diff -r f14ad1e83896 -r b21a3753255f docs/tutorial/testlib/topic_setup.sh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/tutorial/testlib/topic_setup.sh	Tue Jan 16 04:41:48 2018 +0100
@@ -0,0 +1,16 @@
+#!/bin/sh
+. $TESTDIR/testlib/pythonpath.sh
+
+# This file holds logic that is used in many tests.
+# It can be called in a test like this:
+#  $ . "$TESTDIR/testlib/topic_setup.sh"
+
+# Enable obsolete markers and enable extensions
+cat >> $HGRCPATH << EOF
+[experimental]
+evolution=createmarkers,exchange
+
+[extensions]
+rebase=
+topic=
+EOF