patch 7.4.1123
Problem: Using ":argadd" when there are no arguments results in the second
argument to be the current one. (Yegappan Lakshmanan)
Solution: Correct the w_arg_idx value.
diff --git a/src/testdir/test_arglist.vim b/src/testdir/test_arglist.vim
index 3f72f0f..5226317 100644
--- a/src/testdir/test_arglist.vim
+++ b/src/testdir/test_arglist.vim
@@ -20,3 +20,55 @@
1argdelete
call assert_equal(0, argidx())
endfunc
+
+func Test_argadd()
+ %argdelete
+ argadd a b c
+ call assert_equal(0, argidx())
+
+ %argdelete
+ argadd a
+ call assert_equal(0, argidx())
+ argadd b c d
+ call assert_equal(0, argidx())
+
+ call Init_abc()
+ argadd x
+ call Assert_argc(['a', 'b', 'x', 'c'])
+ call assert_equal(1, argidx())
+
+ call Init_abc()
+ 0argadd x
+ call Assert_argc(['x', 'a', 'b', 'c'])
+ call assert_equal(2, argidx())
+
+ call Init_abc()
+ 1argadd x
+ call Assert_argc(['a', 'x', 'b', 'c'])
+ call assert_equal(2, argidx())
+
+ call Init_abc()
+ $argadd x
+ call Assert_argc(['a', 'b', 'c', 'x'])
+ call assert_equal(1, argidx())
+
+ call Init_abc()
+ $argadd x
+ +2argadd y
+ call Assert_argc(['a', 'b', 'c', 'x', 'y'])
+ call assert_equal(1, argidx())
+endfunc
+
+func Init_abc()
+ args a b c
+ next
+endfunc
+
+func Assert_argc(l)
+ call assert_equal(len(a:l), argc())
+ let i = 0
+ while i < len(a:l) && i < argc()
+ call assert_equal(a:l[i], argv(i))
+ let i += 1
+ endwhile
+endfunc