tar: fix a bug where autodetection messes up -z on extract

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/archival/tar.c b/archival/tar.c
index e9dc41fe1..1e3cecf44 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -1060,8 +1060,10 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
                         tar_handle->src_fd = tar_fd;
                         tar_handle->seek = seek_by_read;
                 } else {
-                        if (ENABLE_FEATURE_TAR_AUTODETECT && flags == O_RDONLY) {
-                                get_header_ptr = get_header_tar;
+                        if (ENABLE_FEATURE_TAR_AUTODETECT
+                         && flags == O_RDONLY
+                         && get_header_ptr == get_header_tar
+                        ) {
                                 tar_handle->src_fd = open_zipped(tar_filename);
                                 if (tar_handle->src_fd < 0)
                                         bb_perror_msg_and_die("can't open '%s'", tar_filename);