Add missing test file.

src/testdir/test_cursor_func.vim

@@ -0,0 +1,35 @@
+" Tests for cursor().
+
+func Test_wrong_arguments()
+  try
+    call cursor(1. 3)
+    " not reached
+    call assert_false(1)
+  catch
+    call assert_exception('E474:')
+  endtry
+endfunc
+
+func Test_move_cursor()
+  new
+  call setline(1, ['aaa', 'bbb', 'ccc', 'ddd'])
+
+  call cursor([1, 1, 0, 1])
+  call assert_equal([1, 1, 0, 1], getcurpos()[1:])
+  call cursor([4, 3, 0, 3])
+  call assert_equal([4, 3, 0, 3], getcurpos()[1:])
+
+  call cursor(2, 2)
+  call assert_equal([2, 2, 0, 3], getcurpos()[1:])
+  " line number zero keeps the line number
+  call cursor(0, 1)
+  call assert_equal([2, 1, 0, 3], getcurpos()[1:])
+  " col number zero keeps the column
+  call cursor(3, 0)
+  call assert_equal([3, 1, 0, 3], getcurpos()[1:])
+  " below last line goes to last line
+  call cursor(9, 1)
+  call assert_equal([4, 1, 0, 3], getcurpos()[1:])
+
+  quit!
+endfunc