patch 8.2.2221: if <Down> is mapped on the command line 'wildchar' is inserted

Problem:    If <Down> is mapped on the command line 'wildchar' is inserted.
Solution:   Set KeyTyped when using 'wildchar'. (closes #7552)
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 1c5cac7..0127c29 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -58,6 +58,19 @@
   call feedkeys(":e Xdir1/\<Tab>\<Down>\<Up>\<Right>\<CR>", 'tx')
   call assert_equal('testfile1', getline(1))
 
+  +  " <C-J>/<C-K> mappings to go up/down directories when 'wildcharm' is
+  " different than 'wildchar'.
+  set wildcharm=<C-Z>
+  cnoremap <C-J> <Down><C-Z>
+  cnoremap <C-K> <Up><C-Z>
+  call feedkeys(":e Xdir1/\<Tab>\<C-J>\<CR>", 'tx')
+  call assert_equal('testfile3', getline(1))
+  call feedkeys(":e Xdir1/\<Tab>\<C-J>\<C-K>\<CR>", 'tx')
+  call assert_equal('testfile1', getline(1))
+  set wildcharm=0
+  cunmap <C-J>
+  cunmap <C-K>
+
   " Test for canceling the wild menu by adding a character
   redrawstatus
   call feedkeys(":e Xdir1/\<Tab>x\<C-B>\"\<CR>", 'xt')