
 
     def pagecmd(orig, ui, options, cmd, cmdfunc):
         auto = options['pager'] == 'auto'
         if auto and not ui.pageractive:
             usepager = False
-            attend = ui.configlist('pager', 'attend', attended)
+            attend = ui.configlist('pager', 'attend')
             ignore = ui.configlist('pager', 'ignore')
             cmds, _ = cmdutil.findcmd(cmd, commands.table)