patch 7.4.1161
Problem:    ":argadd" without argument is supposed to add the current buffer
            name to the arglist.
Solution:   Make it work as documented. (Coot, closes #577)
diff --git a/src/testdir/test_arglist.vim b/src/testdir/test_arglist.vim
index 281ac7a..4244344 100644
--- a/src/testdir/test_arglist.vim
+++ b/src/testdir/test_arglist.vim
@@ -57,6 +57,17 @@
   +2argadd y
   call Assert_argc(['a', 'b', 'c', 'x', 'y'])
   call assert_equal(1, argidx())
+
+  %argd
+  edit d
+  arga
+  call assert_equal(len(argv()), 1)
+  call assert_equal(get(argv(), 0, ''), 'd')
+
+  %argd
+  new
+  arga
+  call assert_equal(len(argv()), 0)
 endfunc
 
 func Init_abc()