Merge test suite.
diff --git a/testsuite/cp/cp-preserves-source-file b/testsuite/cp/cp-preserves-source-file
new file mode 100644
index 0000000..f0f5065
--- /dev/null
+++ b/testsuite/cp/cp-preserves-source-file
@@ -0,0 +1,3 @@
+touch foo
+busybox cp foo bar
+test -f foo