Check at least one context is specified

git-svn-id: svn://busybox.net/trunk/busybox@7958 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 3 insertions, 0 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 9ef616b92..c8a2bd385 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -662,6 +662,9 @@ int tar_main(int argc, char **argv)
         if(opt & 0x80000000UL)
                 bb_show_usage();
         ctx_flag = opt & (CTX_CREATE | CTX_TEST | CTX_EXTRACT);
+        if (ctx_flag == 0) {
+                bb_show_usage();
+        }
         if(ctx_flag & CTX_TEST) {
                 if ((tar_handle->action_header == header_list) || 
                         (tar_handle->action_header == header_verbose_list)) {