patch 9.0.1460: insufficient testing for getcmdcompltype()

Problem:    Insufficient testing for getcmdcompltype().
Solution:   Add a few more test cases. (closes #12268)
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 8b47d86..8b717b7 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -3337,16 +3337,23 @@
   call assert_equal('"!vim test_cmdline.vim', @:)
 endfunc
 
-func Check_completion()
-  call assert_equal('let a', getcmdline())
-  call assert_equal(6, getcmdpos())
-  call assert_equal(7, getcmdscreenpos())
-  call assert_equal('var', getcmdcompltype())
-  return ''
+func Call_cmd_funcs()
+  return string([getcmdpos(), getcmdscreenpos(), getcmdcompltype()])
 endfunc
 
 func Test_screenpos_and_completion()
-  call feedkeys(":let a\<C-R>=Check_completion()\<CR>\<Esc>", "xt")
+  call assert_equal(0, getcmdpos())
+  call assert_equal(0, getcmdscreenpos())
+  call assert_equal('', getcmdcompltype())
+
+  cnoremap <expr> <F2> string([getcmdpos(), getcmdscreenpos(), getcmdcompltype()])
+  call feedkeys(":let a\<F2>\<C-B>\"\<CR>", "xt")
+  call assert_equal("\"let a[6, 7, 'var']", @:)
+  call feedkeys(":quit \<F2>\<C-B>\"\<CR>", "xt")
+  call assert_equal("\"quit [6, 7, '']", @:)
+  call feedkeys(":nosuchcommand \<F2>\<C-B>\"\<CR>", "xt")
+  call assert_equal("\"nosuchcommand [15, 16, '']", @:)
+  cunmap <F2>
 endfunc
 
 func Test_recursive_register()