--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-issue4074.t	Thu Apr 21 22:04:11 2016 -0500
@@ -0,0 +1,29 @@
+#require no-pure
+
+A script to generate nasty diff worst-case scenarios:
+
+  $ cat > s.py <<EOF
+  > import random
+  > for x in xrange(100000):
+  >     print
+  >     if random.randint(0, 100) >= 50:
+  >         x += 1
+  >     print hex(x)
+  > EOF
+
+  $ hg init a
+  $ cd a
+
+Check in a big file:
+
+  $ python ../s.py > a
+  $ hg ci -qAm0
+
+Modify it:
+
+  $ python ../s.py > a
+
+Time a check-in, should never take more than 10 seconds user time:
+
+  $ hg ci --time -m1
+  time: real .* secs .user [0-9][.].* sys .* (re)