[PATCH] Make test-hardlinks-safety portable

[Christian Ebert]

Play it again with terser commit message.

>From man cp on MacOS X:


|Note that cp copies hard linked files as separate files.  If you
|need to preserve hard links, consider using tar(1), cpio(1), or
|pax(1) instead.

c

# HG changeset patch
# User Christian Ebert <blacktrash at gmx.net>
# Date 1218791761 -7200
# Node ID 52a83161a11af98695c276b7975bd5f31965a2f5
# Parent  438e02b4be73ffd80d4a6cc45b7c9273d6b26604
Make test-hardlinks-safety portable

On some systems (MacOS X) cp does not preserve hardlinks.
Use tar instead.

diff --git a/tests/test-hardlinks-safety b/tests/test-hardlinks-safety
--- a/tests/test-hardlinks-safety
+++ b/tests/test-hardlinks-safety
@@ -21,7 +21,9 @@
 hg qpush
 
 cd ..
-cp -al a b
+mkdir x
+tar -cf - a | tar xf - -C x
+mv x/a b
 cd b
 
 hg qimport -n bar - << EOF
@@ -51,7 +53,8 @@
 hg tag foo
 
 cd ..
-cp -al b c
+tar -cf - b | tar xf - -C x
+mv x/b c
 cd c
 
 hg tag -l -r 0 lbar