tests: make sed usage in test-unionrepo.t cross-platform
Usage of the 'i' command proves tricky. I tried to write a check-code rule, but
failed.
--- a/tests/test-unionrepo.t Tue Apr 23 16:57:51 2013 -0500
+++ b/tests/test-unionrepo.t Tue Apr 23 17:26:00 2013 -0500
@@ -26,7 +26,8 @@
$ cd repo2
$ touch repo2-1
$ sed '1i\
- > repo2-1 at top' f > f.tmp
+ > repo2-1 at top
+ > ' f > f.tmp
$ mv f.tmp f
$ hg ci -Aqmrepo2-1
$ touch repo2-2