[PATCH 2 of 5 FOLLOW-UP] perf: add a docstring to `perfpathcopies`

[Boris Feld]

# HG changeset patch
# User Boris Feld <boris.feld at octobus.net>
# Date 1543187630 -3600
#      Mon Nov 26 00:13:50 2018 +0100
# Node ID 47117f84f39cb5bc12212ba9c31212c9236feb85
# Parent  87443a7ac7f6a37ed59d6429c87118c64b7287f6
# EXP-Topic follow-up-yuya
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 47117f84f39c
perf: add a docstring to `perfpathcopies`

This will help people to find this command.

diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -834,6 +834,7 @@ def perfmergecalculate(ui, repo, rev, **
 
 @command(b'perfpathcopies', [], b"REV REV")
 def perfpathcopies(ui, repo, rev1, rev2, **opts):
+    """benchmark the copy tracing logic"""
     opts = _byteskwargs(opts)
     timer, fm = gettimer(ui, opts)
     ctx1 = scmutil.revsingle(repo, rev1, rev1)
diff --git a/tests/test-contrib-perf.t b/tests/test-contrib-perf.t
--- a/tests/test-contrib-perf.t
+++ b/tests/test-contrib-perf.t
@@ -104,7 +104,7 @@ perfstatus
                  (no help text available)
    perfparents   (no help text available)
    perfpathcopies
-                 (no help text available)
+                 benchmark the copy tracing logic
    perfphases    benchmark phasesets computation
    perfphasesremote
                  benchmark time needed to analyse phases of the remote server