diff options
| -rw-r--r-- | src/copy.c | 29 |
1 files changed, 11 insertions, 18 deletions
diff --git a/src/copy.c b/src/copy.c index e3c5c523a..49e620afd 100644 --- a/src/copy.c +++ b/src/copy.c @@ -1687,7 +1687,9 @@ copy_internal (char const *src_name, char const *dst_name, } else { - bool link_failed = (link (earlier_file, dst_name) != 0); + /* We want to guarantee that symlinks are not followed. */ + bool link_failed = (linkat (AT_FDCWD, earlier_file, AT_FDCWD, + dst_name, 0) != 0); /* If the link failed because of an existing destination, remove that file and then call link again. */ @@ -1700,7 +1702,8 @@ copy_internal (char const *src_name, char const *dst_name, } if (x->verbose) printf (_("removed %s\n"), quote (dst_name)); - link_failed = (link (earlier_file, dst_name) != 0); + link_failed = (linkat (AT_FDCWD, earlier_file, AT_FDCWD, + dst_name, 0) != 0); } if (link_failed) @@ -1990,25 +1993,15 @@ copy_internal (char const *src_name, char const *dst_name, } } - /* POSIX 2008 states that it is implementation-defined whether - link() on a symlink creates a hard-link to the symlink, or only - to the referent (effectively dereferencing the symlink) (POSIX - 2001 required the latter behavior, although many systems provided - the former). Yet cp, invoked with `--link --no-dereference', - should not follow the link. We can approximate the desired - behavior by skipping this hard-link creating block and instead - copying the symlink, via the `S_ISLNK'- copying code below. - LINK_FOLLOWS_SYMLINKS is tri-state; if it is -1, we don't know - how link() behaves, so we use the fallback case for safety. - - FIXME - use a gnulib linkat emulation for more fine-tuned - emulation, particularly when LINK_FOLLOWS_SYMLINKS is -1. */ + /* cp, invoked with `--link --no-dereference', should not follow the + link; we guarantee this with gnulib's linkat module (on systems + where link(2) follows the link, gnulib creates a symlink with + identical contents, which is good enough for our purposes). */ else if (x->hard_link - && (!LINK_FOLLOWS_SYMLINKS - || !S_ISLNK (src_mode) + && (!S_ISLNK (src_mode) || x->dereference != DEREF_NEVER)) { - if (link (src_name, dst_name)) + if (linkat (AT_FDCWD, src_name, AT_FDCWD, dst_name, 0)) { error (0, errno, _("cannot create link %s"), quote (dst_name)); goto un_backup; |