patch 9.0.0403: 'equalalways' may be off when 'laststatus' is zero

Problem:    'equalalways' may be off when 'laststatus' is zero.
Solution:   call last_status() before win_equal(). (Luuk van Baal,
            closes #11070)

src/testdir/test_window_cmd.vim

@@ -1617,4 +1617,19 @@ func Test_window_alloc_failure()
   tabonly
 endfunc
 
+func Test_win_equal_last_status()
+  let save_lines = &lines
+  set lines=20
+  set splitbelow
+  set laststatus=0
+
+  split | split | quit
+  call assert_equal(winheight(1), winheight(2))
+
+  let &lines = save_lines
+  set splitbelow&
+  set laststatus&
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab