[PATCH] cp: do not create empty dst file if failed to make reflink

[Guangyu Sun]

If making reflink across devices or if the filesystem does not support
reflink, we want it to return an error and do nothing else. However,
now it will create a new empty file to the dst. Fix it.

test case in an ext4 filesystem:
$ ls
foo
$ cp --reflink foo bar
cp: failed to clone `bar': Inappropriate ioctl for device
$ ls
foo     bar
$

Signed-off-by: Guangyu Sun <address@hidden>
---
 src/copy.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/copy.c b/src/copy.c
index 5c0ee1e..b323876 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -1176,6 +1176,9 @@ close_src_and_dst_desc:
       error (0, errno, _("failed to close %s"), quote (dst_name));
       return_val = false;
     }
+  if (! return_val && *new_dst)
+    if (unlink (dst_name))
+      error (0, errno, _("cannot remove %s"), quote (dst_name));
 close_src_desc:
   if (close (source_desc) < 0)
     {
--
1.7.9.5