[PATCH] backout: add example of backing out a merge changeset

[Mathias De Maré]

# HG changeset patch
# User Mathias De Maré <mathias.demare at gmail.com>
# Date 1443590812 -7200
#      Wed Sep 30 07:26:52 2015 +0200
# Node ID 5a00a9ab705848b7de45b4263ed0bbab29494e29
# Parent  46af0adb5c375cc51ce0d29cbdcd8ba843a33425
backout: add example of backing out a merge changeset

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -495,6 +495,19 @@
       cancel the merge and leave the child of REV as a head to be
       merged separately.
 
+      Examples:
+
+      - do a backout of a merge changeset 33 that was created from
+        a good changeset 22 and a bad changeset 11::
+
+          hg backout -r 33 --parent 22
+          hg commit -m "Backout of merge 33 to parent 22"
+
+        After the backout, all of the changes on
+        the good side of the merge (the side of changeset 22 and ancestors)
+        are kept, while the changes on the bad side of the merge
+        (the side of changeset 11 and ancestors) are backed out.
+
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Returns 0 on success, 1 if nothing to backout or there are unresolved