Merge branch 'jk/close-duped-fd-before-unlock-for-bundle'

When "git bundle" aborts due to an empty commit ranges
(i.e. resulting in an empty pack), it left a file descriptor to an
lockfile open, which resulted in leftover lockfile on Windows where
you cannot remove a file with an open file descriptor.  This has
been corrected.

* jk/close-duped-fd-before-unlock-for-bundle:
  bundle: dup() output descriptor closer to point-of-use

t/t5607-clone-bundle.sh

@@ -71,4 +71,10 @@ test_expect_success 'prerequisites with an empty commit message' '
 	git bundle verify bundle
 '
 
+test_expect_success 'failed bundle creation does not leave cruft' '
+	# This fails because the bundle would be empty.
+	test_must_fail git bundle create fail.bundle master..master &&
+	test_path_is_missing fail.bundle.lock
+'
+
 test_done