[PATCH 1 of 2 STABLE] identify: document -r. explicitly how to disable wdir scanning (issue5622)

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1515308218 -32400
#      Sun Jan 07 15:56:58 2018 +0900
# Branch stable
# Node ID 614e385a5245a43232a10ee383d9894673b03b00
# Parent  058c725925e33d70020f590dc44b94e945205c61
identify: document -r. explicitly how to disable wdir scanning (issue5622)

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2690,7 +2690,8 @@ def identify(ui, repo, source=None, rev=
     a list of tags, and a list of bookmarks.
 
     When REV is not given, print a summary of the current state of the
-    repository.
+    repository including the working directory. Specify -r. to get information
+    of the working directory parent without scanning uncommitted changes.
 
     Specifying a path to a repository root or Mercurial bundle will
     cause lookup to operate on that repository/bundle.