[PATCH] context: make warning message for hidden revision extensible

[Laurent Charignon]

# HG changeset patch
# User Laurent Charignon <lcharignon at fb.com>
# Date 1430761125 25200
#      Mon May 04 10:38:45 2015 -0700
# Node ID 0136dbe8f026cb0a3f8035136d79f8cc05c72857
# Parent  e9edd53770fb77a9787a3e6592a3bf0a29c1bd80
context: make warning message for hidden revision extensible

Extensions might want to create new filternames and change what revisions
are considered hidden or shown. This is the case for inhibit that enables
direct access to hidden hashes with the visible-directaccess-nowarn filtername.
By using startswith instead of a direct comparison with 'visible' we
allow extensions to do that and not work directly on the 'visible' filtername
used by core.

diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -459,7 +459,7 @@
                 pass
         except (error.FilteredIndexError, error.FilteredLookupError,
                 error.FilteredRepoLookupError):
-            if repo.filtername == 'visible':
+            if repo.filtername.startswith('visible'):
                 msg = _("hidden revision '%s'") % changeid
                 hint = _('use --hidden to access hidden revisions')
                 raise error.FilteredRepoLookupError(msg, hint=hint)