Chris Larson (kergoth) writes:

As Manuel points out, this is a flawed fix, and doesnt fix the
following:

mkdir -p cpa cpb cpc
cp -a cpa cpa/cpb/cpc

Attached what appears to be a more sane fix.  Apply on top of previous.
Please confirm sanity.

1 files changed, 6 insertions, 16 deletions

diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 637b8179b..7a13e9968 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -65,28 +65,12 @@ int copy_file(const char *source, const char *dest, int flags)
                 DIR *dp;
                 struct dirent *d;
                 mode_t saved_umask = 0;
-                char *dstparent;
-                struct stat dstparent_stat;
 
                 if (!(flags & FILEUTILS_RECUR)) {
                         bb_error_msg("%s: omitting directory", source);
                         return -1;
                 }
 
-                dstparent = dirname(bb_xstrdup(dest));
-                if (lstat(dstparent, &dstparent_stat) < 0) {
-                        bb_perror_msg("unable to stat `%s'", dstparent);
-                        free(dstparent);
-                        return -1;
-                }
-                free(dstparent);
-
-                if (source_stat.st_dev == dstparent_stat.st_dev &&
-                        source_stat.st_ino == dstparent_stat.st_ino) {
-                        bb_error_msg("cannot copy a directory, `%s', into itself, `%s'", source, dest);
-                        return -1;
-                }
-
                 /* Create DEST.  */
                 if (dest_exists) {
                         if (!S_ISDIR(dest_stat.st_mode)) {
@@ -111,6 +95,8 @@ int copy_file(const char *source, const char *dest, int flags)
                         umask(saved_umask);
                 }
 
+                add_to_ino_dev_hashtable(&dest_stat, source);
+
                 /* Recursively copy files in SOURCE.  */
                 if ((dp = opendir(source)) == NULL) {
                         bb_perror_msg("unable to open directory `%s'", source);
@@ -124,6 +110,10 @@ int copy_file(const char *source, const char *dest, int flags)
                         new_source = concat_subpath_file(source, d->d_name);
                         if(new_source == NULL)
                                 continue;
+                        if (is_in_ino_dev_hashtable(&dest_stat, &new_source)) {
+                                bb_error_msg("cannot copy a directory, `%s', into itself, `%s'", new_source, dest);
+                                continue;
+                        }
                         new_dest = concat_path_file(dest, d->d_name);
                         if (copy_file(new_source, new_dest, flags) < 0)
                                 status = -1;