[PATCH 1 of 5 "] repoview: improve documentation for `repo.filtered` method

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at octobus.net>
# Date 1554540262 -7200
#      Sat Apr 06 10:44:22 2019 +0200
# Node ID 5577867904fc94dc63c4251641e146e087328508
# Parent  509a0477b3a6e9f1ea0fe32bfb028c256aada7fa
# EXP-Topic repoview
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 5577867904fc
repoview: improve documentation for `repo.filtered` method

I am sitting next to Joerg Sonnenberger and we are discussion his experience
with repoview. This first effect of this discussion is this documentation
clarification.

diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1179,7 +1179,17 @@ class localrepository(object):
         return self
 
     def filtered(self, name, visibilityexceptions=None):
-        """Return a filtered version of a repository"""
+        """Return a filtered version of a repository
+
+        The `name` parameter is the identifier of the requested view. This
+        will return a repoview object set "exactly" to the specified view.
+
+        This function does not apply recursive filtering to a repository. For
+        example calling `repo.filtered("served")` will return a repoview using
+        the "served" view, regardless of the initial view used by `repo`.
+
+        In other word, there is always only one level of `repoview` "filtering".
+        """
         cls = repoview.newtype(self.unfiltered().__class__)
         return cls(self, name, visibilityexceptions)