(main): Don't expect array index `n_files - 1' to evaluate

to `-1' for unsigned int n_files == 0.  Doing so lead to a segfault on
alpha.  From Michael Stone.

1 files changed, 2 insertions, 6 deletions

diff --git a/src/mv.c b/src/mv.c
index 3e1e6b96c..71b4de856 100644
--- a/src/mv.c
+++ b/src/mv.c
@@ -464,12 +464,8 @@ main (int argc, char **argv)
   file = argv + optind;
 
   target_directory_specified = (target_directory != NULL);
-  if (target_directory == NULL)
-    {
-      /* Be careful below.  When n_files is 0, this value will be
-	 argv[0], `--', or an option string.  */
-      target_directory = file[n_files - 1];
-    }
+  if (target_directory == NULL && n_files != 0)
+    target_directory = file[n_files - 1];
 
   dest_is_dir = (n_files > 0 && isdir (target_directory));