pager: if old pager extensions is enabled, respect pager.attend

This patch makes us respect pager.attend again if the extension is
enabled. It also brings back the default attend list, so e.g. summary
is not paged by default, just like it used to be before pager was
moved into core.

hgext/pager.py

@@ -64,10 +64,10 b' def uisetup(ui):'
                 # behavior is preserved.
                 ui.setconfig('pager', 'ignore', '', 'pager')
                 ui.pager('extension-via-attend-' + cmd)
+            else:
+                ui.disablepager()
         return orig(ui, options, cmd, cmdfunc)
 
     extensions.wrapfunction(dispatch, '_runcommand', pagecmd)
 
-attended = [
-    'the-default-attend-list-is-now-empty-but-that-breaks-the-extension',
-]
+attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']

tests/test-pager-legacy.t

@@ -50,14 +50,13 b' By default diff and log are paged, but s'
   paged! 'summary:     modify a 9\n'
   paged! '\n'
 
-BROKEN: should not be paged by default
   $ hg summary
-  paged! 'parent: 10:46106edeeb38 tip\n'
-  paged! ' modify a 10\n'
-  paged! 'branch: default\n'
-  paged! 'commit: (clean)\n'
-  paged! 'update: (current)\n'
-  paged! 'phases: 11 draft\n'
+  parent: 10:46106edeeb38 tip
+   modify a 10
+  branch: default
+  commit: (clean)
+  update: (current)
+  phases: 11 draft
 
 We can enable the pager on summary:
 
@@ -79,15 +78,14 b' We can enable the pager on summary:'
   +a 2
 
 If we completely change the attend list that's respected:
-BROKEN: diff should not be paged
   $ hg --config pager.attend=summary diff -c 2
-  paged! 'diff -r f4be7687d414 -r bce265549556 a\n'
-  paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n'
-  paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n'
-  paged! '@@ -1,2 +1,3 @@\n'
-  paged! ' a\n'
-  paged! ' a 1\n'
-  paged! '+a 2\n'
+  diff -r f4be7687d414 -r bce265549556 a
+  --- a/a	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
+  @@ -1,2 +1,3 @@
+   a
+   a 1
+  +a 2
 
 If 'log' is in attend, then 'history' should also be paged:
   $ hg history --limit 2 --config pager.attend=log