Make test-verify SUSv3 compatible.
'head -c' isn't supported on (at least) OpenBSD and is not
part of SUSv3. Instead, use dd.
See also:
http://www.opengroup.org/onlinepubs/
009695399/utilities/head.html
--- a/tests/test-verify Wed Jun 03 22:58:43 2009 -0400
+++ b/tests/test-verify Thu Jun 04 17:33:30 2009 -0600
@@ -35,7 +35,7 @@
hg ci -m a
echo 'corrupted' > b
-head -c 20 .hg/store/data/a.i > start
+dd if=.hg/store/data/a.i of=start bs=1 count=20 2>/dev/null
cat start b > .hg/store/data/a.i
echo